Add support for running LLVM optimizer. (#6225)

Adds a flag `--optimize=<mode>` that specifies what to optimize for:

* `--optimize=none` turns off the optimizer as much as possible, but
still respects always_inline.
* `--optimize=debug` aims to be the equivalent of `-Og` / `-O1`, and
provides optimizations that don't affect the ability to debug the
program. This is the default.
* `--optimize=size` optimizes for the size of the produced program, and
aims to be the equivalent of `-Oz`.
* `--optimize=speed` optimizes for the execution time of the produced
program, and aims to be the equivalent of `-O3`.

Following the approach taken by Clang, the optimization level feeds into
both the configuration of the LLVM pass pipeline and the attributes
added to function definitions generated by the frontend.

Optimization is performed in a new phase, `optimize`, which runs between
`lower` and `codegen`.

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>

toolchain/autoupdate_testdata.py

@@ -51,10 +51,10 @@ def main() -> None:
     args = parser.parse_args()
 
     if args.non_fatal_checks:
-        if build_mode == "opt":
+        if build_mode == "optimize":
             exit(
                 "`--non-fatal-checks` is incompatible with inferred "
-                "`-c opt` build mode"
+                "`-c optimize` build mode"
             )
         configs.append("--config=non-fatal-checks")
 

toolchain/check/testdata/interop/cpp/function/thunk_ast.carbon

@@ -64,7 +64,7 @@ auto foo(short a) -> void;
 // CHECK:STDOUT: | |-ParmVarDecl {{0x[a-f0-9]+}} <<invalid sloc>> <invalid sloc> implicit 'std::align_val_t'
 // CHECK:STDOUT: | `-VisibilityAttr {{0x[a-f0-9]+}} <<invalid sloc>> Implicit Default
 // CHECK:STDOUT: |-FunctionDecl {{0x[a-f0-9]+}} <<carbon-internal>:8:1, line:14:1> line:8:7 operator new 'void *(unsigned long, void *) noexcept'
-// CHECK:STDOUT: | |-ParmVarDecl {{0x[a-f0-9]+}} <<built-in>:173:23, col:37> <carbon-internal>:8:33 'unsigned long'
+// CHECK:STDOUT: | |-ParmVarDecl {{0x[a-f0-9]+}} <<built-in>:174:23, col:37> <carbon-internal>:8:33 'unsigned long'
 // CHECK:STDOUT: | `-ParmVarDecl {{0x[a-f0-9]+}} <col:35, col:39> col:40 'void *'
 // CHECK:STDOUT: `-FunctionDecl {{0x[a-f0-9]+}} <./thunk_required.h:[[@LINE-51]]:6> col:6 foo__carbon_thunk 'void (short * _Nonnull)' extern
 // CHECK:STDOUT:   |-ParmVarDecl {{0x[a-f0-9]+}} <col:6> col:6 used a 'short * _Nonnull':'short *'

toolchain/codegen/codegen.cpp

@@ -17,27 +17,6 @@
 
 namespace Carbon {
 
-auto CodeGen::Make(llvm::Module* module, llvm::StringRef target_triple_str,
-                   Diagnostics::Consumer* consumer) -> std::optional<CodeGen> {
-  llvm::Triple target_triple(target_triple_str);
-  std::string error;
-  const llvm::Target* target =
-      llvm::TargetRegistry::lookupTarget(target_triple, error);
-  CARBON_CHECK(target, "Target should be validated before codegen: {0}", error);
-
-  module->setTargetTriple(target_triple);
-
-  constexpr llvm::StringLiteral CPU = "generic";
-  constexpr llvm::StringLiteral Features = "";
-
-  llvm::TargetOptions target_opts;
-  CodeGen codegen(module,
-                  consumer ? consumer : &Diagnostics::ConsoleConsumer());
-  codegen.target_machine_.reset(target->createTargetMachine(
-      target_triple, CPU, Features, target_opts, llvm::Reloc::PIC_));
-  return codegen;
-}
-
 auto CodeGen::EmitAssembly(llvm::raw_pwrite_stream& out) -> bool {
   return EmitCode(out, llvm::CodeGenFileType::AssemblyFile);
 }

toolchain/codegen/codegen.h

@@ -14,11 +14,10 @@ namespace Carbon {
 
 class CodeGen {
  public:
-  // `module` and `errors` must not be null. `consumer` may be null, in which
-  // case diagnostics go to stderr.
-  static auto Make(llvm::Module* module, llvm::StringRef target_triple_str,
-                   Diagnostics::Consumer* consumer = nullptr)
-      -> std::optional<CodeGen>;
+  // `module`, `target_machine`, and `consumer` must not be null.
+  explicit CodeGen(llvm::Module* module, llvm::TargetMachine* target_machine,
+                   Diagnostics::Consumer* consumer)
+      : module_(module), target_machine_(target_machine), emitter_(consumer) {}
 
   // Generates the object code file.
   // Returns false in case of failure, and any information about the failure is
@@ -35,10 +34,6 @@ class CodeGen {
   auto EmitAssembly(llvm::raw_pwrite_stream& out) -> bool;
 
  private:
-  // `module` and `consumer` must not be null.
-  explicit CodeGen(llvm::Module* module, Diagnostics::Consumer* consumer)
-      : module_(module), emitter_(consumer) {}
-
   // Using the llvm pass emits either assembly or object code to dest.
   // Returns false in case of failure, and any information about the failure is
   // printed to the error stream.
@@ -47,10 +42,10 @@ class CodeGen {
 
   llvm::Module* module_;
 
+  llvm::TargetMachine* target_machine_;
+
   // The emitter for diagnostics.
   Diagnostics::FileEmitter emitter_;
-
-  std::unique_ptr<llvm::TargetMachine> target_machine_;
 };
 
 }  // namespace Carbon

toolchain/driver/BUILD

@@ -155,6 +155,7 @@ cc_library(
         "//toolchain/language_server",
         "//toolchain/lex",
         "//toolchain/lower",
+        "//toolchain/lower:options",
         "//toolchain/parse",
         "//toolchain/parse:tree",
         "//toolchain/sem_ir:file",
@@ -162,6 +163,7 @@ cc_library(
         "//toolchain/source:source_buffer",
         "@llvm-project//llvm:Core",
         "@llvm-project//llvm:MC",
+        "@llvm-project//llvm:Passes",
         "@llvm-project//llvm:Support",
         "@llvm-project//llvm:TargetParser",
     ],

toolchain/driver/compile_subcommand.cpp

@@ -16,6 +16,9 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/ScopeExit.h"
 #include "llvm/MC/TargetRegistry.h"
+#include "llvm/Passes/OptimizationLevel.h"
+#include "llvm/Passes/PassBuilder.h"
+#include "llvm/Passes/StandardInstrumentations.h"
 #include "toolchain/base/clang_invocation.h"
 #include "toolchain/base/timings.h"
 #include "toolchain/check/check.h"
@@ -60,6 +63,7 @@ compile to machine code.
                 arg_b.OneOfValue("parse", Phase::Parse),
                 arg_b.OneOfValue("check", Phase::Check),
                 arg_b.OneOfValue("lower", Phase::Lower),
+                arg_b.OneOfValue("optimize", Phase::Optimize),
                 arg_b.OneOfValue("codegen", Phase::CodeGen).Default(true),
             },
             &phase);
@@ -109,6 +113,33 @@ object output can be forced by enabling `--force-obj-output`.
       },
       [&](auto& arg_b) { arg_b.Set(&output_filename); });
 
+  b.AddOneOfOption(
+      {
+          .name = "optimize",
+          .help = R"""(
+Selects the amount of optimization to perform.
+)""",
+      },
+      [&](auto& arg_b) {
+        arg_b.SetOneOf(
+            {
+                // We intentionally don't expose O2 and Os. The difference
+                // between these levels tends to reflect what achieves the
+                // best speed for a specific application, as they all
+                // largely optimize for speed as the primary factor.
+                //
+                // Instead of controlling this with more nuanced flags, we
+                // plan to support profile and in-source hints to the
+                // optimizer to adjust its strategy in the specific places
+                // where the default doesn't have the desired results.
+                arg_b.OneOfValue("none", Lower::OptimizationLevel::None),
+                arg_b.OneOfValue("debug", Lower::OptimizationLevel::Debug),
+                arg_b.OneOfValue("speed", Lower::OptimizationLevel::Speed),
+                arg_b.OneOfValue("size", Lower::OptimizationLevel::Size),
+            },
+            &opt_level);
+      });
+
   // Include the common code generation options at this point to render it
   // after the more common options above, but before the more unusual options
   // below.
@@ -368,6 +399,8 @@ static auto PhaseToString(CompileOptions::Phase phase) -> std::string {
       return "check";
     case CompileOptions::Phase::Lower:
       return "lower";
+    case CompileOptions::Phase::Optimize:
+      return "optimize";
     case CompileOptions::Phase::CodeGen:
       return "codegen";
   }
@@ -408,6 +441,7 @@ auto CompileSubcommand::ValidateOptions(
       }
       [[fallthrough]];
     case Phase::Lower:
+    case Phase::Optimize:
     case Phase::CodeGen:
       // Everything can be dumped in these phases.
       break;
@@ -422,11 +456,12 @@ class MultiUnitCache;
 // Ties together information for a file being compiled.
 class CompilationUnit {
  public:
-  // `driver_env`, `options`, and `consumer` must be non-null.
+  // `driver_env`, `options`, `consumer`, and `target` must be non-null.
   explicit CompilationUnit(SemIR::CheckIRId check_ir_id, int total_ir_count,
                            DriverEnv* driver_env, const CompileOptions* options,
                            Diagnostics::Consumer* consumer,
-                           llvm::StringRef input_filename);
+                           llvm::StringRef input_filename,
+                           const llvm::Target* target);
 
   // Sets the multi-unit cache and initializes dependent member state.
   auto SetMultiUnitCache(MultiUnitCache* cache) -> void;
@@ -446,6 +481,14 @@ class CompilationUnit {
   // Lower SemIR to LLVM IR.
   auto RunLower() -> void;
 
+  // Runs the optimization pipeline.
+  auto RunOptimize() -> void;
+
+  // Runs post-lowering-to-LLVM-IR logic. This is always called if we do any
+  // lowering work, after we've finished building the IR in RunLower() and,
+  // optionally, RunOptimize().
+  auto PostLower() -> void;
+
   auto RunCodeGen() -> void;
 
   // Runs post-compile logic. This is always called, and called after all other
@@ -484,6 +527,9 @@ class CompilationUnit {
   // Returns true if the current file should be included in debug dumps.
   auto IncludeInDumps() -> bool;
 
+  // Builds the LLVM target machine.
+  auto MakeTargetMachine() -> void;
+
   // The index of the unit amongst all units.
   SemIR::CheckIRId check_ir_id_;
   // The number of units in total.
@@ -491,6 +537,7 @@ class CompilationUnit {
 
   DriverEnv* driver_env_;
   const CompileOptions* options_;
+  const llvm::Target* target_;
 
   SharedValueStores value_stores_;
 
@@ -527,6 +574,7 @@ class CompilationUnit {
   std::unique_ptr<clang::ASTUnit> clang_ast_unit_;
   std::unique_ptr<llvm::LLVMContext> llvm_context_;
   std::unique_ptr<llvm::Module> module_;
+  std::unique_ptr<llvm::TargetMachine> target_machine_;
 };
 
 // Caches lists that are shared cross-unit. Accessors do lazy caching because
@@ -611,11 +659,13 @@ CompilationUnit::CompilationUnit(SemIR::CheckIRId check_ir_id,
                                  int total_ir_count, DriverEnv* driver_env,
                                  const CompileOptions* options,
                                  Diagnostics::Consumer* consumer,
-                                 llvm::StringRef input_filename)
+                                 llvm::StringRef input_filename,
+                                 const llvm::Target* target)
     : check_ir_id_(check_ir_id),
       total_ir_count_(total_ir_count),
       driver_env_(driver_env),
       options_(options),
+      target_(target),
       input_filename_(input_filename),
       vlog_stream_(driver_env_->vlog_stream) {
   if (vlog_stream_ != nullptr || options_->stream_errors) {
@@ -743,15 +793,149 @@ auto CompilationUnit::RunLower() -> void {
         options_->run_llvm_verifier ? driver_env_->error_stream : nullptr;
     options.want_debug_info = options_->include_debug_info;
     options.vlog_stream = vlog_stream_;
-    if (options_->dump_llvm_ir && IncludeInDumps()) {
-      options.dump_stream = driver_env_->output_stream;
-    }
+    options.opt_level = options_->opt_level;
     module_ = Lower::LowerToLLVM(*llvm_context_, driver_env_->fs,
                                  cache_->tree_and_subtrees_getters(), *sem_ir_,
                                  total_ir_count_, options);
   });
 }
 
+auto CompilationUnit::MakeTargetMachine() -> void {
+  CARBON_CHECK(module_, "Must call RunLower first");
+  CARBON_CHECK(!target_machine_, "Should not call this multiple times");
+
+  // Set the target on the module.
+  // TODO: We should do this earlier. Lower should be passed the target triple
+  // so it can create the module with this already set.
+  llvm::Triple target_triple(options_->codegen_options.target);
+  module_->setTargetTriple(target_triple);
+
+  // TODO: Provide flags to control these.
+  constexpr llvm::StringLiteral CPU = "generic";
+  constexpr llvm::StringLiteral Features = "";
+
+  llvm::TargetOptions target_opts;
+  target_machine_.reset(target_->createTargetMachine(
+      target_triple, CPU, Features, target_opts, llvm::Reloc::PIC_));
+}
+
+// Get the LLVM optimization level corresponding to a Carbon optimization level.
+static auto GetLLVMOptimizationLevel(Lower::OptimizationLevel opt_level)
+    -> llvm::OptimizationLevel {
+  switch (opt_level) {
+    case Lower::OptimizationLevel::None:
+      return llvm::OptimizationLevel::O0;
+    case Lower::OptimizationLevel::Debug:
+      return llvm::OptimizationLevel::O1;
+    case Lower::OptimizationLevel::Size:
+      return llvm::OptimizationLevel::Oz;
+    case Lower::OptimizationLevel::Speed:
+      return llvm::OptimizationLevel::O3;
+  }
+}
+
+// Get the `-O` flag corresponding to an optimization level.
+static auto GetClangOptimizationFlag(Lower::OptimizationLevel opt_level)
+    -> llvm::StringLiteral {
+  switch (opt_level) {
+    case Lower::OptimizationLevel::None:
+      return "-O0";
+    case Lower::OptimizationLevel::Debug:
+      return "-O1";
+    case Lower::OptimizationLevel::Size:
+      return "-Oz";
+    case Lower::OptimizationLevel::Speed:
+      return "-O3";
+  }
+}
+
+auto CompilationUnit::RunOptimize() -> void {
+  CARBON_CHECK(module_, "Must call RunLower first");
+
+  // TODO: A lot of the work done here duplicates work done by Clang setting up
+  // its pass manager. Moreover, we probably want to pick up Clang's
+  // customizations and make use of its flags for controlling LLVM passes. We
+  // should consider whether we would be better off running Clang's pass
+  // pipeline rather than building one of our own, or factoring out enough of
+  // Clang's pipeline builder that we can reuse and further customize it.
+
+  MakeTargetMachine();
+
+  // TODO: There's no way to set these automatically from an
+  // llvm::OptimizationLevel. Add such a mechanism to LLVM and use it from
+  // here. For now we reconstruct what Clang does by default.
+  llvm::PipelineTuningOptions pto;
+  bool opt_for_speed = options_->opt_level == Lower::OptimizationLevel::Speed;
+  bool opt_for_size_or_speed =
+      opt_for_speed || options_->opt_level == Lower::OptimizationLevel::Size;
+  // Loop unrolling is enabled by `--optimize=size` but isn't actually performed
+  // because we add `optsize` attributes to the function definitions we emit.
+  pto.LoopUnrolling = opt_for_size_or_speed;
+  pto.LoopInterleaving = opt_for_size_or_speed;
+  pto.LoopVectorization = opt_for_speed;
+  pto.SLPVectorization = opt_for_size_or_speed;
+
+  llvm::LoopAnalysisManager lam;
+  llvm::FunctionAnalysisManager fam;
+  llvm::CGSCCAnalysisManager cgam;
+  llvm::ModuleAnalysisManager mam;
+
+  llvm::PassInstrumentationCallbacks pic;
+
+  // Register standard pass instrumentations. This adds support for things like
+  // `-print-after-all`.
+  llvm::StandardInstrumentations si(module_->getContext(),
+                                    /*DebugLogging=*/false);
+  si.registerCallbacks(pic);
+
+  llvm::PassBuilder builder(target_machine_.get(), pto,
+                            /*PGOOpt=*/std::nullopt, &pic);
+
+  // TODO: Add an AssignmentTrackingPass for at least `--optimize=debug`.
+
+  // Set up target library information and add an analysis pass to supply it.
+  std::unique_ptr<llvm::TargetLibraryInfoImpl> tlii(llvm::driver::createTLII(
+      module_->getTargetTriple(), llvm::driver::VectorLibrary::NoLibrary));
+  fam.registerPass([&] { return llvm::TargetLibraryAnalysis(*tlii); });
+
+  builder.registerModuleAnalyses(mam);
+  builder.registerCGSCCAnalyses(cgam);
+  builder.registerFunctionAnalyses(fam);
+  builder.registerLoopAnalyses(lam);
+  builder.crossRegisterProxies(lam, fam, cgam, mam);
+
+  llvm::ModulePassManager pass_manager = builder.buildPerModuleDefaultPipeline(
+      GetLLVMOptimizationLevel(options_->opt_level));
+
+  if (vlog_stream_) {
+    CARBON_VLOG("*** Running pass pipeline: ");
+    pass_manager.printPipeline(
+        *vlog_stream_, [&pic](llvm::StringRef class_name) {
+          auto pass_name = pic.getPassNameForClassName(class_name);
+          return pass_name.empty() ? class_name : pass_name;
+        });
+    CARBON_VLOG(" ***\n");
+  }
+
+  LogCall("ModulePassManager::run", "optimize",
+          [&] { pass_manager.run(*module_, mam); });
+
+  if (vlog_stream_) {
+    CARBON_VLOG("*** Optimized llvm::Module ***\n");
+    module_->print(*vlog_stream_, /*AAW=*/nullptr,
+                   /*ShouldPreserveUseListOrder=*/false,
+                   /*IsForDebug=*/true);
+  }
+}
+
+auto CompilationUnit::PostLower() -> void {
+  CARBON_CHECK(module_, "Must call RunLower first");
+  if (options_->dump_llvm_ir && IncludeInDumps()) {
+    module_->print(*driver_env_->output_stream, /*AAW=*/nullptr,
+                   /*ShouldPreserveUseListOrder=*/true);
+  }
+}
+
 auto CompilationUnit::RunCodeGen() -> void {
   CARBON_CHECK(module_, "Must call RunLower first");
   LogCall("CodeGen", "codegen", [&] { success_ = RunCodeGenHelper(); });
@@ -778,14 +962,13 @@ auto CompilationUnit::PostCompile() -> void {
 }
 
 auto CompilationUnit::RunCodeGenHelper() -> bool {
-  std::optional<CodeGen> codegen =
-      CodeGen::Make(module_.get(), options_->codegen_options.target, consumer_);
-  if (!codegen) {
-    return false;
-  }
+  CARBON_CHECK(module_, "Must call RunLower first");
+  CARBON_CHECK(target_machine_, "Must call MakeTargetMachine first");
+
+  CodeGen codegen(module_.get(), target_machine_.get(), consumer_);
   if (vlog_stream_) {
     CARBON_VLOG("*** Assembly ***\n");
-    codegen->EmitAssembly(*vlog_stream_);
+    codegen.EmitAssembly(*vlog_stream_);
   }
 
   if (options_->output_filename == "-") {
@@ -793,11 +976,11 @@ auto CompilationUnit::RunCodeGenHelper() -> bool {
     // textual assembly output are all somewhat linked flags. We should add
     // some validation that they are used correctly.
     if (options_->force_obj_output) {
-      if (!codegen->EmitObject(*driver_env_->output_stream)) {
+      if (!codegen.EmitObject(*driver_env_->output_stream)) {
         return false;
       }
     } else {
-      if (!codegen->EmitAssembly(*driver_env_->output_stream)) {
+      if (!codegen.EmitAssembly(*driver_env_->output_stream)) {
         return false;
       }
     }
@@ -841,11 +1024,11 @@ auto CompilationUnit::RunCodeGenHelper() -> bool {
       return false;
     }
     if (options_->asm_output) {
-      if (!codegen->EmitAssembly(output_file)) {
+      if (!codegen.EmitAssembly(output_file)) {
         return false;
       }
     } else {
-      if (!codegen->EmitObject(output_file)) {
+      if (!codegen.EmitObject(output_file)) {
         return false;
       }
     }
@@ -910,6 +1093,10 @@ auto CompileSubcommand::Run(DriverEnv& driver_env) -> DriverResult {
         // defaults to be more stable.
         // TODO: Decide if we want this.
         "-fPIE",
+        // Propagate our optimization level to Clang as a default. This can be
+        // overridden by Clang arguments, but doing so will only have an effect
+        // if those arguments affect Clang's IR, not its pass pipeline.
+        GetClangOptimizationFlag(options_.opt_level).str(),
     };
     if (driver_env.fuzzing && !options_.clang_args.empty()) {
       // Parsing specific Clang arguments can reach deep into
@@ -925,6 +1112,9 @@ auto CompileSubcommand::Run(DriverEnv& driver_env) -> DriverResult {
     if (!clang_invocation) {
       return {.success = false};
     }
+    // We will run our own pass pipeline over the IR in the `Optimize` phase, so
+    // disable Clang's pipeline to avoid optimizing C++ code twice.
+    clang_invocation->getCodeGenOpts().DisableLLVMPasses = true;
   }
 
   // Find the files comprising the prelude if we are importing it.
@@ -952,7 +1142,7 @@ auto CompileSubcommand::Run(DriverEnv& driver_env) -> DriverResult {
     ++unit_index;
     return std::make_unique<CompilationUnit>(
         SemIR::CheckIRId(unit_index), total_unit_count, &driver_env, &options_,
-        &driver_env.consumer, filename);
+        &driver_env.consumer, filename, target);
   };
   llvm::append_range(units, llvm::map_range(prelude, unit_builder));
   llvm::append_range(units,
@@ -1079,11 +1269,18 @@ auto CompileSubcommand::Run(DriverEnv& driver_env) -> DriverResult {
     return make_result();
   }
 
-  // Lower.
+  // Lower and optimize.
   for (const auto& unit : units) {
     unit->RunLower();
+
+    if (options_.phase != CompileOptions::Phase::Lower) {
+      unit->RunOptimize();
+    }
+
+    unit->PostLower();
   }
-  if (options_.phase == CompileOptions::Phase::Lower) {
+  if (options_.phase == CompileOptions::Phase::Lower ||
+      options_.phase == CompileOptions::Phase::Optimize) {
     return make_result();
   }
   CARBON_CHECK(options_.phase == CompileOptions::Phase::CodeGen,

toolchain/driver/compile_subcommand.h

@@ -14,6 +14,7 @@
 #include "toolchain/driver/codegen_options.h"
 #include "toolchain/driver/driver_env.h"
 #include "toolchain/driver/driver_subcommand.h"
+#include "toolchain/lower/options.h"
 
 namespace Carbon {
 
@@ -26,6 +27,7 @@ struct CompileOptions {
     Parse,
     Check,
     Lower,
+    Optimize,
     CodeGen,
   };
 
@@ -34,6 +36,7 @@ struct CompileOptions {
 
   auto Build(CommandLine::CommandBuilder& b) -> void;
 
+  Lower::OptimizationLevel opt_level = Lower::OptimizationLevel::Debug;
   CodegenOptions codegen_options;
 
   Phase phase;

toolchain/driver/testdata/compile/optimize/clang_no_optimize_twice.carbon

@@ -0,0 +1,74 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// ARGS: compile --optimize=none foo.carbon --target=x86_64-unknown-linux-gnu --phase=optimize --dump-llvm-ir --exclude-dump-file-prefix=%{core} --clang-arg=-O3
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/driver/testdata/compile/optimize/clang_no_optimize_twice.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/compile/optimize/clang_no_optimize_twice.carbon
+
+// --- foo.carbon
+
+import Cpp inline '''c++
+// This should not be `optnone`, because Clang had `-O3`.
+inline int f() { return 42; }
+
+// The call to `f()` should not be inlined because Carbon had `--optimize=none`,
+// so we don't run the inliner.
+int g() { return f(); }
+''';
+
+// This should be emitted `optnone`.
+fn Call() -> i32 {
+  return Cpp.g();
+}
+
+// CHECK:STDOUT: ; ModuleID = 'foo.carbon'
+// CHECK:STDOUT: source_filename = "foo.carbon"
+// CHECK:STDOUT: target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+// CHECK:STDOUT: target triple = "x86_64-unknown-linux-gnu"
+// CHECK:STDOUT:
+// CHECK:STDOUT: $_Z1fv = comdat any
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: noinline nounwind optnone
+// CHECK:STDOUT: define i32 @_CCall.Main() #0 !dbg !7 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %g.call = call i32 @_Z1gv(), !dbg !10
+// CHECK:STDOUT:   ret i32 %g.call, !dbg !11
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: mustprogress noinline optnone
+// CHECK:STDOUT: define dso_local i32 @_Z1gv() #1 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %call = call i32 @_Z1fv()
+// CHECK:STDOUT:   ret i32 %call
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: mustprogress noinline nounwind optnone
+// CHECK:STDOUT: define linkonce_odr dso_local i32 @_Z1fv() #2 comdat {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   ret i32 42
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { noinline nounwind optnone }
+// CHECK:STDOUT: attributes #1 = { mustprogress noinline optnone "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="0" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+// CHECK:STDOUT: attributes #2 = { mustprogress noinline nounwind optnone "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="0" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !llvm.module.flags = !{!0, !1, !2, !3, !4}
+// CHECK:STDOUT: !llvm.dbg.cu = !{!5}
+// CHECK:STDOUT:
+// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
+// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
+// CHECK:STDOUT: !2 = !{i32 1, !"wchar_size", i32 4}
+// CHECK:STDOUT: !3 = !{i32 8, !"PIC Level", i32 0}
+// CHECK:STDOUT: !4 = !{i32 7, !"PIE Level", i32 2}
+// CHECK:STDOUT: !5 = distinct !DICompileUnit(language: DW_LANG_C, file: !6, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !6 = !DIFile(filename: "foo.carbon", directory: "")
+// CHECK:STDOUT: !7 = distinct !DISubprogram(name: "Call", linkageName: "_CCall.Main", scope: null, file: !6, line: 12, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !8 = !DISubroutineType(types: !9)
+// CHECK:STDOUT: !9 = !{}
+// CHECK:STDOUT: !10 = !DILocation(line: 13, column: 10, scope: !7)
+// CHECK:STDOUT: !11 = !DILocation(line: 13, column: 3, scope: !7)

toolchain/driver/testdata/compile/optimize/fail_clang_forward_optimize_size.carbon

@@ -0,0 +1,16 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// ARGS: compile --optimize=size %s -- -###
+//
+// SET-CAPTURE-CONSOLE-OUTPUT
+// SET-CHECK-SUBSET
+// NOAUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/driver/testdata/compile/optimize/fail_clang_forward_optimize_size.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/compile/optimize/fail_clang_forward_optimize_size.carbon
+// CHECK:STDERR:  "{{.*}}/toolchain/install/prefix_root/lib/carbon/../../lib/carbon/llvm/bin/clang" "-cc1" {{.*}} "-Oz" {{.*}}
+
+// --- fail_foo.carbon

toolchain/driver/testdata/compile/optimize/fail_clang_forward_optimize_speed.carbon

@@ -0,0 +1,16 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// ARGS: compile --optimize=speed %s -- -###
+//
+// SET-CAPTURE-CONSOLE-OUTPUT
+// SET-CHECK-SUBSET
+// NOAUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/driver/testdata/compile/optimize/fail_clang_forward_optimize_speed.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/compile/optimize/fail_clang_forward_optimize_speed.carbon
+// CHECK:STDERR:  "{{.*}}/toolchain/install/prefix_root/lib/carbon/../../lib/carbon/llvm/bin/clang" "-cc1" {{.*}} "-O3" {{.*}}
+
+// --- fail_foo.carbon

toolchain/driver/testdata/compile/optimize/fail_clang_no_optimize_arg.carbon

@@ -0,0 +1,16 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// ARGS: compile %s -- -###
+//
+// SET-CAPTURE-CONSOLE-OUTPUT
+// SET-CHECK-SUBSET
+// NOAUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/driver/testdata/compile/optimize/fail_clang_no_optimize_arg.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/compile/optimize/fail_clang_no_optimize_arg.carbon
+// CHECK:STDERR:  "{{.*}}/toolchain/install/prefix_root/lib/carbon/../../lib/carbon/llvm/bin/clang" "-cc1" {{.*}} "-O1" {{.*}}
+
+// --- fail_foo.carbon

toolchain/driver/testdata/compile/optimize/fail_clang_override_optimize_arg.carbon

@@ -0,0 +1,16 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// ARGS: compile --optimize=speed --clang-arg=-O1 %s -- -###
+//
+// SET-CAPTURE-CONSOLE-OUTPUT
+// SET-CHECK-SUBSET
+// NOAUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/driver/testdata/compile/optimize/fail_clang_override_optimize_arg.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/compile/optimize/fail_clang_override_optimize_arg.carbon
+// CHECK:STDERR:  "{{.*}}/toolchain/install/prefix_root/lib/carbon/../../lib/carbon/llvm/bin/clang" "-cc1" {{.*}} "-O1" {{.*}}
+
+// --- fail_foo.carbon

toolchain/driver/testdata/compile/optimize/optimize_debug.carbon

@@ -0,0 +1,117 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// ARGS: compile --optimize=debug foo.carbon --target=x86_64-unknown-linux-gnu --phase=optimize --dump-llvm-ir --exclude-dump-file-prefix=%{core}
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/driver/testdata/compile/optimize/optimize_debug.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/compile/optimize/optimize_debug.carbon
+
+// --- foo.carbon
+
+import Core library "range";
+
+fn Rand() -> i32;
+
+fn NoInlineWithOz() -> i32 {
+  return Rand() + Rand();
+}
+
+fn CallNoInlineWithOptSize() -> i32 {
+  // Should not be inlined with --optimize=size, because the body is larger than the call.
+  return NoInlineWithOz();
+}
+
+fn VectorizedWithOptSpeed(a: array(i32, 65536)*) {
+  // Should be vectorized with --optimize=speed, but not in other modes.
+  var n: i32 = 0;
+  while (n < 65536) {
+    (*a)[n] *= 2;
+    ++n;
+  }
+}
+
+// CHECK:STDOUT: ; ModuleID = 'foo.carbon'
+// CHECK:STDOUT: source_filename = "foo.carbon"
+// CHECK:STDOUT: target triple = "x86_64-unknown-linux-gnu"
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare i32 @_CRand.Main() local_unnamed_addr
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CNoInlineWithOz.Main() local_unnamed_addr #0 !dbg !4 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %Rand.call.loc7_15 = tail call i32 @_CRand.Main() #0, !dbg !7
+// CHECK:STDOUT:   %Rand.call.loc7_24 = tail call i32 @_CRand.Main() #0, !dbg !8
+// CHECK:STDOUT:   %Int.as.AddWith.impl.Op.call = add i32 %Rand.call.loc7_24, %Rand.call.loc7_15, !dbg !7
+// CHECK:STDOUT:   ret i32 %Int.as.AddWith.impl.Op.call, !dbg !9
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CCallNoInlineWithOptSize.Main() local_unnamed_addr #0 !dbg !10 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %Rand.call.loc7_15.i = tail call i32 @_CRand.Main() #0, !dbg !11
+// CHECK:STDOUT:   %Rand.call.loc7_24.i = tail call i32 @_CRand.Main() #0, !dbg !13
+// CHECK:STDOUT:   %Int.as.AddWith.impl.Op.call.i = add i32 %Rand.call.loc7_24.i, %Rand.call.loc7_15.i, !dbg !11
+// CHECK:STDOUT:   ret i32 %Int.as.AddWith.impl.Op.call.i, !dbg !14
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nofree norecurse nosync nounwind memory(argmem: readwrite)
+// CHECK:STDOUT: define void @_CVectorizedWithOptSpeed.Main(ptr captures(none) %a) local_unnamed_addr #1 !dbg !15 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   br label %while.body, !dbg !16
+// CHECK:STDOUT:
+// CHECK:STDOUT: while.body:                                       ; preds = %entry, %while.body
+// CHECK:STDOUT:   %n.var.03 = phi i32 [ 0, %entry ], [ %1, %while.body ]
+// CHECK:STDOUT:   %0 = zext nneg i32 %n.var.03 to i64, !dbg !17
+// CHECK:STDOUT:   %.loc19_11.array.index = getelementptr inbounds nuw i32, ptr %a, i64 %0, !dbg !17
+// CHECK:STDOUT:   %Int.as.MulAssignWith.impl.Op.call = load i32, ptr %.loc19_11.array.index, align 4, !dbg !17
+// CHECK:STDOUT:   %Int.as.MulAssignWith.impl.Op.call1 = shl i32 %Int.as.MulAssignWith.impl.Op.call, 1, !dbg !17
+// CHECK:STDOUT:   store i32 %Int.as.MulAssignWith.impl.Op.call1, ptr %.loc19_11.array.index, align 4, !dbg !17
+// CHECK:STDOUT:   %1 = add nuw nsw i32 %n.var.03, 1, !dbg !18
+// CHECK:STDOUT:   %Int.as.OrderedWith.impl.Less.call = icmp samesign ult i32 %n.var.03, 65535, !dbg !24
+// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Less.call, label %while.body, label %while.done, !dbg !16
+// CHECK:STDOUT:
+// CHECK:STDOUT: while.done:                                       ; preds = %while.body
+// CHECK:STDOUT:   ret void, !dbg !25
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; uselistorder directives
+// CHECK:STDOUT:   uselistorder label %while.body, { 1, 0 }
+// CHECK:STDOUT:   uselistorder i32 %n.var.03, { 0, 2, 1 }
+// CHECK:STDOUT:   uselistorder ptr %.loc19_11.array.index, { 1, 0 }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nofree norecurse nosync nounwind memory(argmem: readwrite) }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
+// CHECK:STDOUT: !llvm.dbg.cu = !{!2}
+// CHECK:STDOUT:
+// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
+// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !3 = !DIFile(filename: "foo.carbon", directory: "")
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "NoInlineWithOz", linkageName: "_CNoInlineWithOz.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
+// CHECK:STDOUT: !6 = !{}
+// CHECK:STDOUT: !7 = !DILocation(line: 7, column: 10, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 7, column: 19, scope: !4)
+// CHECK:STDOUT: !9 = !DILocation(line: 7, column: 3, scope: !4)
+// CHECK:STDOUT: !10 = distinct !DISubprogram(name: "CallNoInlineWithOptSize", linkageName: "_CCallNoInlineWithOptSize.Main", scope: null, file: !3, line: 10, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !11 = !DILocation(line: 7, column: 10, scope: !4, inlinedAt: !12)
+// CHECK:STDOUT: !12 = distinct !DILocation(line: 12, column: 10, scope: !10)
+// CHECK:STDOUT: !13 = !DILocation(line: 7, column: 19, scope: !4, inlinedAt: !12)
+// CHECK:STDOUT: !14 = !DILocation(line: 12, column: 3, scope: !10)
+// CHECK:STDOUT: !15 = distinct !DISubprogram(name: "VectorizedWithOptSpeed", linkageName: "_CVectorizedWithOptSpeed.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !16 = !DILocation(line: 18, column: 9, scope: !15)
+// CHECK:STDOUT: !17 = !DILocation(line: 19, column: 5, scope: !15)
+// CHECK:STDOUT: !18 = !DILocation(line: 275, column: 3, scope: !19, inlinedAt: !21)
+// CHECK:STDOUT: !19 = distinct !DISubprogram(name: "Op", linkageName: "_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e", scope: null, file: !20, line: 275, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !20 = !DIFile(filename: "{{.*}}/prelude/types/int.carbon", directory: "")
+// CHECK:STDOUT: !21 = distinct !DILocation(line: 341, column: 5, scope: !22, inlinedAt: !23)
+// CHECK:STDOUT: !22 = distinct !DISubprogram(name: "Op", linkageName: "_COp.Int.Core:Inc.Core.be1e879c1ad406d8", scope: null, file: !20, line: 339, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !23 = distinct !DILocation(line: 20, column: 5, scope: !15)
+// CHECK:STDOUT: !24 = !DILocation(line: 18, column: 10, scope: !15)
+// CHECK:STDOUT: !25 = !DILocation(line: 15, column: 1, scope: !15)

toolchain/driver/testdata/compile/optimize/optimize_default.carbon

@@ -0,0 +1,117 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// ARGS: compile foo.carbon --target=x86_64-unknown-linux-gnu --phase=optimize --dump-llvm-ir --exclude-dump-file-prefix=%{core}
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/driver/testdata/compile/optimize/optimize_default.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/compile/optimize/optimize_default.carbon
+
+// --- foo.carbon
+
+import Core library "range";
+
+fn Rand() -> i32;
+
+fn NoInlineWithOz() -> i32 {
+  return Rand() + Rand();
+}
+
+fn CallNoInlineWithOptSize() -> i32 {
+  // Should not be inlined with --optimize=size, because the body is larger than the call.
+  return NoInlineWithOz();
+}
+
+fn VectorizedWithOptSpeed(a: array(i32, 65536)*) {
+  // Should be vectorized with --optimize=speed, but not in other modes.
+  var n: i32 = 0;
+  while (n < 65536) {
+    (*a)[n] *= 2;
+    ++n;
+  }
+}
+
+// CHECK:STDOUT: ; ModuleID = 'foo.carbon'
+// CHECK:STDOUT: source_filename = "foo.carbon"
+// CHECK:STDOUT: target triple = "x86_64-unknown-linux-gnu"
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare i32 @_CRand.Main() local_unnamed_addr
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CNoInlineWithOz.Main() local_unnamed_addr #0 !dbg !4 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %Rand.call.loc7_15 = tail call i32 @_CRand.Main() #0, !dbg !7
+// CHECK:STDOUT:   %Rand.call.loc7_24 = tail call i32 @_CRand.Main() #0, !dbg !8
+// CHECK:STDOUT:   %Int.as.AddWith.impl.Op.call = add i32 %Rand.call.loc7_24, %Rand.call.loc7_15, !dbg !7
+// CHECK:STDOUT:   ret i32 %Int.as.AddWith.impl.Op.call, !dbg !9
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CCallNoInlineWithOptSize.Main() local_unnamed_addr #0 !dbg !10 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %Rand.call.loc7_15.i = tail call i32 @_CRand.Main() #0, !dbg !11
+// CHECK:STDOUT:   %Rand.call.loc7_24.i = tail call i32 @_CRand.Main() #0, !dbg !13
+// CHECK:STDOUT:   %Int.as.AddWith.impl.Op.call.i = add i32 %Rand.call.loc7_24.i, %Rand.call.loc7_15.i, !dbg !11
+// CHECK:STDOUT:   ret i32 %Int.as.AddWith.impl.Op.call.i, !dbg !14
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nofree norecurse nosync nounwind memory(argmem: readwrite)
+// CHECK:STDOUT: define void @_CVectorizedWithOptSpeed.Main(ptr captures(none) %a) local_unnamed_addr #1 !dbg !15 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   br label %while.body, !dbg !16
+// CHECK:STDOUT:
+// CHECK:STDOUT: while.body:                                       ; preds = %entry, %while.body
+// CHECK:STDOUT:   %n.var.03 = phi i32 [ 0, %entry ], [ %1, %while.body ]
+// CHECK:STDOUT:   %0 = zext nneg i32 %n.var.03 to i64, !dbg !17
+// CHECK:STDOUT:   %.loc19_11.array.index = getelementptr inbounds nuw i32, ptr %a, i64 %0, !dbg !17
+// CHECK:STDOUT:   %Int.as.MulAssignWith.impl.Op.call = load i32, ptr %.loc19_11.array.index, align 4, !dbg !17
+// CHECK:STDOUT:   %Int.as.MulAssignWith.impl.Op.call1 = shl i32 %Int.as.MulAssignWith.impl.Op.call, 1, !dbg !17
+// CHECK:STDOUT:   store i32 %Int.as.MulAssignWith.impl.Op.call1, ptr %.loc19_11.array.index, align 4, !dbg !17
+// CHECK:STDOUT:   %1 = add nuw nsw i32 %n.var.03, 1, !dbg !18
+// CHECK:STDOUT:   %Int.as.OrderedWith.impl.Less.call = icmp samesign ult i32 %n.var.03, 65535, !dbg !24
+// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Less.call, label %while.body, label %while.done, !dbg !16
+// CHECK:STDOUT:
+// CHECK:STDOUT: while.done:                                       ; preds = %while.body
+// CHECK:STDOUT:   ret void, !dbg !25
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; uselistorder directives
+// CHECK:STDOUT:   uselistorder label %while.body, { 1, 0 }
+// CHECK:STDOUT:   uselistorder i32 %n.var.03, { 0, 2, 1 }
+// CHECK:STDOUT:   uselistorder ptr %.loc19_11.array.index, { 1, 0 }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nofree norecurse nosync nounwind memory(argmem: readwrite) }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
+// CHECK:STDOUT: !llvm.dbg.cu = !{!2}
+// CHECK:STDOUT:
+// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
+// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !3 = !DIFile(filename: "foo.carbon", directory: "")
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "NoInlineWithOz", linkageName: "_CNoInlineWithOz.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
+// CHECK:STDOUT: !6 = !{}
+// CHECK:STDOUT: !7 = !DILocation(line: 7, column: 10, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 7, column: 19, scope: !4)
+// CHECK:STDOUT: !9 = !DILocation(line: 7, column: 3, scope: !4)
+// CHECK:STDOUT: !10 = distinct !DISubprogram(name: "CallNoInlineWithOptSize", linkageName: "_CCallNoInlineWithOptSize.Main", scope: null, file: !3, line: 10, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !11 = !DILocation(line: 7, column: 10, scope: !4, inlinedAt: !12)
+// CHECK:STDOUT: !12 = distinct !DILocation(line: 12, column: 10, scope: !10)
+// CHECK:STDOUT: !13 = !DILocation(line: 7, column: 19, scope: !4, inlinedAt: !12)
+// CHECK:STDOUT: !14 = !DILocation(line: 12, column: 3, scope: !10)
+// CHECK:STDOUT: !15 = distinct !DISubprogram(name: "VectorizedWithOptSpeed", linkageName: "_CVectorizedWithOptSpeed.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !16 = !DILocation(line: 18, column: 9, scope: !15)
+// CHECK:STDOUT: !17 = !DILocation(line: 19, column: 5, scope: !15)
+// CHECK:STDOUT: !18 = !DILocation(line: 275, column: 3, scope: !19, inlinedAt: !21)
+// CHECK:STDOUT: !19 = distinct !DISubprogram(name: "Op", linkageName: "_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e", scope: null, file: !20, line: 275, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !20 = !DIFile(filename: "{{.*}}/prelude/types/int.carbon", directory: "")
+// CHECK:STDOUT: !21 = distinct !DILocation(line: 341, column: 5, scope: !22, inlinedAt: !23)
+// CHECK:STDOUT: !22 = distinct !DISubprogram(name: "Op", linkageName: "_COp.Int.Core:Inc.Core.be1e879c1ad406d8", scope: null, file: !20, line: 339, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !23 = distinct !DILocation(line: 20, column: 5, scope: !15)
+// CHECK:STDOUT: !24 = !DILocation(line: 18, column: 10, scope: !15)
+// CHECK:STDOUT: !25 = !DILocation(line: 15, column: 1, scope: !15)

toolchain/driver/testdata/compile/optimize/optimize_none.carbon

@@ -0,0 +1,145 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// ARGS: compile --optimize=none foo.carbon --target=x86_64-unknown-linux-gnu --phase=optimize --dump-llvm-ir --exclude-dump-file-prefix=%{core}
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/driver/testdata/compile/optimize/optimize_none.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/compile/optimize/optimize_none.carbon
+
+// --- foo.carbon
+
+import Core library "range";
+
+fn Rand() -> i32;
+
+fn NoInlineWithOz() -> i32 {
+  return Rand() + Rand();
+}
+
+fn CallNoInlineWithOptSize() -> i32 {
+  // Should not be inlined with --optimize=size, because the body is larger than the call.
+  return NoInlineWithOz();
+}
+
+fn VectorizedWithOptSpeed(a: array(i32, 65536)*) {
+  // Should be vectorized with --optimize=speed, but not in other modes.
+  var n: i32 = 0;
+  while (n < 65536) {
+    (*a)[n] *= 2;
+    ++n;
+  }
+}
+
+// CHECK:STDOUT: ; ModuleID = 'foo.carbon'
+// CHECK:STDOUT: source_filename = "foo.carbon"
+// CHECK:STDOUT: target triple = "x86_64-unknown-linux-gnu"
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare i32 @_CRand.Main()
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: noinline nounwind optnone
+// CHECK:STDOUT: define i32 @_CNoInlineWithOz.Main() #0 !dbg !4 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %Rand.call.loc7_15 = call i32 @_CRand.Main(), !dbg !7
+// CHECK:STDOUT:   %Rand.call.loc7_24 = call i32 @_CRand.Main(), !dbg !8
+// CHECK:STDOUT:   %Int.as.AddWith.impl.Op.call = add i32 %Rand.call.loc7_15, %Rand.call.loc7_24, !dbg !7
+// CHECK:STDOUT:   ret i32 %Int.as.AddWith.impl.Op.call, !dbg !9
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: noinline nounwind optnone
+// CHECK:STDOUT: define i32 @_CCallNoInlineWithOptSize.Main() #0 !dbg !10 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %NoInlineWithOz.call = call i32 @_CNoInlineWithOz.Main(), !dbg !11
+// CHECK:STDOUT:   ret i32 %NoInlineWithOz.call, !dbg !12
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: noinline nounwind optnone
+// CHECK:STDOUT: define void @_CVectorizedWithOptSpeed.Main(ptr %a) #0 !dbg !13 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %n.var = alloca i32, align 4, !dbg !14
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %n.var), !dbg !14
+// CHECK:STDOUT:   store i32 0, ptr %n.var, align 4, !dbg !14
+// CHECK:STDOUT:   br label %while.cond, !dbg !15
+// CHECK:STDOUT:
+// CHECK:STDOUT: while.cond:                                       ; preds = %while.body, %entry
+// CHECK:STDOUT:   %.loc18_10 = load i32, ptr %n.var, align 4, !dbg !16
+// CHECK:STDOUT:   %Int.as.OrderedWith.impl.Less.call = icmp slt i32 %.loc18_10, 65536, !dbg !16
+// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Less.call, label %while.body, label %while.done, !dbg !15
+// CHECK:STDOUT:
+// CHECK:STDOUT: while.body:                                       ; preds = %while.cond
+// CHECK:STDOUT:   %.loc19_10 = load i32, ptr %n.var, align 4, !dbg !17
+// CHECK:STDOUT:   %.loc19_11.array.index = getelementptr inbounds [65536 x i32], ptr %a, i32 0, i32 %.loc19_10, !dbg !18
+// CHECK:STDOUT:   %Int.as.MulAssignWith.impl.Op.call = load i32, ptr %.loc19_11.array.index, align 4, !dbg !18
+// CHECK:STDOUT:   %Int.as.MulAssignWith.impl.Op.call1 = mul i32 %Int.as.MulAssignWith.impl.Op.call, 2, !dbg !18
+// CHECK:STDOUT:   store i32 %Int.as.MulAssignWith.impl.Op.call1, ptr %.loc19_11.array.index, align 4, !dbg !18
+// CHECK:STDOUT:   call void @"_COp.Int.Core:Inc.Core.be1e879c1ad406d8"(ptr %n.var), !dbg !19
+// CHECK:STDOUT:   br label %while.cond, !dbg !20
+// CHECK:STDOUT:
+// CHECK:STDOUT: while.done:                                       ; preds = %while.cond
+// CHECK:STDOUT:   ret void, !dbg !21
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: noinline nounwind optnone
+// CHECK:STDOUT: define linkonce_odr void @"_COp.Int.Core:Inc.Core.be1e879c1ad406d8"(ptr %self) #0 !dbg !22 {
+// CHECK:STDOUT:   call void @"_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e"(ptr %self, i32 1), !dbg !24
+// CHECK:STDOUT:   ret void, !dbg !25
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: noinline nounwind optnone
+// CHECK:STDOUT: define linkonce_odr void @"_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e"(ptr %self, i32 %other) #0 !dbg !26 {
+// CHECK:STDOUT:   %1 = call i32 @"_CConvert.225258f1a45e9386:ImplicitAs.Core.5450dc8e8b8e0899"(i32 %other), !dbg !27
+// CHECK:STDOUT:   %2 = load i32, ptr %self, align 4, !dbg !28
+// CHECK:STDOUT:   %3 = add i32 %2, %1, !dbg !28
+// CHECK:STDOUT:   store i32 %3, ptr %self, align 4, !dbg !28
+// CHECK:STDOUT:   ret void, !dbg !28
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: noinline nounwind optnone
+// CHECK:STDOUT: define linkonce_odr i32 @"_CConvert.225258f1a45e9386:ImplicitAs.Core.5450dc8e8b8e0899"(i32 %self) #0 !dbg !29 {
+// CHECK:STDOUT:   ret i32 %self, !dbg !31
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { noinline nounwind optnone }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
+// CHECK:STDOUT: !llvm.dbg.cu = !{!2}
+// CHECK:STDOUT:
+// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
+// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !3 = !DIFile(filename: "foo.carbon", directory: "")
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "NoInlineWithOz", linkageName: "_CNoInlineWithOz.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
+// CHECK:STDOUT: !6 = !{}
+// CHECK:STDOUT: !7 = !DILocation(line: 7, column: 10, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 7, column: 19, scope: !4)
+// CHECK:STDOUT: !9 = !DILocation(line: 7, column: 3, scope: !4)
+// CHECK:STDOUT: !10 = distinct !DISubprogram(name: "CallNoInlineWithOptSize", linkageName: "_CCallNoInlineWithOptSize.Main", scope: null, file: !3, line: 10, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !11 = !DILocation(line: 12, column: 10, scope: !10)
+// CHECK:STDOUT: !12 = !DILocation(line: 12, column: 3, scope: !10)
+// CHECK:STDOUT: !13 = distinct !DISubprogram(name: "VectorizedWithOptSpeed", linkageName: "_CVectorizedWithOptSpeed.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !14 = !DILocation(line: 17, column: 3, scope: !13)
+// CHECK:STDOUT: !15 = !DILocation(line: 18, column: 9, scope: !13)
+// CHECK:STDOUT: !16 = !DILocation(line: 18, column: 10, scope: !13)
+// CHECK:STDOUT: !17 = !DILocation(line: 19, column: 10, scope: !13)
+// CHECK:STDOUT: !18 = !DILocation(line: 19, column: 5, scope: !13)
+// CHECK:STDOUT: !19 = !DILocation(line: 20, column: 5, scope: !13)
+// CHECK:STDOUT: !20 = !DILocation(line: 18, column: 3, scope: !13)
+// CHECK:STDOUT: !21 = !DILocation(line: 15, column: 1, scope: !13)
+// CHECK:STDOUT: !22 = distinct !DISubprogram(name: "Op", linkageName: "_COp.Int.Core:Inc.Core.be1e879c1ad406d8", scope: null, file: !23, line: 339, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !23 = !DIFile(filename: "{{.*}}/prelude/types/int.carbon", directory: "")
+// CHECK:STDOUT: !24 = !DILocation(line: 341, column: 5, scope: !22)
+// CHECK:STDOUT: !25 = !DILocation(line: 339, column: 3, scope: !22)
+// CHECK:STDOUT: !26 = distinct !DISubprogram(name: "Op", linkageName: "_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e", scope: null, file: !23, line: 275, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !27 = !DILocation(line: 4294967295, scope: !26)
+// CHECK:STDOUT: !28 = !DILocation(line: 275, column: 3, scope: !26)
+// CHECK:STDOUT: !29 = distinct !DISubprogram(name: "Convert", linkageName: "_CConvert.225258f1a45e9386:ImplicitAs.Core.5450dc8e8b8e0899", scope: null, file: !30, line: 24, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !30 = !DIFile(filename: "{{.*}}/prelude/operators/as.carbon", directory: "")
+// CHECK:STDOUT: !31 = !DILocation(line: 24, column: 38, scope: !29)

toolchain/driver/testdata/compile/optimize/optimize_size.carbon

@@ -0,0 +1,145 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// ARGS: compile --optimize=size foo.carbon --target=x86_64-unknown-linux-gnu --phase=lower --dump-llvm-ir --exclude-dump-file-prefix=%{core}
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/driver/testdata/compile/optimize/optimize_size.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/compile/optimize/optimize_size.carbon
+
+// --- foo.carbon
+
+import Core library "range";
+
+fn Rand() -> i32;
+
+fn NoInlineWithOz() -> i32 {
+  return Rand() + Rand();
+}
+
+fn CallNoInlineWithOptSize() -> i32 {
+  // Should not be inlined with --optimize=size, because the body is larger than the call.
+  return NoInlineWithOz();
+}
+
+fn VectorizedWithOptSpeed(a: array(i32, 65536)*) {
+  // Should be vectorized with --optimize=speed, but not in other modes.
+  var n: i32 = 0;
+  while (n < 65536) {
+    (*a)[n] *= 2;
+    ++n;
+  }
+}
+
+// CHECK:STDOUT: ; ModuleID = 'foo.carbon'
+// CHECK:STDOUT: source_filename = "foo.carbon"
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare i32 @_CRand.Main()
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: minsize nounwind optsize
+// CHECK:STDOUT: define i32 @_CNoInlineWithOz.Main() #0 !dbg !4 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %Rand.call.loc7_15 = call i32 @_CRand.Main(), !dbg !7
+// CHECK:STDOUT:   %Rand.call.loc7_24 = call i32 @_CRand.Main(), !dbg !8
+// CHECK:STDOUT:   %Int.as.AddWith.impl.Op.call = add i32 %Rand.call.loc7_15, %Rand.call.loc7_24, !dbg !7
+// CHECK:STDOUT:   ret i32 %Int.as.AddWith.impl.Op.call, !dbg !9
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: minsize nounwind optsize
+// CHECK:STDOUT: define i32 @_CCallNoInlineWithOptSize.Main() #0 !dbg !10 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %NoInlineWithOz.call = call i32 @_CNoInlineWithOz.Main(), !dbg !11
+// CHECK:STDOUT:   ret i32 %NoInlineWithOz.call, !dbg !12
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: minsize nounwind optsize
+// CHECK:STDOUT: define void @_CVectorizedWithOptSpeed.Main(ptr %a) #0 !dbg !13 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %n.var = alloca i32, align 4, !dbg !14
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %n.var), !dbg !14
+// CHECK:STDOUT:   store i32 0, ptr %n.var, align 4, !dbg !14
+// CHECK:STDOUT:   br label %while.cond, !dbg !15
+// CHECK:STDOUT:
+// CHECK:STDOUT: while.cond:                                       ; preds = %while.body, %entry
+// CHECK:STDOUT:   %.loc18_10 = load i32, ptr %n.var, align 4, !dbg !16
+// CHECK:STDOUT:   %Int.as.OrderedWith.impl.Less.call = icmp slt i32 %.loc18_10, 65536, !dbg !16
+// CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Less.call, label %while.body, label %while.done, !dbg !15
+// CHECK:STDOUT:
+// CHECK:STDOUT: while.body:                                       ; preds = %while.cond
+// CHECK:STDOUT:   %.loc19_10 = load i32, ptr %n.var, align 4, !dbg !17
+// CHECK:STDOUT:   %.loc19_11.array.index = getelementptr inbounds [65536 x i32], ptr %a, i32 0, i32 %.loc19_10, !dbg !18
+// CHECK:STDOUT:   %Int.as.MulAssignWith.impl.Op.call = load i32, ptr %.loc19_11.array.index, align 4, !dbg !18
+// CHECK:STDOUT:   %Int.as.MulAssignWith.impl.Op.call1 = mul i32 %Int.as.MulAssignWith.impl.Op.call, 2, !dbg !18
+// CHECK:STDOUT:   store i32 %Int.as.MulAssignWith.impl.Op.call1, ptr %.loc19_11.array.index, align 4, !dbg !18
+// CHECK:STDOUT:   call void @"_COp.Int.Core:Inc.Core.be1e879c1ad406d8"(ptr %n.var), !dbg !19
+// CHECK:STDOUT:   br label %while.cond, !dbg !20
+// CHECK:STDOUT:
+// CHECK:STDOUT: while.done:                                       ; preds = %while.cond
+// CHECK:STDOUT:   ret void, !dbg !21
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: minsize nounwind optsize
+// CHECK:STDOUT: define linkonce_odr void @"_COp.Int.Core:Inc.Core.be1e879c1ad406d8"(ptr %self) #0 !dbg !22 {
+// CHECK:STDOUT:   call void @"_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e"(ptr %self, i32 1), !dbg !24
+// CHECK:STDOUT:   ret void, !dbg !25
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: alwaysinline minsize nounwind optsize
+// CHECK:STDOUT: define linkonce_odr void @"_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e"(ptr %self, i32 %other) #2 !dbg !26 {
+// CHECK:STDOUT:   %1 = call i32 @"_CConvert.225258f1a45e9386:ImplicitAs.Core.5450dc8e8b8e0899"(i32 %other), !dbg !27
+// CHECK:STDOUT:   %2 = load i32, ptr %self, align 4, !dbg !28
+// CHECK:STDOUT:   %3 = add i32 %2, %1, !dbg !28
+// CHECK:STDOUT:   store i32 %3, ptr %self, align 4, !dbg !28
+// CHECK:STDOUT:   ret void, !dbg !28
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: minsize nounwind optsize
+// CHECK:STDOUT: define linkonce_odr i32 @"_CConvert.225258f1a45e9386:ImplicitAs.Core.5450dc8e8b8e0899"(i32 %self) #0 !dbg !29 {
+// CHECK:STDOUT:   ret i32 %self, !dbg !31
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { minsize nounwind optsize }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { alwaysinline minsize nounwind optsize }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
+// CHECK:STDOUT: !llvm.dbg.cu = !{!2}
+// CHECK:STDOUT:
+// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
+// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !3 = !DIFile(filename: "foo.carbon", directory: "")
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "NoInlineWithOz", linkageName: "_CNoInlineWithOz.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
+// CHECK:STDOUT: !6 = !{}
+// CHECK:STDOUT: !7 = !DILocation(line: 7, column: 10, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 7, column: 19, scope: !4)
+// CHECK:STDOUT: !9 = !DILocation(line: 7, column: 3, scope: !4)
+// CHECK:STDOUT: !10 = distinct !DISubprogram(name: "CallNoInlineWithOptSize", linkageName: "_CCallNoInlineWithOptSize.Main", scope: null, file: !3, line: 10, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !11 = !DILocation(line: 12, column: 10, scope: !10)
+// CHECK:STDOUT: !12 = !DILocation(line: 12, column: 3, scope: !10)
+// CHECK:STDOUT: !13 = distinct !DISubprogram(name: "VectorizedWithOptSpeed", linkageName: "_CVectorizedWithOptSpeed.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !14 = !DILocation(line: 17, column: 3, scope: !13)
+// CHECK:STDOUT: !15 = !DILocation(line: 18, column: 9, scope: !13)
+// CHECK:STDOUT: !16 = !DILocation(line: 18, column: 10, scope: !13)
+// CHECK:STDOUT: !17 = !DILocation(line: 19, column: 10, scope: !13)
+// CHECK:STDOUT: !18 = !DILocation(line: 19, column: 5, scope: !13)
+// CHECK:STDOUT: !19 = !DILocation(line: 20, column: 5, scope: !13)
+// CHECK:STDOUT: !20 = !DILocation(line: 18, column: 3, scope: !13)
+// CHECK:STDOUT: !21 = !DILocation(line: 15, column: 1, scope: !13)
+// CHECK:STDOUT: !22 = distinct !DISubprogram(name: "Op", linkageName: "_COp.Int.Core:Inc.Core.be1e879c1ad406d8", scope: null, file: !23, line: 339, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !23 = !DIFile(filename: "{{.*}}/prelude/types/int.carbon", directory: "")
+// CHECK:STDOUT: !24 = !DILocation(line: 341, column: 5, scope: !22)
+// CHECK:STDOUT: !25 = !DILocation(line: 339, column: 3, scope: !22)
+// CHECK:STDOUT: !26 = distinct !DISubprogram(name: "Op", linkageName: "_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e", scope: null, file: !23, line: 275, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !27 = !DILocation(line: 4294967295, scope: !26)
+// CHECK:STDOUT: !28 = !DILocation(line: 275, column: 3, scope: !26)
+// CHECK:STDOUT: !29 = distinct !DISubprogram(name: "Convert", linkageName: "_CConvert.225258f1a45e9386:ImplicitAs.Core.5450dc8e8b8e0899", scope: null, file: !30, line: 24, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !30 = !DIFile(filename: "{{.*}}/prelude/operators/as.carbon", directory: "")
+// CHECK:STDOUT: !31 = !DILocation(line: 24, column: 38, scope: !29)

toolchain/driver/testdata/compile/optimize/optimize_speed.carbon

@@ -0,0 +1,135 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// ARGS: compile --optimize=speed foo.carbon --target=x86_64-unknown-linux-gnu --phase=optimize --dump-llvm-ir --exclude-dump-file-prefix=%{core}
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/driver/testdata/compile/optimize/optimize_speed.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/compile/optimize/optimize_speed.carbon
+
+// --- foo.carbon
+
+import Core library "range";
+
+fn Rand() -> i32;
+
+fn NoInlineWithOz() -> i32 {
+  return Rand() + Rand();
+}
+
+fn CallNoInlineWithOptSize() -> i32 {
+  // Should not be inlined with --optimize=size, because the body is larger than the call.
+  return NoInlineWithOz();
+}
+
+fn VectorizedWithOptSpeed(a: array(i32, 65536)*) {
+  // Should be vectorized with --optimize=speed, but not in other modes.
+  var n: i32 = 0;
+  while (n < 65536) {
+    (*a)[n] *= 2;
+    ++n;
+  }
+}
+
+// CHECK:STDOUT: ; ModuleID = 'foo.carbon'
+// CHECK:STDOUT: source_filename = "foo.carbon"
+// CHECK:STDOUT: target triple = "x86_64-unknown-linux-gnu"
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare i32 @_CRand.Main() local_unnamed_addr
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CNoInlineWithOz.Main() local_unnamed_addr #0 !dbg !4 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %Rand.call.loc7_15 = tail call i32 @_CRand.Main() #0, !dbg !7
+// CHECK:STDOUT:   %Rand.call.loc7_24 = tail call i32 @_CRand.Main() #0, !dbg !8
+// CHECK:STDOUT:   %Int.as.AddWith.impl.Op.call = add i32 %Rand.call.loc7_24, %Rand.call.loc7_15, !dbg !7
+// CHECK:STDOUT:   ret i32 %Int.as.AddWith.impl.Op.call, !dbg !9
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CCallNoInlineWithOptSize.Main() local_unnamed_addr #0 !dbg !10 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %Rand.call.loc7_15.i = tail call i32 @_CRand.Main() #0, !dbg !11
+// CHECK:STDOUT:   %Rand.call.loc7_24.i = tail call i32 @_CRand.Main() #0, !dbg !13
+// CHECK:STDOUT:   %Int.as.AddWith.impl.Op.call.i = add i32 %Rand.call.loc7_24.i, %Rand.call.loc7_15.i, !dbg !11
+// CHECK:STDOUT:   ret i32 %Int.as.AddWith.impl.Op.call.i, !dbg !14
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nofree norecurse nosync nounwind memory(argmem: readwrite)
+// CHECK:STDOUT: define void @_CVectorizedWithOptSpeed.Main(ptr captures(none) %a) local_unnamed_addr #1 !dbg !15 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   br label %vector.body, !dbg !16
+// CHECK:STDOUT:
+// CHECK:STDOUT: vector.body:                                      ; preds = %vector.body, %entry
+// CHECK:STDOUT:   %index = phi i32 [ 0, %entry ], [ %index.next.1, %vector.body ], !dbg !17
+// CHECK:STDOUT:   %0 = zext nneg i32 %index to i64, !dbg !23
+// CHECK:STDOUT:   %1 = getelementptr inbounds nuw i32, ptr %a, i64 %0, !dbg !23
+// CHECK:STDOUT:   %2 = getelementptr inbounds nuw i8, ptr %1, i64 16, !dbg !23
+// CHECK:STDOUT:   %wide.load = load <4 x i32>, ptr %1, align 4, !dbg !23
+// CHECK:STDOUT:   %wide.load4 = load <4 x i32>, ptr %2, align 4, !dbg !23
+// CHECK:STDOUT:   %3 = shl <4 x i32> %wide.load, splat (i32 1), !dbg !23
+// CHECK:STDOUT:   %4 = shl <4 x i32> %wide.load4, splat (i32 1), !dbg !23
+// CHECK:STDOUT:   store <4 x i32> %3, ptr %1, align 4, !dbg !23
+// CHECK:STDOUT:   store <4 x i32> %4, ptr %2, align 4, !dbg !23
+// CHECK:STDOUT:   %5 = zext nneg i32 %index to i64, !dbg !23
+// CHECK:STDOUT:   %6 = getelementptr inbounds nuw i32, ptr %a, i64 %5, !dbg !23
+// CHECK:STDOUT:   %7 = getelementptr inbounds nuw i8, ptr %6, i64 32, !dbg !23
+// CHECK:STDOUT:   %8 = getelementptr inbounds nuw i8, ptr %6, i64 48, !dbg !23
+// CHECK:STDOUT:   %wide.load.1 = load <4 x i32>, ptr %7, align 4, !dbg !23
+// CHECK:STDOUT:   %wide.load4.1 = load <4 x i32>, ptr %8, align 4, !dbg !23
+// CHECK:STDOUT:   %9 = shl <4 x i32> %wide.load.1, splat (i32 1), !dbg !23
+// CHECK:STDOUT:   %10 = shl <4 x i32> %wide.load4.1, splat (i32 1), !dbg !23
+// CHECK:STDOUT:   store <4 x i32> %9, ptr %7, align 4, !dbg !23
+// CHECK:STDOUT:   store <4 x i32> %10, ptr %8, align 4, !dbg !23
+// CHECK:STDOUT:   %index.next.1 = add nuw nsw i32 %index, 16, !dbg !17
+// CHECK:STDOUT:   %11 = icmp eq i32 %index.next.1, 65536, !dbg !16
+// CHECK:STDOUT:   br i1 %11, label %while.done, label %vector.body, !dbg !16, !llvm.loop !24
+// CHECK:STDOUT:
+// CHECK:STDOUT: while.done:                                       ; preds = %vector.body
+// CHECK:STDOUT:   ret void, !dbg !27
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; uselistorder directives
+// CHECK:STDOUT:   uselistorder i32 %index, { 1, 0, 2 }
+// CHECK:STDOUT:   uselistorder ptr %1, { 1, 2, 0 }
+// CHECK:STDOUT:   uselistorder ptr %2, { 1, 0 }
+// CHECK:STDOUT:   uselistorder ptr %8, { 1, 0 }
+// CHECK:STDOUT:   uselistorder i32 %index.next.1, { 1, 0 }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nofree norecurse nosync nounwind memory(argmem: readwrite) }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
+// CHECK:STDOUT: !llvm.dbg.cu = !{!2}
+// CHECK:STDOUT:
+// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
+// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !3 = !DIFile(filename: "foo.carbon", directory: "")
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "NoInlineWithOz", linkageName: "_CNoInlineWithOz.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
+// CHECK:STDOUT: !6 = !{}
+// CHECK:STDOUT: !7 = !DILocation(line: 7, column: 10, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 7, column: 19, scope: !4)
+// CHECK:STDOUT: !9 = !DILocation(line: 7, column: 3, scope: !4)
+// CHECK:STDOUT: !10 = distinct !DISubprogram(name: "CallNoInlineWithOptSize", linkageName: "_CCallNoInlineWithOptSize.Main", scope: null, file: !3, line: 10, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !11 = !DILocation(line: 7, column: 10, scope: !4, inlinedAt: !12)
+// CHECK:STDOUT: !12 = distinct !DILocation(line: 12, column: 10, scope: !10)
+// CHECK:STDOUT: !13 = !DILocation(line: 7, column: 19, scope: !4, inlinedAt: !12)
+// CHECK:STDOUT: !14 = !DILocation(line: 12, column: 3, scope: !10)
+// CHECK:STDOUT: !15 = distinct !DISubprogram(name: "VectorizedWithOptSpeed", linkageName: "_CVectorizedWithOptSpeed.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !16 = !DILocation(line: 18, column: 9, scope: !15)
+// CHECK:STDOUT: !17 = !DILocation(line: 275, column: 3, scope: !18, inlinedAt: !20)
+// CHECK:STDOUT: !18 = distinct !DISubprogram(name: "Op", linkageName: "_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e", scope: null, file: !19, line: 275, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !19 = !DIFile(filename: "{{.*}}/prelude/types/int.carbon", directory: "")
+// CHECK:STDOUT: !20 = distinct !DILocation(line: 341, column: 5, scope: !21, inlinedAt: !22)
+// CHECK:STDOUT: !21 = distinct !DISubprogram(name: "Op", linkageName: "_COp.Int.Core:Inc.Core.be1e879c1ad406d8", scope: null, file: !19, line: 339, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !22 = distinct !DILocation(line: 20, column: 5, scope: !15)
+// CHECK:STDOUT: !23 = !DILocation(line: 19, column: 5, scope: !15)
+// CHECK:STDOUT: !24 = distinct !{!24, !25, !26}
+// CHECK:STDOUT: !25 = !{!"llvm.loop.isvectorized", i32 1}
+// CHECK:STDOUT: !26 = !{!"llvm.loop.unroll.runtime.disable"}
+// CHECK:STDOUT: !27 = !DILocation(line: 15, column: 1, scope: !15)

toolchain/lower/BUILD

@@ -11,17 +11,27 @@ filegroup(
     srcs = glob(["testdata/**/*.carbon"]),
 )
 
+cc_library(
+    name = "options",
+    hdrs = ["options.h"],
+    deps = [
+        "@llvm-project//llvm:Support",
+    ],
+)
+
 cc_library(
     name = "lower",
     srcs = ["lower.cpp"],
     hdrs = ["lower.h"],
     deps = [
         ":context",
+        ":options",
         "//common:vlog",
         "//toolchain/parse:tree",
         "//toolchain/sem_ir:file",
         "//toolchain/sem_ir:inst_namer",
         "@llvm-project//llvm:Core",
+        "@llvm-project//llvm:Passes",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -51,6 +61,7 @@ cc_library(
         "specific_coalescer.h",
     ],
     deps = [
+        ":options",
         "//common:check",
         "//common:growing_range",
         "//common:map",
@@ -75,6 +86,7 @@ cc_library(
         "@llvm-project//clang:lex",
         "@llvm-project//llvm:Core",
         "@llvm-project//llvm:Linker",
+        "@llvm-project//llvm:Passes",
         "@llvm-project//llvm:Support",
         "@llvm-project//llvm:TransformUtils",
     ],

toolchain/lower/context.cpp

@@ -19,10 +19,11 @@ Context::Context(
     llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> fs, bool want_debug_info,
     const Parse::GetTreeAndSubtreesStore* tree_and_subtrees_getters,
     llvm::StringRef module_name, int total_ir_count,
-    llvm::raw_ostream* vlog_stream)
+    Lower::OptimizationLevel opt_level, llvm::raw_ostream* vlog_stream)
     : llvm_context_(llvm_context),
       llvm_module_(std::make_unique<llvm::Module>(module_name, *llvm_context)),
       file_system_(std::move(fs)),
+      opt_level_(opt_level),
       di_builder_(*llvm_module_),
       di_compile_unit_(
           want_debug_info

toolchain/lower/context.h

@@ -14,6 +14,7 @@
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "toolchain/base/fixed_size_value_store.h"
+#include "toolchain/lower/options.h"
 #include "toolchain/parse/tree_and_subtrees.h"
 #include "toolchain/sem_ir/absolute_node_id.h"
 #include "toolchain/sem_ir/ids.h"
@@ -49,7 +50,7 @@ class Context {
       llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> fs, bool want_debug_info,
       const Parse::GetTreeAndSubtreesStore* tree_and_subtrees_getters,
       llvm::StringRef module_name, int total_ir_count,
-      llvm::raw_ostream* vlog_stream);
+      Lower::OptimizationLevel opt_level, llvm::raw_ostream* vlog_stream);
 
   // Gets or creates the `FileContext` for a given SemIR file. If an
   // `inst_namer` is specified the first time this is called for a file, it will
@@ -97,6 +98,7 @@ class Context {
   auto file_system() -> llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>& {
     return file_system_;
   }
+  auto opt_level() -> Lower::OptimizationLevel { return opt_level_; }
   auto di_builder() -> llvm::DIBuilder& { return di_builder_; }
   auto di_compile_unit() -> llvm::DICompileUnit* { return di_compile_unit_; }
   auto tree_and_subtrees_getters() -> const Parse::GetTreeAndSubtreesStore& {
@@ -130,6 +132,9 @@ class Context {
   // The filesystem for source code.
   llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> file_system_;
 
+  // The optimization level to specify for lowered function definitions.
+  Lower::OptimizationLevel opt_level_;
+
   // State for building the LLVM IR debug info metadata.
   llvm::DIBuilder di_builder_;
 

toolchain/lower/file_context.cpp

@@ -23,6 +23,7 @@
 #include "toolchain/lower/constant.h"
 #include "toolchain/lower/function_context.h"
 #include "toolchain/lower/mangler.h"
+#include "toolchain/lower/options.h"
 #include "toolchain/lower/specific_coalescer.h"
 #include "toolchain/sem_ir/absolute_node_id.h"
 #include "toolchain/sem_ir/diagnostic_loc_converter.h"
@@ -619,6 +620,36 @@ auto FileContext::BuildFunctionBody(SemIR::FunctionId function_id,
     AddLoweredSpecificForGeneric(declaration_function.generic_id, specific_id);
   }
 
+  // Set attributes on the function definition.
+  {
+    llvm::AttrBuilder attr_builder(llvm_context());
+    attr_builder.addAttribute(llvm::Attribute::NoUnwind);
+
+    // TODO: We should take the opt level from the SemIR file; it might not be
+    // the same for all files in a compilation.
+    if (context().opt_level() == Lower::OptimizationLevel::None) {
+      // --optimize=none disables all optimizations for this function.
+      attr_builder.addAttribute(llvm::Attribute::OptimizeNone);
+      attr_builder.addAttribute(llvm::Attribute::NoInline);
+    } else {
+      // Otherwise, always inline thunks.
+      if (definition_function.special_function_kind ==
+          SemIR::Function::SpecialFunctionKind::Thunk) {
+        attr_builder.addAttribute(llvm::Attribute::AlwaysInline);
+      }
+
+      // Convert --optimize=size into optsize and minsize.
+      if (context().opt_level() == Lower::OptimizationLevel::Size) {
+        attr_builder.addAttribute(llvm::Attribute::OptimizeForSize);
+        attr_builder.addAttribute(llvm::Attribute::MinSize);
+      }
+
+      // TODO: Should we generate an InlineHint for some functions? Perhaps for
+      // those defined in the API file?
+    }
+    llvm_function->addFnAttrs(attr_builder);
+  }
+
   FunctionContext function_lowering(
       definition_context, llvm_function, *this, specific_id,
       coalescer_.InitializeFingerprintForSpecific(specific_id),

toolchain/lower/lower.cpp

@@ -22,7 +22,7 @@ auto LowerToLLVM(
     const LowerToLLVMOptions& options) -> std::unique_ptr<llvm::Module> {
   Context context(&llvm_context, std::move(fs), options.want_debug_info,
                   &tree_and_subtrees_getters, sem_ir.filename(), total_ir_count,
-                  options.vlog_stream);
+                  options.opt_level, options.vlog_stream);
 
   // TODO: Consider disabling instruction naming by default if we're not
   // producing textual LLVM IR.
@@ -37,10 +37,6 @@ auto LowerToLLVM(
                   /*ShouldPreserveUseListOrder=*/false,
                   /*IsForDebug=*/true);
   }
-  if (options.dump_stream) {
-    module->print(*options.dump_stream, /*AAW=*/nullptr,
-                  /*ShouldPreserveUseListOrder=*/true);
-  }
 
   if (options.llvm_verifier_stream) {
     CARBON_CHECK(!llvm::verifyModule(*module, options.llvm_verifier_stream));

toolchain/lower/lower.h

@@ -8,29 +8,13 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
+#include "toolchain/lower/options.h"
 #include "toolchain/parse/tree_and_subtrees.h"
 #include "toolchain/sem_ir/file.h"
 #include "toolchain/sem_ir/inst_namer.h"
 
 namespace Carbon::Lower {
 
-struct LowerToLLVMOptions {
-  // Options must be set individually, not through initialization.
-  explicit LowerToLLVMOptions() = default;
-
-  // If set, enables LLVM IR verification.
-  llvm::raw_ostream* llvm_verifier_stream = nullptr;
-
-  // Whether to include debug info in lowered output.
-  bool want_debug_info = false;
-
-  // If set, enables verbose output.
-  llvm::raw_ostream* vlog_stream = nullptr;
-
-  // If set, LLVM IR will be dumped to this in textual form.
-  llvm::raw_ostream* dump_stream = nullptr;
-};
-
 // Lowers SemIR to LLVM IR.
 auto LowerToLLVM(
     llvm::LLVMContext& llvm_context,

toolchain/lower/options.h

@@ -0,0 +1,44 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#ifndef CARBON_TOOLCHAIN_LOWER_OPTIONS_H_
+#define CARBON_TOOLCHAIN_LOWER_OPTIONS_H_
+
+#include "llvm/Support/raw_ostream.h"
+
+namespace Carbon::Lower {
+
+enum class OptimizationLevel {
+  // No optimizations beyond necessary ones like inlining always-inline
+  // functions. Corresponds to Clang -O0.
+  None,
+  // Perform optimizations that make the build faster and don't degrade
+  // debugging. Corresponds to Clang -O1 or -Og.
+  Debug,
+  // Optimize for binary size. Corresponds to Clang -Oz.
+  Size,
+  // Optimize for program execution speed. Corresponds to Clang -O3.
+  Speed,
+};
+
+struct LowerToLLVMOptions {
+  // Options must be set individually, not through initialization.
+  explicit LowerToLLVMOptions() = default;
+
+  // If set, enables LLVM IR verification.
+  llvm::raw_ostream* llvm_verifier_stream = nullptr;
+
+  // Whether to include debug info in lowered output.
+  bool want_debug_info = false;
+
+  // If set, enables verbose output.
+  llvm::raw_ostream* vlog_stream = nullptr;
+
+  // The optimization level to set on lowered functions by default.
+  OptimizationLevel opt_level = OptimizationLevel::Debug;
+};
+
+}  // namespace Carbon::Lower
+
+#endif  // CARBON_TOOLCHAIN_LOWER_OPTIONS_H_

toolchain/lower/testdata/alias/local.carbon

@@ -19,7 +19,8 @@ fn F() -> i32 {
 // CHECK:STDOUT: ; ModuleID = 'local.carbon'
 // CHECK:STDOUT: source_filename = "local.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CF.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CF.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %a.var = alloca i32, align 4, !dbg !7
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %a.var), !dbg !7
@@ -29,9 +30,10 @@ fn F() -> i32 {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/array/array_in_place.carbon

@@ -21,7 +21,8 @@ fn G() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CF.Main(ptr sret({ i32, i32, i32 }))
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CG.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CG.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %v.var = alloca [2 x { i32, i32, i32 }], align 8, !dbg !7
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %v.var), !dbg !7
@@ -33,9 +34,10 @@ fn G() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/array/assign_return_value.carbon

@@ -21,7 +21,8 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @tuple.loc13_39 = internal constant { i32, i32 } { i32 12, i32 24 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main(ptr sret({ i32, i32 }) %return) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main(ptr sret({ i32, i32 }) %return) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %tuple.elem0.tuple.elem = getelementptr inbounds nuw { i32, i32 }, ptr %return, i32 0, i32 0, !dbg !7
 // CHECK:STDOUT:   %tuple.elem1.tuple.elem = getelementptr inbounds nuw { i32, i32 }, ptr %return, i32 0, i32 1, !dbg !7
@@ -29,7 +30,8 @@ fn Run() {
 // CHECK:STDOUT:   ret void, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @main() !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @main() #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %t.var = alloca [2 x i32], align 4, !dbg !10
 // CHECK:STDOUT:   %.loc16_28.1.temp = alloca { i32, i32 }, align 8, !dbg !11
@@ -48,16 +50,17 @@ fn Run() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #0
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #2
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/array/base.carbon

@@ -26,7 +26,8 @@ fn Run() {
 // CHECK:STDOUT: @array.1cb.loc16_3 = internal constant [5 x {}] zeroinitializer
 // CHECK:STDOUT: @tuple.loc17_3 = internal constant { i32, i32, i32 } { i32 1, i32 2, i32 3 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %a.var = alloca [1 x i32], align 4, !dbg !7
 // CHECK:STDOUT:   %b.var = alloca [2 x double], align 8, !dbg !8
@@ -69,17 +70,18 @@ fn Run() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 4, 3, 2, 1, 0 }
 // CHECK:STDOUT: uselistorder ptr @llvm.memcpy.p0.p0.i64, { 3, 2, 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/array/field.carbon

@@ -30,7 +30,8 @@ class A {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @A.val.loc16_40 = internal constant { [2 x i32] } { [2 x i32] [i32 1, i32 2] }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CInit.A.Main(ptr sret({ [2 x i32] }) %return) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CInit.A.Main(ptr sret({ [2 x i32] }) %return) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc16_39.2.v = getelementptr inbounds nuw { [2 x i32] }, ptr %return, i32 0, i32 0, !dbg !7
 // CHECK:STDOUT:   %.loc16_38.3.array.index = getelementptr inbounds [2 x i32], ptr %.loc16_39.2.v, i32 0, i64 0, !dbg !8
@@ -39,7 +40,8 @@ class A {
 // CHECK:STDOUT:   ret void, !dbg !9
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CAccess.A.Main(ptr %self) !dbg !10 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CAccess.A.Main(ptr %self) #0 !dbg !10 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc19_16.1.v = getelementptr inbounds nuw { [2 x i32] }, ptr %self, i32 0, i32 0, !dbg !11
 // CHECK:STDOUT:   %.loc19_20.2.array.index = getelementptr inbounds [2 x i32], ptr %.loc19_16.1.v, i32 0, i32 0, !dbg !11
@@ -47,7 +49,8 @@ class A {
 // CHECK:STDOUT:   ret i32 %.loc19_20.3, !dbg !12
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CUse.A.Main(ptr %self) !dbg !13 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CUse.A.Main(ptr %self) #0 !dbg !13 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc23_9.v = getelementptr inbounds nuw { [2 x i32] }, ptr %self, i32 0, i32 0, !dbg !14
 // CHECK:STDOUT:   %.loc23_13.array.index = getelementptr inbounds [2 x i32], ptr %.loc23_9.v, i32 0, i32 0, !dbg !14
@@ -59,9 +62,10 @@ class A {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #0
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/array/field_addr.carbon

@@ -30,7 +30,8 @@ class A {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @A.val.loc16_40 = internal constant { [2 x i32] } { [2 x i32] [i32 1, i32 2] }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CInit.A.Main(ptr sret({ [2 x i32] }) %return) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CInit.A.Main(ptr sret({ [2 x i32] }) %return) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc16_39.2.v = getelementptr inbounds nuw { [2 x i32] }, ptr %return, i32 0, i32 0, !dbg !7
 // CHECK:STDOUT:   %.loc16_38.3.array.index = getelementptr inbounds [2 x i32], ptr %.loc16_39.2.v, i32 0, i64 0, !dbg !8
@@ -39,7 +40,8 @@ class A {
 // CHECK:STDOUT:   ret void, !dbg !9
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CAccess.A.Main(ptr %self) !dbg !10 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CAccess.A.Main(ptr %self) #0 !dbg !10 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc19_16.1.v = getelementptr inbounds nuw { [2 x i32] }, ptr %self, i32 0, i32 0, !dbg !11
 // CHECK:STDOUT:   %.loc19_20.2.array.index = getelementptr inbounds [2 x i32], ptr %.loc19_16.1.v, i32 0, i32 0, !dbg !11
@@ -47,7 +49,8 @@ class A {
 // CHECK:STDOUT:   ret i32 %.loc19_20.3, !dbg !12
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CUse.A.Main(ptr %self) !dbg !13 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CUse.A.Main(ptr %self) #0 !dbg !13 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc23_9.2.v = getelementptr inbounds nuw { [2 x i32] }, ptr %self, i32 0, i32 0, !dbg !14
 // CHECK:STDOUT:   %.loc23_14.array.index = getelementptr inbounds [2 x i32], ptr %.loc23_9.2.v, i32 0, i32 0, !dbg !14
@@ -59,9 +62,10 @@ class A {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #0
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/array/function_param.carbon

@@ -23,14 +23,16 @@ fn G() -> i32 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @array.loc18_20.13 = internal constant [3 x i32] [i32 1, i32 2, i32 3]
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CF.Main(ptr %arr, i32 %i) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CF.Main(ptr %arr, i32 %i) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc14_15.2.array.index = getelementptr inbounds [3 x i32], ptr %arr, i32 0, i32 %i, !dbg !7
 // CHECK:STDOUT:   %.loc14_15.3 = load i32, ptr %.loc14_15.2.array.index, align 4, !dbg !7
 // CHECK:STDOUT:   ret i32 %.loc14_15.3, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CG.Main() !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CG.Main() #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc18_20.3.temp = alloca [3 x i32], align 4, !dbg !10
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc18_20.3.temp), !dbg !10
@@ -43,13 +45,14 @@ fn G() -> i32 {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/array/iterate.carbon

@@ -26,7 +26,8 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CG.Main(i32)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc16_43.3.temp = alloca [6 x i32], align 4, !dbg !7
 // CHECK:STDOUT:   %var = alloca i32, align 4, !dbg !8
@@ -60,16 +61,18 @@ fn F() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @"_CNewCursor.f06e388f4a5bd5ec:Iterate.Core.a21f6adcc8abe06c"(ptr %self) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @"_CNewCursor.f06e388f4a5bd5ec:Iterate.Core.a21f6adcc8abe06c"(ptr %self) #0 !dbg !12 {
 // CHECK:STDOUT:   ret i32 0, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_CNext.f06e388f4a5bd5ec:Iterate.Core.a21f6adcc8abe06c"(ptr sret({ i32, i1 }) %return, ptr %self, ptr %cursor) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CNext.f06e388f4a5bd5ec:Iterate.Core.a21f6adcc8abe06c"(ptr sret({ i32, i1 }) %return, ptr %self, ptr %cursor) #0 !dbg !15 {
 // CHECK:STDOUT:   %1 = load i32, ptr %cursor, align 4, !dbg !16
 // CHECK:STDOUT:   %2 = icmp slt i32 %1, 6, !dbg !16
 // CHECK:STDOUT:   br i1 %2, label %3, label %7, !dbg !17
@@ -88,45 +91,53 @@ fn F() {
 // CHECK:STDOUT:   ret void, !dbg !24
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i1 @_CHasValue.Optional.Core.c1b882a73b8b9531(ptr %self) !dbg !25 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i1 @_CHasValue.Optional.Core.c1b882a73b8b9531(ptr %self) #0 !dbg !25 {
 // CHECK:STDOUT:   %1 = call i1 @"_CHas.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %self), !dbg !27
 // CHECK:STDOUT:   ret i1 %1, !dbg !28
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CGet.Optional.Core.c1b882a73b8b9531(ptr %self) !dbg !29 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CGet.Optional.Core.c1b882a73b8b9531(ptr %self) #0 !dbg !29 {
 // CHECK:STDOUT:   %1 = call i32 @"_CGet.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %self), !dbg !30
 // CHECK:STDOUT:   ret i32 %1, !dbg !31
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_COp.Int.Core:Inc.Core.be1e879c1ad406d8"(ptr %self) !dbg !32 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_COp.Int.Core:Inc.Core.be1e879c1ad406d8"(ptr %self) #0 !dbg !32 {
 // CHECK:STDOUT:   call void @"_COp:thunk.Int.Core:AddAssignWith.Core.dbc952efa35fc763"(ptr %self, i32 1), !dbg !34
 // CHECK:STDOUT:   ret void, !dbg !35
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CSome.Optional.Core.c1b882a73b8b9531(ptr sret({ i32, i1 }) %return, i32 %value) !dbg !36 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CSome.Optional.Core.c1b882a73b8b9531(ptr sret({ i32, i1 }) %return, i32 %value) #0 !dbg !36 {
 // CHECK:STDOUT:   call void @"_CSome.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %return, i32 %value), !dbg !37
 // CHECK:STDOUT:   ret void, !dbg !38
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CNone.Optional.Core.c1b882a73b8b9531(ptr sret({ i32, i1 }) %return) !dbg !39 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CNone.Optional.Core.c1b882a73b8b9531(ptr sret({ i32, i1 }) %return) #0 !dbg !39 {
 // CHECK:STDOUT:   call void @"_CNone.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %return), !dbg !40
 // CHECK:STDOUT:   ret void, !dbg !41
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i1 @"_CHas.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %value) !dbg !42 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i1 @"_CHas.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %value) #0 !dbg !42 {
 // CHECK:STDOUT:   %has_value = getelementptr inbounds nuw { i32, i1 }, ptr %value, i32 0, i32 1, !dbg !43
 // CHECK:STDOUT:   %1 = load i8, ptr %has_value, align 1, !dbg !43
 // CHECK:STDOUT:   %2 = trunc i8 %1 to i1, !dbg !43
 // CHECK:STDOUT:   ret i1 %2, !dbg !44
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @"_CGet.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %value) !dbg !45 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @"_CGet.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %value) #0 !dbg !45 {
 // CHECK:STDOUT:   %value1 = getelementptr inbounds nuw { i32, i1 }, ptr %value, i32 0, i32 0, !dbg !46
 // CHECK:STDOUT:   %1 = load i32, ptr %value1, align 4, !dbg !46
 // CHECK:STDOUT:   ret i32 %1, !dbg !47
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_COp:thunk.Int.Core:AddAssignWith.Core.dbc952efa35fc763"(ptr %self, i32 %other) !dbg !48 {
+// CHECK:STDOUT: ; Function Attrs: alwaysinline nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_COp:thunk.Int.Core:AddAssignWith.Core.dbc952efa35fc763"(ptr %self, i32 %other) #3 !dbg !48 {
 // CHECK:STDOUT:   %1 = call i32 @"_CConvert.02bbc8f98b95ea6d:ImplicitAs.Core.5854fed63e66a74b"(i32 %other), !dbg !49
 // CHECK:STDOUT:   %2 = load i32, ptr %self, align 4, !dbg !50
 // CHECK:STDOUT:   %3 = add i32 %2, %1, !dbg !50
@@ -134,7 +145,8 @@ fn F() {
 // CHECK:STDOUT:   ret void, !dbg !50
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_CSome.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr sret({ i32, i1 }) %return, i32 %self) !dbg !51 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CSome.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr sret({ i32, i1 }) %return, i32 %self) #0 !dbg !51 {
 // CHECK:STDOUT:   %value = getelementptr inbounds nuw { i32, i1 }, ptr %return, i32 0, i32 0, !dbg !52
 // CHECK:STDOUT:   store i32 %self, ptr %value, align 4, !dbg !52
 // CHECK:STDOUT:   %has_value = getelementptr inbounds nuw { i32, i1 }, ptr %return, i32 0, i32 1, !dbg !53
@@ -142,21 +154,25 @@ fn F() {
 // CHECK:STDOUT:   ret void, !dbg !54
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_CNone.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr sret({ i32, i1 }) %return) !dbg !55 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CNone.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr sret({ i32, i1 }) %return) #0 !dbg !55 {
 // CHECK:STDOUT:   %has_value = getelementptr inbounds nuw { i32, i1 }, ptr %return, i32 0, i32 1, !dbg !56
 // CHECK:STDOUT:   store i8 0, ptr %has_value, align 1, !dbg !56
 // CHECK:STDOUT:   ret void, !dbg !57
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @"_CConvert.02bbc8f98b95ea6d:ImplicitAs.Core.5854fed63e66a74b"(i32 %self) !dbg !58 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @"_CConvert.02bbc8f98b95ea6d:ImplicitAs.Core.5854fed63e66a74b"(i32 %self) #0 !dbg !58 {
 // CHECK:STDOUT:   ret i32 %self, !dbg !60
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 2, 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #3 = { alwaysinline nounwind }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/builtins/bool.carbon

@@ -26,19 +26,22 @@ fn IfEq(a: Bool(), b: Bool()) -> Bool() {
 // CHECK:STDOUT: ; ModuleID = 'bool.carbon'
 // CHECK:STDOUT: source_filename = "bool.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestEq.Main(i1 %a, i1 %b) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestEq.Main(i1 %a, i1 %b) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Eq.call = icmp eq i1 %a, %b, !dbg !7
 // CHECK:STDOUT:   ret i1 %Eq.call, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestNeq.Main(i1 %a, i1 %b) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestNeq.Main(i1 %a, i1 %b) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Neq.call = icmp ne i1 %a, %b, !dbg !10
 // CHECK:STDOUT:   ret i1 %Neq.call, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CIfEq.Main(i1 %a, i1 %b) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CIfEq.Main(i1 %a, i1 %b) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Eq.call = icmp eq i1 %a, %b, !dbg !13
 // CHECK:STDOUT:   br i1 %Eq.call, label %if.then, label %if.else, !dbg !14
@@ -50,6 +53,8 @@ fn IfEq(a: Bool(), b: Bool()) -> Bool() {
 // CHECK:STDOUT:   ret i1 false, !dbg !16
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/builtins/char.carbon

@@ -22,7 +22,8 @@ fn Example() -> char {
 // CHECK:STDOUT: ; ModuleID = 'basic.carbon'
 // CHECK:STDOUT: source_filename = "basic.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i8 @_CExample.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i8 @_CExample.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %c.var = alloca i8, align 1, !dbg !7
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %c.var), !dbg !7
@@ -32,9 +33,10 @@ fn Example() -> char {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/builtins/float.carbon

@@ -82,72 +82,85 @@ fn TestF128(a: f128, b: f128) -> f128 { return F128(a, b); }
 // CHECK:STDOUT: ; ModuleID = 'basic.carbon'
 // CHECK:STDOUT: source_filename = "basic.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define double @_CTestNegate.Main(double %a) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define double @_CTestNegate.Main(double %a) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Negate.call = fneg double %a, !dbg !7
 // CHECK:STDOUT:   ret double %Negate.call, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define double @_CTestAdd.Main(double %a, double %b) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define double @_CTestAdd.Main(double %a, double %b) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Add.call = fadd double %a, %b, !dbg !10
 // CHECK:STDOUT:   ret double %Add.call, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define double @_CTestSub.Main(double %a, double %b) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define double @_CTestSub.Main(double %a, double %b) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Sub.call = fsub double %a, %b, !dbg !13
 // CHECK:STDOUT:   ret double %Sub.call, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define double @_CTestMul.Main(double %a, double %b) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define double @_CTestMul.Main(double %a, double %b) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Mul.call = fmul double %a, %b, !dbg !16
 // CHECK:STDOUT:   ret double %Mul.call, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define double @_CTestDiv.Main(double %a, double %b) !dbg !18 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define double @_CTestDiv.Main(double %a, double %b) #0 !dbg !18 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Div.call = fdiv double %a, %b, !dbg !19
 // CHECK:STDOUT:   ret double %Div.call, !dbg !20
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestEq.Main(double %a, double %b) !dbg !21 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestEq.Main(double %a, double %b) #0 !dbg !21 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Eq.call = fcmp oeq double %a, %b, !dbg !22
 // CHECK:STDOUT:   ret i1 %Eq.call, !dbg !23
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestNeq.Main(double %a, double %b) !dbg !24 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestNeq.Main(double %a, double %b) #0 !dbg !24 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Neq.call = fcmp one double %a, %b, !dbg !25
 // CHECK:STDOUT:   ret i1 %Neq.call, !dbg !26
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestLess.Main(double %a, double %b) !dbg !27 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestLess.Main(double %a, double %b) #0 !dbg !27 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Less.call = fcmp olt double %a, %b, !dbg !28
 // CHECK:STDOUT:   ret i1 %Less.call, !dbg !29
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestLessEq.Main(double %a, double %b) !dbg !30 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestLessEq.Main(double %a, double %b) #0 !dbg !30 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %LessEq.call = fcmp ole double %a, %b, !dbg !31
 // CHECK:STDOUT:   ret i1 %LessEq.call, !dbg !32
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestGreater.Main(double %a, double %b) !dbg !33 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestGreater.Main(double %a, double %b) #0 !dbg !33 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Greater.call = fcmp ogt double %a, %b, !dbg !34
 // CHECK:STDOUT:   ret i1 %Greater.call, !dbg !35
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestGreaterEq.Main(double %a, double %b) !dbg !36 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestGreaterEq.Main(double %a, double %b) #0 !dbg !36 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %GreaterEq.call = fcmp oge double %a, %b, !dbg !37
 // CHECK:STDOUT:   ret i1 %GreaterEq.call, !dbg !38
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:
@@ -193,7 +206,8 @@ fn TestF128(a: f128, b: f128) -> f128 { return F128(a, b); }
 // CHECK:STDOUT: ; ModuleID = 'compound_assign.carbon'
 // CHECK:STDOUT: source_filename = "compound_assign.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestAdd.Main(ptr %a, double %b) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestAdd.Main(ptr %a, double %b) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Add.call = load double, ptr %a, align 8, !dbg !7
 // CHECK:STDOUT:   %Add.call1 = fadd double %Add.call, %b, !dbg !7
@@ -201,7 +215,8 @@ fn TestF128(a: f128, b: f128) -> f128 { return F128(a, b); }
 // CHECK:STDOUT:   ret void, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestSub.Main(ptr %a, double %b) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestSub.Main(ptr %a, double %b) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Sub.call = load double, ptr %a, align 8, !dbg !10
 // CHECK:STDOUT:   %Sub.call1 = fsub double %Sub.call, %b, !dbg !10
@@ -209,7 +224,8 @@ fn TestF128(a: f128, b: f128) -> f128 { return F128(a, b); }
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestMul.Main(ptr %a, double %b) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestMul.Main(ptr %a, double %b) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Mul.call = load double, ptr %a, align 8, !dbg !13
 // CHECK:STDOUT:   %Mul.call1 = fmul double %Mul.call, %b, !dbg !13
@@ -217,7 +233,8 @@ fn TestF128(a: f128, b: f128) -> f128 { return F128(a, b); }
 // CHECK:STDOUT:   ret void, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestDiv.Main(ptr %a, double %b) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestDiv.Main(ptr %a, double %b) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Div.call = load double, ptr %a, align 8, !dbg !16
 // CHECK:STDOUT:   %Div.call1 = fdiv double %Div.call, %b, !dbg !16
@@ -225,6 +242,8 @@ fn TestF128(a: f128, b: f128) -> f128 { return F128(a, b); }
 // CHECK:STDOUT:   ret void, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:
@@ -249,30 +268,36 @@ fn TestF128(a: f128, b: f128) -> f128 { return F128(a, b); }
 // CHECK:STDOUT: ; ModuleID = 'types.carbon'
 // CHECK:STDOUT: source_filename = "types.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define half @_CTestF16.Main(half %a, half %b) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define half @_CTestF16.Main(half %a, half %b) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %F16.call = fadd half %a, %b, !dbg !7
 // CHECK:STDOUT:   ret half %F16.call, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define float @_CTestF32.Main(float %a, float %b) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define float @_CTestF32.Main(float %a, float %b) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %F32.call = fadd float %a, %b, !dbg !10
 // CHECK:STDOUT:   ret float %F32.call, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define double @_CTestF64.Main(double %a, double %b) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define double @_CTestF64.Main(double %a, double %b) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %F64.call = fadd double %a, %b, !dbg !13
 // CHECK:STDOUT:   ret double %F64.call, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define fp128 @_CTestF128.Main(fp128 %a, fp128 %b) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define fp128 @_CTestF128.Main(fp128 %a, fp128 %b) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %F128.call = fadd fp128 %a, %b, !dbg !16
 // CHECK:STDOUT:   ret fp128 %F128.call, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/builtins/int.carbon

@@ -225,120 +225,141 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT: ; ModuleID = 'basic.carbon'
 // CHECK:STDOUT: source_filename = "basic.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestNegate.Main(i32 %a) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestNegate.Main(i32 %a) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Negate.call = sub i32 0, %a, !dbg !7
 // CHECK:STDOUT:   ret i32 %Negate.call, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestAdd.Main(i32 %a, i32 %b) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestAdd.Main(i32 %a, i32 %b) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Add.call = add i32 %a, %b, !dbg !10
 // CHECK:STDOUT:   ret i32 %Add.call, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestSub.Main(i32 %a, i32 %b) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestSub.Main(i32 %a, i32 %b) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Sub.call = sub i32 %a, %b, !dbg !13
 // CHECK:STDOUT:   ret i32 %Sub.call, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestMul.Main(i32 %a, i32 %b) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestMul.Main(i32 %a, i32 %b) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Mul.call = mul i32 %a, %b, !dbg !16
 // CHECK:STDOUT:   ret i32 %Mul.call, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestDiv.Main(i32 %a, i32 %b) !dbg !18 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestDiv.Main(i32 %a, i32 %b) #0 !dbg !18 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Div.call = sdiv i32 %a, %b, !dbg !19
 // CHECK:STDOUT:   ret i32 %Div.call, !dbg !20
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestMod.Main(i32 %a, i32 %b) !dbg !21 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestMod.Main(i32 %a, i32 %b) #0 !dbg !21 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Mod.call = srem i32 %a, %b, !dbg !22
 // CHECK:STDOUT:   ret i32 %Mod.call, !dbg !23
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestComplement.Main(i32 %a) !dbg !24 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestComplement.Main(i32 %a) #0 !dbg !24 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Complement.call = xor i32 -1, %a, !dbg !25
 // CHECK:STDOUT:   ret i32 %Complement.call, !dbg !26
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestAnd.Main(i32 %a, i32 %b) !dbg !27 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestAnd.Main(i32 %a, i32 %b) #0 !dbg !27 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %And.call = and i32 %a, %b, !dbg !28
 // CHECK:STDOUT:   ret i32 %And.call, !dbg !29
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestOr.Main(i32 %a, i32 %b) !dbg !30 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestOr.Main(i32 %a, i32 %b) #0 !dbg !30 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Or.call = or i32 %a, %b, !dbg !31
 // CHECK:STDOUT:   ret i32 %Or.call, !dbg !32
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestXor.Main(i32 %a, i32 %b) !dbg !33 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestXor.Main(i32 %a, i32 %b) #0 !dbg !33 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Xor.call = xor i32 %a, %b, !dbg !34
 // CHECK:STDOUT:   ret i32 %Xor.call, !dbg !35
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestLeftShift.Main(i32 %a, i32 %b) !dbg !36 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestLeftShift.Main(i32 %a, i32 %b) #0 !dbg !36 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %LeftShift.call = shl i32 %a, %b, !dbg !37
 // CHECK:STDOUT:   ret i32 %LeftShift.call, !dbg !38
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestArithmeticRightShift.Main(i32 %a, i32 %b) !dbg !39 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestArithmeticRightShift.Main(i32 %a, i32 %b) #0 !dbg !39 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %ArithmeticRightShift.call = ashr i32 %a, %b, !dbg !40
 // CHECK:STDOUT:   ret i32 %ArithmeticRightShift.call, !dbg !41
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestLogicalRightShift.Main(i32 %a, i32 %b) !dbg !42 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestLogicalRightShift.Main(i32 %a, i32 %b) #0 !dbg !42 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %LogicalRightShift.call = lshr i32 %a, %b, !dbg !43
 // CHECK:STDOUT:   ret i32 %LogicalRightShift.call, !dbg !44
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestEq.Main(i32 %a, i32 %b) !dbg !45 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestEq.Main(i32 %a, i32 %b) #0 !dbg !45 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Eq.call = icmp eq i32 %a, %b, !dbg !46
 // CHECK:STDOUT:   ret i1 %Eq.call, !dbg !47
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestNeq.Main(i32 %a, i32 %b) !dbg !48 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestNeq.Main(i32 %a, i32 %b) #0 !dbg !48 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Neq.call = icmp ne i32 %a, %b, !dbg !49
 // CHECK:STDOUT:   ret i1 %Neq.call, !dbg !50
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestLess.Main(i32 %a, i32 %b) !dbg !51 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestLess.Main(i32 %a, i32 %b) #0 !dbg !51 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Less.call = icmp slt i32 %a, %b, !dbg !52
 // CHECK:STDOUT:   ret i1 %Less.call, !dbg !53
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestLessEq.Main(i32 %a, i32 %b) !dbg !54 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestLessEq.Main(i32 %a, i32 %b) #0 !dbg !54 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %LessEq.call = icmp sle i32 %a, %b, !dbg !55
 // CHECK:STDOUT:   ret i1 %LessEq.call, !dbg !56
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestGreater.Main(i32 %a, i32 %b) !dbg !57 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestGreater.Main(i32 %a, i32 %b) #0 !dbg !57 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Greater.call = icmp sgt i32 %a, %b, !dbg !58
 // CHECK:STDOUT:   ret i1 %Greater.call, !dbg !59
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestGreaterEq.Main(i32 %a, i32 %b) !dbg !60 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestGreaterEq.Main(i32 %a, i32 %b) #0 !dbg !60 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %GreaterEq.call = icmp sge i32 %a, %b, !dbg !61
 // CHECK:STDOUT:   ret i1 %GreaterEq.call, !dbg !62
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:
@@ -408,7 +429,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT: ; ModuleID = 'compound_assign.carbon'
 // CHECK:STDOUT: source_filename = "compound_assign.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestSAdd.Main(ptr %a, i32 %b) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestSAdd.Main(ptr %a, i32 %b) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %SAdd.call = load i32, ptr %a, align 4, !dbg !7
 // CHECK:STDOUT:   %SAdd.call1 = add i32 %SAdd.call, %b, !dbg !7
@@ -416,7 +438,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestSSub.Main(ptr %a, i32 %b) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestSSub.Main(ptr %a, i32 %b) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %SSub.call = load i32, ptr %a, align 4, !dbg !10
 // CHECK:STDOUT:   %SSub.call1 = sub i32 %SSub.call, %b, !dbg !10
@@ -424,7 +447,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestSMul.Main(ptr %a, i32 %b) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestSMul.Main(ptr %a, i32 %b) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %SMul.call = load i32, ptr %a, align 4, !dbg !13
 // CHECK:STDOUT:   %SMul.call1 = mul i32 %SMul.call, %b, !dbg !13
@@ -432,7 +456,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestSDiv.Main(ptr %a, i32 %b) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestSDiv.Main(ptr %a, i32 %b) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %SDiv.call = load i32, ptr %a, align 4, !dbg !16
 // CHECK:STDOUT:   %SDiv.call1 = sdiv i32 %SDiv.call, %b, !dbg !16
@@ -440,7 +465,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestSMod.Main(ptr %a, i32 %b) !dbg !18 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestSMod.Main(ptr %a, i32 %b) #0 !dbg !18 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %SMod.call = load i32, ptr %a, align 4, !dbg !19
 // CHECK:STDOUT:   %SMod.call1 = srem i32 %SMod.call, %b, !dbg !19
@@ -448,7 +474,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !20
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestUAdd.Main(ptr %a, i32 %b) !dbg !21 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestUAdd.Main(ptr %a, i32 %b) #0 !dbg !21 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %UAdd.call = load i32, ptr %a, align 4, !dbg !22
 // CHECK:STDOUT:   %UAdd.call1 = add i32 %UAdd.call, %b, !dbg !22
@@ -456,7 +483,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !23
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestUSub.Main(ptr %a, i32 %b) !dbg !24 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestUSub.Main(ptr %a, i32 %b) #0 !dbg !24 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %USub.call = load i32, ptr %a, align 4, !dbg !25
 // CHECK:STDOUT:   %USub.call1 = sub i32 %USub.call, %b, !dbg !25
@@ -464,7 +492,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !26
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestUMul.Main(ptr %a, i32 %b) !dbg !27 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestUMul.Main(ptr %a, i32 %b) #0 !dbg !27 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %UMul.call = load i32, ptr %a, align 4, !dbg !28
 // CHECK:STDOUT:   %UMul.call1 = mul i32 %UMul.call, %b, !dbg !28
@@ -472,7 +501,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !29
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestUDiv.Main(ptr %a, i32 %b) !dbg !30 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestUDiv.Main(ptr %a, i32 %b) #0 !dbg !30 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %UDiv.call = load i32, ptr %a, align 4, !dbg !31
 // CHECK:STDOUT:   %UDiv.call1 = udiv i32 %UDiv.call, %b, !dbg !31
@@ -480,7 +510,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !32
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestUMod.Main(ptr %a, i32 %b) !dbg !33 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestUMod.Main(ptr %a, i32 %b) #0 !dbg !33 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %UMod.call = load i32, ptr %a, align 4, !dbg !34
 // CHECK:STDOUT:   %UMod.call1 = urem i32 %UMod.call, %b, !dbg !34
@@ -488,7 +519,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !35
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestAnd.Main(ptr %a, i32 %b) !dbg !36 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestAnd.Main(ptr %a, i32 %b) #0 !dbg !36 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %And.call = load i32, ptr %a, align 4, !dbg !37
 // CHECK:STDOUT:   %And.call1 = and i32 %And.call, %b, !dbg !37
@@ -496,7 +528,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !38
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestOr.Main(ptr %a, i32 %b) !dbg !39 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestOr.Main(ptr %a, i32 %b) #0 !dbg !39 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Or.call = load i32, ptr %a, align 4, !dbg !40
 // CHECK:STDOUT:   %Or.call1 = or i32 %Or.call, %b, !dbg !40
@@ -504,7 +537,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !41
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestXor.Main(ptr %a, i32 %b) !dbg !42 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestXor.Main(ptr %a, i32 %b) #0 !dbg !42 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Xor.call = load i32, ptr %a, align 4, !dbg !43
 // CHECK:STDOUT:   %Xor.call1 = xor i32 %Xor.call, %b, !dbg !43
@@ -512,7 +546,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !44
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestLeftShift.Main(ptr %a, i32 %b) !dbg !45 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestLeftShift.Main(ptr %a, i32 %b) #0 !dbg !45 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %LeftShift.call = load i32, ptr %a, align 4, !dbg !46
 // CHECK:STDOUT:   %LeftShift.call1 = shl i32 %LeftShift.call, %b, !dbg !46
@@ -520,7 +555,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !47
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestArithmeticRightShift.Main(ptr %a, i32 %b) !dbg !48 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestArithmeticRightShift.Main(ptr %a, i32 %b) #0 !dbg !48 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %ArithmeticRightShift.call = load i32, ptr %a, align 4, !dbg !49
 // CHECK:STDOUT:   %ArithmeticRightShift.call1 = ashr i32 %ArithmeticRightShift.call, %b, !dbg !49
@@ -528,7 +564,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !50
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTestLogicalRightShift.Main(ptr %a, i32 %b) !dbg !51 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTestLogicalRightShift.Main(ptr %a, i32 %b) #0 !dbg !51 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %LogicalRightShift.call = load i32, ptr %a, align 4, !dbg !52
 // CHECK:STDOUT:   %LogicalRightShift.call1 = lshr i32 %LogicalRightShift.call, %b, !dbg !52
@@ -536,6 +573,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret void, !dbg !53
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:
@@ -596,76 +635,88 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT: ; ModuleID = 'mixed_shift.carbon'
 // CHECK:STDOUT: source_filename = "mixed_shift.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestLeftShiftSmaller.Main(i32 %a, i16 %b) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestLeftShiftSmaller.Main(i32 %a, i16 %b) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %LeftShiftSmaller.call.rhs = zext i16 %b to i32, !dbg !7
 // CHECK:STDOUT:   %LeftShiftSmaller.call = shl i32 %a, %LeftShiftSmaller.call.rhs, !dbg !7
 // CHECK:STDOUT:   ret i32 %LeftShiftSmaller.call, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestRightShiftSmaller.Main(i32 %a, i16 %b) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestRightShiftSmaller.Main(i32 %a, i16 %b) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %RightShiftSmaller.call.rhs = zext i16 %b to i32, !dbg !10
 // CHECK:STDOUT:   %RightShiftSmaller.call = ashr i32 %a, %RightShiftSmaller.call.rhs, !dbg !10
 // CHECK:STDOUT:   ret i32 %RightShiftSmaller.call, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i16 @_CTestLeftShiftLargerII.Main(i16 %a, i32 %b) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i16 @_CTestLeftShiftLargerII.Main(i16 %a, i32 %b) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %LeftShiftLargerII.call.rhs = trunc i32 %b to i16, !dbg !13
 // CHECK:STDOUT:   %LeftShiftLargerII.call = shl i16 %a, %LeftShiftLargerII.call.rhs, !dbg !13
 // CHECK:STDOUT:   ret i16 %LeftShiftLargerII.call, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i16 @_CTestRightShiftLargerII.Main(i16 %a, i32 %b) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i16 @_CTestRightShiftLargerII.Main(i16 %a, i32 %b) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %RightShiftLargerII.call.rhs = trunc i32 %b to i16, !dbg !16
 // CHECK:STDOUT:   %RightShiftLargerII.call = ashr i16 %a, %RightShiftLargerII.call.rhs, !dbg !16
 // CHECK:STDOUT:   ret i16 %RightShiftLargerII.call, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i16 @_CTestLeftShiftLargerIU.Main(i16 %a, i32 %b) !dbg !18 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i16 @_CTestLeftShiftLargerIU.Main(i16 %a, i32 %b) #0 !dbg !18 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %LeftShiftLargerIU.call.rhs = trunc i32 %b to i16, !dbg !19
 // CHECK:STDOUT:   %LeftShiftLargerIU.call = shl i16 %a, %LeftShiftLargerIU.call.rhs, !dbg !19
 // CHECK:STDOUT:   ret i16 %LeftShiftLargerIU.call, !dbg !20
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i16 @_CTestRightShiftLargerIU.Main(i16 %a, i32 %b) !dbg !21 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i16 @_CTestRightShiftLargerIU.Main(i16 %a, i32 %b) #0 !dbg !21 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %RightShiftLargerIU.call.rhs = trunc i32 %b to i16, !dbg !22
 // CHECK:STDOUT:   %RightShiftLargerIU.call = ashr i16 %a, %RightShiftLargerIU.call.rhs, !dbg !22
 // CHECK:STDOUT:   ret i16 %RightShiftLargerIU.call, !dbg !23
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i16 @_CTestLeftShiftLargerUI.Main(i16 %a, i32 %b) !dbg !24 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i16 @_CTestLeftShiftLargerUI.Main(i16 %a, i32 %b) #0 !dbg !24 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %LeftShiftLargerUI.call.rhs = trunc i32 %b to i16, !dbg !25
 // CHECK:STDOUT:   %LeftShiftLargerUI.call = shl i16 %a, %LeftShiftLargerUI.call.rhs, !dbg !25
 // CHECK:STDOUT:   ret i16 %LeftShiftLargerUI.call, !dbg !26
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i16 @_CTestRightShiftLargerUI.Main(i16 %a, i32 %b) !dbg !27 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i16 @_CTestRightShiftLargerUI.Main(i16 %a, i32 %b) #0 !dbg !27 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %RightShiftLargerUI.call.rhs = trunc i32 %b to i16, !dbg !28
 // CHECK:STDOUT:   %RightShiftLargerUI.call = lshr i16 %a, %RightShiftLargerUI.call.rhs, !dbg !28
 // CHECK:STDOUT:   ret i16 %RightShiftLargerUI.call, !dbg !29
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i16 @_CTestLeftShiftLargerUU.Main(i16 %a, i32 %b) !dbg !30 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i16 @_CTestLeftShiftLargerUU.Main(i16 %a, i32 %b) #0 !dbg !30 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %LeftShiftLargerUU.call.rhs = trunc i32 %b to i16, !dbg !31
 // CHECK:STDOUT:   %LeftShiftLargerUU.call = shl i16 %a, %LeftShiftLargerUU.call.rhs, !dbg !31
 // CHECK:STDOUT:   ret i16 %LeftShiftLargerUU.call, !dbg !32
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i16 @_CTestRightShiftLargerUU.Main(i16 %a, i32 %b) !dbg !33 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i16 @_CTestRightShiftLargerUU.Main(i16 %a, i32 %b) #0 !dbg !33 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %RightShiftLargerUU.call.rhs = trunc i32 %b to i16, !dbg !34
 // CHECK:STDOUT:   %RightShiftLargerUU.call = lshr i16 %a, %RightShiftLargerUU.call.rhs, !dbg !34
 // CHECK:STDOUT:   ret i16 %RightShiftLargerUU.call, !dbg !35
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:
@@ -708,14 +759,16 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT: ; ModuleID = 'mixed_compare.carbon'
 // CHECK:STDOUT: source_filename = "mixed_compare.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestEq_u16_u32.Main(i16 %a, i32 %b) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestEq_u16_u32.Main(i16 %a, i32 %b) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Eq_u16_u32.call.lhs = zext i16 %a to i32, !dbg !7
 // CHECK:STDOUT:   %Eq_u16_u32.call = icmp eq i32 %Eq_u16_u32.call.lhs, %b, !dbg !7
 // CHECK:STDOUT:   ret i1 %Eq_u16_u32.call, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestEq_i16_u32.Main(i16 %a, i32 %b) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestEq_i16_u32.Main(i16 %a, i32 %b) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Eq_i16_u32.call.lhs = sext i16 %a to i33, !dbg !10
 // CHECK:STDOUT:   %Eq_i16_u32.call.rhs = zext i32 %b to i33, !dbg !10
@@ -723,21 +776,24 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret i1 %Eq_i16_u32.call, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestEq_u16_i32.Main(i16 %a, i32 %b) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestEq_u16_i32.Main(i16 %a, i32 %b) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Eq_u16_i32.call.lhs = zext i16 %a to i32, !dbg !13
 // CHECK:STDOUT:   %Eq_u16_i32.call = icmp eq i32 %Eq_u16_i32.call.lhs, %b, !dbg !13
 // CHECK:STDOUT:   ret i1 %Eq_u16_i32.call, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestEq_i16_i32.Main(i16 %a, i32 %b) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestEq_i16_i32.Main(i16 %a, i32 %b) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Eq_i16_i32.call.lhs = sext i16 %a to i32, !dbg !16
 // CHECK:STDOUT:   %Eq_i16_i32.call = icmp eq i32 %Eq_i16_i32.call.lhs, %b, !dbg !16
 // CHECK:STDOUT:   ret i1 %Eq_i16_i32.call, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestEq_i32_u32.Main(i32 %a, i32 %b) !dbg !18 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestEq_i32_u32.Main(i32 %a, i32 %b) #0 !dbg !18 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Eq_i32_u32.call.lhs = sext i32 %a to i33, !dbg !19
 // CHECK:STDOUT:   %Eq_i32_u32.call.rhs = zext i32 %b to i33, !dbg !19
@@ -745,14 +801,16 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret i1 %Eq_i32_u32.call, !dbg !20
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestLess_u16_u32.Main(i16 %a, i32 %b) !dbg !21 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestLess_u16_u32.Main(i16 %a, i32 %b) #0 !dbg !21 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Less_u16_u32.call.lhs = zext i16 %a to i32, !dbg !22
 // CHECK:STDOUT:   %Less_u16_u32.call = icmp ult i32 %Less_u16_u32.call.lhs, %b, !dbg !22
 // CHECK:STDOUT:   ret i1 %Less_u16_u32.call, !dbg !23
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestLess_i16_u32.Main(i16 %a, i32 %b) !dbg !24 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestLess_i16_u32.Main(i16 %a, i32 %b) #0 !dbg !24 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Less_i16_u32.call.lhs = sext i16 %a to i33, !dbg !25
 // CHECK:STDOUT:   %Less_i16_u32.call.rhs = zext i32 %b to i33, !dbg !25
@@ -760,21 +818,24 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret i1 %Less_i16_u32.call, !dbg !26
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestLess_u16_i32.Main(i16 %a, i32 %b) !dbg !27 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestLess_u16_i32.Main(i16 %a, i32 %b) #0 !dbg !27 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Less_u16_i32.call.lhs = zext i16 %a to i32, !dbg !28
 // CHECK:STDOUT:   %Less_u16_i32.call = icmp slt i32 %Less_u16_i32.call.lhs, %b, !dbg !28
 // CHECK:STDOUT:   ret i1 %Less_u16_i32.call, !dbg !29
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestLess_i16_i32.Main(i16 %a, i32 %b) !dbg !30 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestLess_i16_i32.Main(i16 %a, i32 %b) #0 !dbg !30 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Less_i16_i32.call.lhs = sext i16 %a to i32, !dbg !31
 // CHECK:STDOUT:   %Less_i16_i32.call = icmp slt i32 %Less_i16_i32.call.lhs, %b, !dbg !31
 // CHECK:STDOUT:   ret i1 %Less_i16_i32.call, !dbg !32
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestLess_i32_u32.Main(i32 %a, i32 %b) !dbg !33 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestLess_i32_u32.Main(i32 %a, i32 %b) #0 !dbg !33 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Less_i32_u32.call.lhs = sext i32 %a to i33, !dbg !34
 // CHECK:STDOUT:   %Less_i32_u32.call.rhs = zext i32 %b to i33, !dbg !34
@@ -782,6 +843,8 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:   ret i1 %Less_i32_u32.call, !dbg !35
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:
@@ -824,74 +887,88 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT: ; ModuleID = 'convert.carbon'
 // CHECK:STDOUT: source_filename = "convert.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestInt32ToInt32.Main(i32 %a) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestInt32ToInt32.Main(i32 %a) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret i32 %a, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestInt32ToUint32.Main(i32 %a) !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestInt32ToUint32.Main(i32 %a) #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret i32 %a, !dbg !9
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestUint32ToInt32.Main(i32 %a) !dbg !10 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestUint32ToInt32.Main(i32 %a) #0 !dbg !10 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret i32 %a, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestUint32ToUint32.Main(i32 %a) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestUint32ToUint32.Main(i32 %a) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret i32 %a, !dbg !13
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i16 @_CTestInt32ToInt16.Main(i32 %a) !dbg !14 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i16 @_CTestInt32ToInt16.Main(i32 %a) #0 !dbg !14 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int32ToInt16.call = trunc i32 %a to i16, !dbg !15
 // CHECK:STDOUT:   ret i16 %Int32ToInt16.call, !dbg !16
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i16 @_CTestInt32ToUint16.Main(i32 %a) !dbg !17 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i16 @_CTestInt32ToUint16.Main(i32 %a) #0 !dbg !17 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int32ToUint16.call = trunc i32 %a to i16, !dbg !18
 // CHECK:STDOUT:   ret i16 %Int32ToUint16.call, !dbg !19
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i16 @_CTestUint32ToInt16.Main(i32 %a) !dbg !20 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i16 @_CTestUint32ToInt16.Main(i32 %a) #0 !dbg !20 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Uint32ToInt16.call = trunc i32 %a to i16, !dbg !21
 // CHECK:STDOUT:   ret i16 %Uint32ToInt16.call, !dbg !22
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i16 @_CTestUint32ToUint16.Main(i32 %a) !dbg !23 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i16 @_CTestUint32ToUint16.Main(i32 %a) #0 !dbg !23 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Uint32ToUint16.call = trunc i32 %a to i16, !dbg !24
 // CHECK:STDOUT:   ret i16 %Uint32ToUint16.call, !dbg !25
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestInt32ToInt64.Main(i32 %a) !dbg !26 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestInt32ToInt64.Main(i32 %a) #0 !dbg !26 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int32ToInt64.call = sext i32 %a to i64, !dbg !27
 // CHECK:STDOUT:   ret i64 %Int32ToInt64.call, !dbg !28
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestInt32ToUint64.Main(i32 %a) !dbg !29 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestInt32ToUint64.Main(i32 %a) #0 !dbg !29 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int32ToUint64.call = sext i32 %a to i64, !dbg !30
 // CHECK:STDOUT:   ret i64 %Int32ToUint64.call, !dbg !31
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestUint32ToInt64.Main(i32 %a) !dbg !32 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestUint32ToInt64.Main(i32 %a) #0 !dbg !32 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Uint32ToInt64.call = zext i32 %a to i64, !dbg !33
 // CHECK:STDOUT:   ret i64 %Uint32ToInt64.call, !dbg !34
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestUint32ToUint64.Main(i32 %a) !dbg !35 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestUint32ToUint64.Main(i32 %a) #0 !dbg !35 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Uint32ToUint64.call = zext i32 %a to i64, !dbg !36
 // CHECK:STDOUT:   ret i64 %Uint32ToUint64.call, !dbg !37
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/builtins/int_literal.carbon

@@ -31,26 +31,32 @@ fn IntMin() -> i32 {
 // CHECK:STDOUT: ; ModuleID = 'int_literal.carbon'
 // CHECK:STDOUT: source_filename = "int_literal.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define {} @_CCopy.Main({} %x) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define {} @_CCopy.Main({} %x) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret {} %x, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CMinusOne.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CMinusOne.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret i32 -1, !dbg !9
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CIntMax.Main() !dbg !10 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CIntMax.Main() #0 !dbg !10 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret i32 2147483647, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CIntMin.Main() !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CIntMin.Main() #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret i32 -2147483648, !dbg !13
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/builtins/maybe_unformed.carbon

@@ -37,14 +37,16 @@ fn PassAdapter() {
 // CHECK:STDOUT: ; ModuleID = 'maybe_unformed.carbon'
 // CHECK:STDOUT: source_filename = "maybe_unformed.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTakeBuiltin.Main(ptr %x) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTakeBuiltin.Main(ptr %x) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CMakeBuiltin.Main(ptr sret(i32))
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CPassBuiltin.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CPassBuiltin.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc21_27.1.temp = alloca i32, align 4, !dbg !9
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc21_27.1.temp), !dbg !9
@@ -53,14 +55,16 @@ fn PassAdapter() {
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTakeAdapter.Main(ptr %x) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTakeAdapter.Main(ptr %x) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !13
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CMakeAdapter.Main(ptr sret(i32))
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CPassAdapter.Main() !dbg !14 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CPassAdapter.Main() #0 !dbg !14 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc34_27.1.temp = alloca i32, align 4, !dbg !15
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc34_27.1.temp), !dbg !15
@@ -70,12 +74,13 @@ fn PassAdapter() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/builtins/method_vs_nonmethod.carbon

@@ -19,18 +19,22 @@ fn TestAddMethod(a: i32, b: i32) -> i32 { return a.(AddMethod)(b); }
 // CHECK:STDOUT: ; ModuleID = 'method_vs_nonmethod.carbon'
 // CHECK:STDOUT: source_filename = "method_vs_nonmethod.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestAddNonmethod.Main(i32 %a, i32 %b) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestAddNonmethod.Main(i32 %a, i32 %b) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %AddNonmethod.call = add i32 %a, %b, !dbg !7
 // CHECK:STDOUT:   ret i32 %AddNonmethod.call, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CTestAddMethod.Main(i32 %a, i32 %b) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CTestAddMethod.Main(i32 %a, i32 %b) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %AddMethod.call = add i32 %a, %b, !dbg !10
 // CHECK:STDOUT:   ret i32 %AddMethod.call, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/builtins/no_op.carbon

@@ -36,26 +36,30 @@ fn J() {
 // CHECK:STDOUT: ; ModuleID = 'no_op.carbon'
 // CHECK:STDOUT: source_filename = "no_op.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CG.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CG.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %a.var = alloca {}, align 8, !dbg !9
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %a.var), !dbg !9
 // CHECK:STDOUT:   ret void, !dbg !10
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CH.Main() !dbg !11 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CH.Main() #0 !dbg !11 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !12
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CI.Main()
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CJ.Main() !dbg !13 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CJ.Main() #0 !dbg !13 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc33_11.1.temp = alloca {}, align 8, !dbg !14
 // CHECK:STDOUT:   call void @_CI.Main(), !dbg !14
@@ -64,12 +68,13 @@ fn J() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/builtins/overloaded_operator.carbon

@@ -17,13 +17,16 @@ fn AddThreeIntegers(a: i32, b: i32, c: i32) -> i32 {
 // CHECK:STDOUT: ; ModuleID = 'overloaded_operator.carbon'
 // CHECK:STDOUT: source_filename = "overloaded_operator.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CAddThreeIntegers.Main(i32 %a, i32 %b, i32 %c) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CAddThreeIntegers.Main(i32 %a, i32 %b, i32 %c) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.AddWith.impl.Op.call.loc14_12 = add i32 %a, %b, !dbg !7
 // CHECK:STDOUT:   %Int.as.AddWith.impl.Op.call.loc14_16 = add i32 %Int.as.AddWith.impl.Op.call.loc14_12, %c, !dbg !7
 // CHECK:STDOUT:   ret i32 %Int.as.AddWith.impl.Op.call.loc14_16, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/builtins/pointer.carbon

@@ -27,19 +27,23 @@ fn Check(p: MakeUnformed(C*)) -> bool {
 // CHECK:STDOUT: ; ModuleID = 'pointer.carbon'
 // CHECK:STDOUT: source_filename = "pointer.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CNull.Main(ptr sret(ptr) %return) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CNull.Main(ptr sret(ptr) %return) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   store ptr null, ptr %return, align 8, !dbg !7
 // CHECK:STDOUT:   ret void, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CCheck.Main(ptr %p) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CCheck.Main(ptr %p) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %IsNull.call = load ptr, ptr %p, align 8, !dbg !10
 // CHECK:STDOUT:   %IsNull.call1 = icmp eq ptr %IsNull.call, null, !dbg !10
 // CHECK:STDOUT:   ret i1 %IsNull.call1, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/builtins/print_read.carbon

@@ -32,7 +32,8 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @printf.int.format = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 1), !dbg !7
 // CHECK:STDOUT:   br label %while.cond, !dbg !8
@@ -67,6 +68,8 @@ fn Main() {
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @putchar, { 1, 0 }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/builtins/type.carbon

@@ -41,11 +41,14 @@ fn F() {
 // CHECK:STDOUT: ; ModuleID = 'can_destroy.carbon'
 // CHECK:STDOUT: source_filename = "can_destroy.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:
@@ -63,11 +66,14 @@ fn F() {
 // CHECK:STDOUT: @_Ca.Main = global {} zeroinitializer
 // CHECK:STDOUT: @_Cb.Main = global {} zeroinitializer
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/builtins/types.carbon

@@ -40,7 +40,8 @@ fn Uses() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CBoolParam.Main(i1)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CUses.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CUses.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CIntParam.Main(i32 1), !dbg !7
 // CHECK:STDOUT:   call void @_CFloatParam.Main(half 0xH3C00, float 1.000000e+00, double 1.000000e+00, fp128 0xL00000000000000003FFF000000000000), !dbg !8
@@ -48,6 +49,8 @@ fn Uses() {
 // CHECK:STDOUT:   ret void, !dbg !10
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/builtins/uint.carbon

@@ -67,114 +67,134 @@ fn TestGreaterEq(a: u64, b: u64) -> bool { return GreaterEq(a, b); }
 // CHECK:STDOUT: ; ModuleID = 'uint.carbon'
 // CHECK:STDOUT: source_filename = "uint.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestNegate.Main(i64 %a) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestNegate.Main(i64 %a) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Negate.call = sub i64 0, %a, !dbg !7
 // CHECK:STDOUT:   ret i64 %Negate.call, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestAdd.Main(i64 %a, i64 %b) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestAdd.Main(i64 %a, i64 %b) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Add.call = add i64 %a, %b, !dbg !10
 // CHECK:STDOUT:   ret i64 %Add.call, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestSub.Main(i64 %a, i64 %b) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestSub.Main(i64 %a, i64 %b) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Sub.call = sub i64 %a, %b, !dbg !13
 // CHECK:STDOUT:   ret i64 %Sub.call, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestMul.Main(i64 %a, i64 %b) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestMul.Main(i64 %a, i64 %b) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Mul.call = mul i64 %a, %b, !dbg !16
 // CHECK:STDOUT:   ret i64 %Mul.call, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestDiv.Main(i64 %a, i64 %b) !dbg !18 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestDiv.Main(i64 %a, i64 %b) #0 !dbg !18 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Div.call = udiv i64 %a, %b, !dbg !19
 // CHECK:STDOUT:   ret i64 %Div.call, !dbg !20
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestMod.Main(i64 %a, i64 %b) !dbg !21 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestMod.Main(i64 %a, i64 %b) #0 !dbg !21 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Mod.call = urem i64 %a, %b, !dbg !22
 // CHECK:STDOUT:   ret i64 %Mod.call, !dbg !23
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestComplement.Main(i64 %a) !dbg !24 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestComplement.Main(i64 %a) #0 !dbg !24 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Complement.call = xor i64 -1, %a, !dbg !25
 // CHECK:STDOUT:   ret i64 %Complement.call, !dbg !26
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestAnd.Main(i64 %a, i64 %b) !dbg !27 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestAnd.Main(i64 %a, i64 %b) #0 !dbg !27 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %And.call = and i64 %a, %b, !dbg !28
 // CHECK:STDOUT:   ret i64 %And.call, !dbg !29
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestOr.Main(i64 %a, i64 %b) !dbg !30 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestOr.Main(i64 %a, i64 %b) #0 !dbg !30 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Or.call = or i64 %a, %b, !dbg !31
 // CHECK:STDOUT:   ret i64 %Or.call, !dbg !32
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestXor.Main(i64 %a, i64 %b) !dbg !33 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestXor.Main(i64 %a, i64 %b) #0 !dbg !33 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Xor.call = xor i64 %a, %b, !dbg !34
 // CHECK:STDOUT:   ret i64 %Xor.call, !dbg !35
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestLeftShift.Main(i64 %a, i64 %b) !dbg !36 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestLeftShift.Main(i64 %a, i64 %b) #0 !dbg !36 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %LeftShift.call = shl i64 %a, %b, !dbg !37
 // CHECK:STDOUT:   ret i64 %LeftShift.call, !dbg !38
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i64 @_CTestRightShift.Main(i64 %a, i64 %b) !dbg !39 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i64 @_CTestRightShift.Main(i64 %a, i64 %b) #0 !dbg !39 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %RightShift.call = lshr i64 %a, %b, !dbg !40
 // CHECK:STDOUT:   ret i64 %RightShift.call, !dbg !41
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestEq.Main(i64 %a, i64 %b) !dbg !42 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestEq.Main(i64 %a, i64 %b) #0 !dbg !42 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Eq.call = icmp eq i64 %a, %b, !dbg !43
 // CHECK:STDOUT:   ret i1 %Eq.call, !dbg !44
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestNeq.Main(i64 %a, i64 %b) !dbg !45 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestNeq.Main(i64 %a, i64 %b) #0 !dbg !45 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Neq.call = icmp ne i64 %a, %b, !dbg !46
 // CHECK:STDOUT:   ret i1 %Neq.call, !dbg !47
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestLess.Main(i64 %a, i64 %b) !dbg !48 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestLess.Main(i64 %a, i64 %b) #0 !dbg !48 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Less.call = icmp ult i64 %a, %b, !dbg !49
 // CHECK:STDOUT:   ret i1 %Less.call, !dbg !50
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestLessEq.Main(i64 %a, i64 %b) !dbg !51 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestLessEq.Main(i64 %a, i64 %b) #0 !dbg !51 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %LessEq.call = icmp ule i64 %a, %b, !dbg !52
 // CHECK:STDOUT:   ret i1 %LessEq.call, !dbg !53
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestGreater.Main(i64 %a, i64 %b) !dbg !54 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestGreater.Main(i64 %a, i64 %b) #0 !dbg !54 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Greater.call = icmp ugt i64 %a, %b, !dbg !55
 // CHECK:STDOUT:   ret i1 %Greater.call, !dbg !56
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CTestGreaterEq.Main(i64 %a, i64 %b) !dbg !57 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CTestGreaterEq.Main(i64 %a, i64 %b) #0 !dbg !57 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %GreaterEq.call = icmp uge i64 %a, %b, !dbg !58
 // CHECK:STDOUT:   ret i1 %GreaterEq.call, !dbg !59
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/class/adapt.carbon

@@ -62,7 +62,8 @@ fn DoStuff(a: Int) -> Int {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @PairOfInts.val.loc9_28 = internal constant { i32, i32 } { i32 1, i32 2 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMake.PairOfInts.Main(ptr sret({ i32, i32 }) %return) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMake.PairOfInts.Main(ptr sret({ i32, i32 }) %return) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc9_27.3.a = getelementptr inbounds nuw { i32, i32 }, ptr %return, i32 0, i32 0, !dbg !7
 // CHECK:STDOUT:   %.loc9_27.6.b = getelementptr inbounds nuw { i32, i32 }, ptr %return, i32 0, i32 1, !dbg !7
@@ -70,20 +71,23 @@ fn DoStuff(a: Int) -> Int {
 // CHECK:STDOUT:   ret void, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMake.PairAdapter.Main(ptr sret({ i32, i32 }) %return) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMake.PairAdapter.Main(ptr sret({ i32, i32 }) %return) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CMake.PairOfInts.Main(ptr %return), !dbg !10
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CGetB.PairAdapter.Main(ptr %self) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CGetB.PairAdapter.Main(ptr %self) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc22_14.1.b = getelementptr inbounds nuw { i32, i32 }, ptr %self, i32 0, i32 1, !dbg !13
 // CHECK:STDOUT:   %.loc22_14.2 = load i32, ptr %.loc22_14.1.b, align 4, !dbg !13
 // CHECK:STDOUT:   ret i32 %.loc22_14.2, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CUse.Main() !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CUse.Main() #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %pa.var = alloca { i32, i32 }, align 8, !dbg !16
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %pa.var), !dbg !16
@@ -93,13 +97,14 @@ fn DoStuff(a: Int) -> Int {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #0
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #2
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
@@ -127,17 +132,21 @@ fn DoStuff(a: Int) -> Int {
 // CHECK:STDOUT: ; ModuleID = 'adapt_int.carbon'
 // CHECK:STDOUT: source_filename = "adapt_int.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @"_COp.Int.Main:Copy.Core"(i32 %self) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @"_COp.Int.Main:Copy.Core"(i32 %self) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret i32 %self, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CDoStuff.Main(i32 %a) !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CDoStuff.Main(i32 %a) #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.Copy.impl.Op.call = call i32 @"_COp.Int.Main:Copy.Core"(i32 %a), !dbg !9
 // CHECK:STDOUT:   ret i32 %Int.as.Copy.impl.Op.call, !dbg !10
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/class/base.carbon

@@ -37,7 +37,8 @@ fn Convert(p: Derived*) -> Base* {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @Derived.val.loc24_36 = internal constant { { i32 }, i32 } { { i32 } { i32 4 }, i32 7 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMake.Main(ptr sret({ { i32 }, i32 }) %return) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMake.Main(ptr sret({ { i32 }, i32 }) %return) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc24_35.2.base = getelementptr inbounds nuw { { i32 }, i32 }, ptr %return, i32 0, i32 0, !dbg !7
 // CHECK:STDOUT:   %.loc24_26.3.b = getelementptr inbounds nuw { i32 }, ptr %.loc24_35.2.base, i32 0, i32 0, !dbg !8
@@ -46,7 +47,8 @@ fn Convert(p: Derived*) -> Base* {
 // CHECK:STDOUT:   ret void, !dbg !9
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CAccess.Main(ptr sret({ i32, i32 }) %return, ptr %d) !dbg !10 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CAccess.Main(ptr sret({ i32, i32 }) %return, ptr %d) #0 !dbg !10 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc28_12.1.d = getelementptr inbounds nuw { { i32 }, i32 }, ptr %d, i32 0, i32 1, !dbg !11
 // CHECK:STDOUT:   %.loc28_12.2 = load i32, ptr %.loc28_12.1.d, align 4, !dbg !11
@@ -60,16 +62,18 @@ fn Convert(p: Derived*) -> Base* {
 // CHECK:STDOUT:   ret void, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define ptr @_CConvert.Main(ptr %p) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define ptr @_CConvert.Main(ptr %p) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc32_11.2.base = getelementptr inbounds nuw { { i32 }, i32 }, ptr %p, i32 0, i32 0, !dbg !16
 // CHECK:STDOUT:   ret ptr %.loc32_11.2.base, !dbg !16
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #0
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/class/basic.carbon

@@ -27,7 +27,8 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CF.Main(ptr sret({ i32, ptr }), ptr)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %c.var = alloca { i32, ptr }, align 8, !dbg !7
 // CHECK:STDOUT:   %d.var = alloca { i32, ptr }, align 8, !dbg !8
@@ -38,12 +39,13 @@ fn Run() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/class/convert.carbon

@@ -30,19 +30,22 @@ fn DoIt() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @IntWrapper.val.loc24_3 = internal constant { i32 } { i32 42 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @"_CConvert.IntWrapper.Main:ImplicitAs.Core"(ptr %self) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @"_CConvert.IntWrapper.Main:ImplicitAs.Core"(ptr %self) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc18_48.1.n = getelementptr inbounds nuw { i32 }, ptr %self, i32 0, i32 0, !dbg !7
 // CHECK:STDOUT:   %.loc18_48.2 = load i32, ptr %.loc18_48.1.n, align 4, !dbg !7
 // CHECK:STDOUT:   ret i32 %.loc18_48.2, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CConsume.Main(i32 %n) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CConsume.Main(i32 %n) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !10
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CDoIt.Main() !dbg !11 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CDoIt.Main() #0 !dbg !11 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %w.var = alloca { i32 }, align 8, !dbg !12
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %w.var), !dbg !12
@@ -54,13 +57,14 @@ fn DoIt() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/class/field.carbon

@@ -71,7 +71,8 @@ fn Run() {
 // CHECK:STDOUT: ; ModuleID = 'basic.carbon'
 // CHECK:STDOUT: source_filename = "basic.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CF.Main(ptr %c) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CF.Main(ptr %c) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc10_13.1.b = getelementptr inbounds nuw { i32, ptr }, ptr %c, i32 0, i32 1, !dbg !7
 // CHECK:STDOUT:   %.loc10_13.2 = load ptr, ptr %.loc10_13.1.b, align 8, !dbg !7
@@ -80,7 +81,8 @@ fn Run() {
 // CHECK:STDOUT:   ret i32 %.loc10_16.2, !dbg !9
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @main() !dbg !10 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @main() #0 !dbg !10 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %c.var = alloca { i32, ptr }, align 8, !dbg !11
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %c.var), !dbg !11
@@ -93,9 +95,10 @@ fn Run() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
@@ -121,7 +124,8 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @Other.val.loc15_33.5 = internal constant {} zeroinitializer
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %o.var = alloca {}, align 8, !dbg !7
 // CHECK:STDOUT:   %u.var = alloca { ptr, {} }, align 8, !dbg !8
@@ -135,16 +139,17 @@ fn Run() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
@@ -165,7 +170,8 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @Other.val.loc17_40.5 = internal constant { i32 } { i32 42 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %o.var = alloca { i32 }, align 8, !dbg !7
 // CHECK:STDOUT:   %u.var = alloca { ptr, { i32 } }, align 8, !dbg !8
@@ -180,16 +186,17 @@ fn Run() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/class/generic.carbon

@@ -117,7 +117,8 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @Derived.val.loc7_36 = internal constant { { i32 }, i32 } { { i32 } { i32 1 }, i32 2 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CCreateDerived.Create(ptr sret({ { i32 }, i32 }) %return) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CCreateDerived.Create(ptr sret({ { i32 }, i32 }) %return) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc7_35.2.base = getelementptr inbounds nuw { { i32 }, i32 }, ptr %return, i32 0, i32 0, !dbg !7
 // CHECK:STDOUT:   %.loc7_26.3.b = getelementptr inbounds nuw { i32 }, ptr %.loc7_35.2.base, i32 0, i32 0, !dbg !8
@@ -126,16 +127,18 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT:   ret void, !dbg !9
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CCreateAdapter.Create(ptr sret({ { i32 }, i32 }) %return) !dbg !10 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CCreateAdapter.Create(ptr sret({ { i32 }, i32 }) %return) #0 !dbg !10 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CCreateDerived.Create(ptr %return), !dbg !11
 // CHECK:STDOUT:   ret void, !dbg !12
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #0
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
@@ -158,25 +161,29 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @tuple.loc22_28.6 = internal constant { i32, i32 } { i32 1, i32 2 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CInts.Main(ptr sret({ i32, i32 }) %return) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CInts.Main(ptr sret({ i32, i32 }) %return) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CMake.Main.5450dc8e8b8e0899(ptr %return, i32 1, i32 2), !dbg !7
 // CHECK:STDOUT:   ret void, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CEmpty.Main(ptr sret({ {}, {} }) %return) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CEmpty.Main(ptr sret({ {}, {} }) %return) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CMake.Main.cf13cead63317d44(ptr %return), !dbg !10
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTuples.Main(ptr sret({ { i32, i32 }, { i32, i32 } }) %return) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTuples.Main(ptr sret({ { i32, i32 }, { i32, i32 } }) %return) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CMake.Main.a862d5c8b748242e(ptr %return, ptr @tuple.loc22_28.6, ptr @tuple.loc22_28.6), !dbg !13
 // CHECK:STDOUT:   ret void, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CMake.Main.5450dc8e8b8e0899(ptr sret({ i32, i32 }) %return, i32 %x, i32 %y) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CMake.Main.5450dc8e8b8e0899(ptr sret({ i32, i32 }) %return, i32 %x, i32 %y) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc10_25.2.x = getelementptr inbounds nuw { i32, i32 }, ptr %return, i32 0, i32 0, !dbg !16
 // CHECK:STDOUT:   store i32 %x, ptr %.loc10_25.2.x, align 4, !dbg !16
@@ -185,14 +192,16 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT:   ret void, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CMake.Main.cf13cead63317d44(ptr sret({ {}, {} }) %return) !dbg !18 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CMake.Main.cf13cead63317d44(ptr sret({ {}, {} }) %return) #0 !dbg !18 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc10_25.2.x = getelementptr inbounds nuw { {}, {} }, ptr %return, i32 0, i32 0, !dbg !19
 // CHECK:STDOUT:   %.loc10_25.4.y = getelementptr inbounds nuw { {}, {} }, ptr %return, i32 0, i32 1, !dbg !19
 // CHECK:STDOUT:   ret void, !dbg !20
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CMake.Main.a862d5c8b748242e(ptr sret({ { i32, i32 }, { i32, i32 } }) %return, ptr %x, ptr %y) !dbg !21 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CMake.Main.a862d5c8b748242e(ptr sret({ { i32, i32 }, { i32, i32 } }) %return, ptr %x, ptr %y) #0 !dbg !21 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc10_25.2.x = getelementptr inbounds nuw { { i32, i32 }, { i32, i32 } }, ptr %return, i32 0, i32 0, !dbg !22
 // CHECK:STDOUT:   call void @"_COp.2b3ba83e01542f11:Copy.Core.4193728889277ad1"(ptr %.loc10_25.2.x, ptr %x), !dbg !23
@@ -201,7 +210,8 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT:   ret void, !dbg !25
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_COp.2b3ba83e01542f11:Copy.Core.4193728889277ad1"(ptr sret({ i32, i32 }) %return, ptr %self) !dbg !26 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_COp.2b3ba83e01542f11:Copy.Core.4193728889277ad1"(ptr sret({ i32, i32 }) %return, ptr %self) #0 !dbg !26 {
 // CHECK:STDOUT:   %tuple.elem = getelementptr inbounds nuw { i32, i32 }, ptr %self, i32 0, i32 0, !dbg !28
 // CHECK:STDOUT:   %tuple.elem.load = load i32, ptr %tuple.elem, align 4, !dbg !28
 // CHECK:STDOUT:   %tuple.elem1 = getelementptr inbounds nuw { i32, i32 }, ptr %return, i32 0, i32 0, !dbg !29
@@ -216,6 +226,8 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @"_COp.2b3ba83e01542f11:Copy.Core.4193728889277ad1", { 1, 0 }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:
@@ -258,7 +270,8 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT: @C.val.f52.loc26_3 = internal constant { i1, {} } { i1 true, {} zeroinitializer }
 // CHECK:STDOUT: @C.val.029.loc31_3 = internal constant { i1, { i32, i32, i32 } } { i1 true, { i32, i32, i32 } { i32 1, i32 2, i32 3 } }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @_CAccessBool.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @_CAccessBool.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %c.var = alloca { i1, i32 }, align 8, !dbg !7
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %c.var), !dbg !7
@@ -269,7 +282,8 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT:   ret i1 %C.GetBool.call, !dbg !10
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CAccessInt.Main() !dbg !11 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CAccessInt.Main() #0 !dbg !11 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %c.var = alloca { i1, i32 }, align 8, !dbg !12
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %c.var), !dbg !12
@@ -280,7 +294,8 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT:   ret i32 %C.GetT.call, !dbg !15
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CAccessEmpty.Main() !dbg !16 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CAccessEmpty.Main() #0 !dbg !16 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %c.var = alloca { i1, {} }, align 8, !dbg !17
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %c.var), !dbg !17
@@ -291,7 +306,8 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT:   ret void, !dbg !20
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CAccessTuple.Main(ptr sret({ i32, i32, i32 }) %return) !dbg !21 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CAccessTuple.Main(ptr sret({ i32, i32, i32 }) %return) #0 !dbg !21 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %c.var = alloca { i1, { i32, i32, i32 } }, align 8, !dbg !22
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %c.var), !dbg !22
@@ -306,12 +322,13 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i1 @_CGetBool.C.Main.5450dc8e8b8e0899(ptr %self) !dbg !27 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i1 @_CGetBool.C.Main.5450dc8e8b8e0899(ptr %self) #0 !dbg !27 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc6_16.1.v = getelementptr inbounds nuw { i1, i32 }, ptr %self, i32 0, i32 0, !dbg !28
 // CHECK:STDOUT:   %.loc6_16.2 = load i8, ptr %.loc6_16.1.v, align 1, !dbg !28
@@ -319,27 +336,31 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT:   ret i1 %.loc6_16.21, !dbg !29
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CGetT.C.Main.5450dc8e8b8e0899(ptr %self) !dbg !30 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CGetT.C.Main.5450dc8e8b8e0899(ptr %self) #0 !dbg !30 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc9_16.1.w = getelementptr inbounds nuw { i1, i32 }, ptr %self, i32 0, i32 1, !dbg !31
 // CHECK:STDOUT:   %.loc9_16.2 = load i32, ptr %.loc9_16.1.w, align 4, !dbg !31
 // CHECK:STDOUT:   ret i32 %.loc9_16.2, !dbg !32
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CGetT.C.Main.cf13cead63317d44(ptr %self) !dbg !33 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CGetT.C.Main.cf13cead63317d44(ptr %self) #0 !dbg !33 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc9_16.1.w = getelementptr inbounds nuw { i1, {} }, ptr %self, i32 0, i32 1, !dbg !34
 // CHECK:STDOUT:   ret void, !dbg !35
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CGetT.C.Main.623a49e5eda7ec3b(ptr sret({ i32, i32, i32 }) %return, ptr %self) !dbg !36 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CGetT.C.Main.623a49e5eda7ec3b(ptr sret({ i32, i32, i32 }) %return, ptr %self) #0 !dbg !36 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc9_16.1.w = getelementptr inbounds nuw { i1, { i32, i32, i32 } }, ptr %self, i32 0, i32 1, !dbg !37
 // CHECK:STDOUT:   call void @"_COp.6d582b60b7397ec5:Copy.Core.8e95c89adba3b450"(ptr %return, ptr %.loc9_16.1.w), !dbg !37
 // CHECK:STDOUT:   ret void, !dbg !38
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_COp.6d582b60b7397ec5:Copy.Core.8e95c89adba3b450"(ptr sret({ i32, i32, i32 }) %return, ptr %self) !dbg !39 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_COp.6d582b60b7397ec5:Copy.Core.8e95c89adba3b450"(ptr sret({ i32, i32, i32 }) %return, ptr %self) #0 !dbg !39 {
 // CHECK:STDOUT:   %tuple.elem = getelementptr inbounds nuw { i32, i32, i32 }, ptr %self, i32 0, i32 0, !dbg !41
 // CHECK:STDOUT:   %tuple.elem.load = load i32, ptr %tuple.elem, align 4, !dbg !41
 // CHECK:STDOUT:   %tuple.elem1 = getelementptr inbounds nuw { i32, i32, i32 }, ptr %return, i32 0, i32 0, !dbg !42
@@ -359,8 +380,9 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 3, 2, 1, 0 }
 // CHECK:STDOUT: uselistorder ptr @llvm.memcpy.p0.p0.i64, { 3, 2, 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/class/import.carbon

@@ -42,7 +42,8 @@ fn Run() {
 // CHECK:STDOUT: ; ModuleID = 'b.carbon'
 // CHECK:STDOUT: source_filename = "b.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CF.C.Main(), !dbg !7
 // CHECK:STDOUT:   ret void, !dbg !8
@@ -50,6 +51,8 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CF.C.Main()
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/class/method.carbon

@@ -29,13 +29,16 @@ fn F(p: C*) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CSet.C.Main(ptr, i32)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main(ptr %p) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main(ptr %p) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %C.Get.call = call i32 @_CGet.C.Main(ptr %p), !dbg !7
 // CHECK:STDOUT:   call void @_CSet.C.Main(ptr %p, i32 %C.Get.call), !dbg !8
 // CHECK:STDOUT:   ret void, !dbg !9
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/class/method_addr.carbon

@@ -29,13 +29,16 @@ fn F(p: C*) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CSet.C.Main(ptr, i32)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main(ptr %p) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main(ptr %p) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %C.Get.call = call i32 @_CGet.C.Main(ptr %p), !dbg !7
 // CHECK:STDOUT:   call void @_CSet.C.Main(ptr %p, i32 %C.Get.call), !dbg !8
 // CHECK:STDOUT:   ret void, !dbg !9
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/class/self.carbon

@@ -28,20 +28,24 @@ fn C.Set[ref self: C]() {
 // CHECK:STDOUT: ; ModuleID = 'self.carbon'
 // CHECK:STDOUT: source_filename = "self.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CGet.C.Main(ptr %self) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CGet.C.Main(ptr %self) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc21_14.1.a = getelementptr inbounds nuw { i32 }, ptr %self, i32 0, i32 0, !dbg !7
 // CHECK:STDOUT:   %.loc21_14.2 = load i32, ptr %.loc21_14.1.a, align 4, !dbg !7
 // CHECK:STDOUT:   ret i32 %.loc21_14.2, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CSet.C.Main(ptr %self) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CSet.C.Main(ptr %self) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc25_7.a = getelementptr inbounds nuw { i32 }, ptr %self, i32 0, i32 0, !dbg !10
 // CHECK:STDOUT:   store i32 1, ptr %.loc25_7.a, align 4, !dbg !10
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/class/self_addr.carbon

@@ -28,20 +28,24 @@ fn C.Set[addr self: C*]() {
 // CHECK:STDOUT: ; ModuleID = 'self_addr.carbon'
 // CHECK:STDOUT: source_filename = "self_addr.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CGet.C.Main(ptr %self) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CGet.C.Main(ptr %self) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc21_14.1.a = getelementptr inbounds nuw { i32 }, ptr %self, i32 0, i32 0, !dbg !7
 // CHECK:STDOUT:   %.loc21_14.2 = load i32, ptr %.loc21_14.1.a, align 4, !dbg !7
 // CHECK:STDOUT:   ret i32 %.loc21_14.2, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CSet.C.Main(ptr %self) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CSet.C.Main(ptr %self) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc25_10.a = getelementptr inbounds nuw { i32 }, ptr %self, i32 0, i32 0, !dbg !10
 // CHECK:STDOUT:   store i32 1, ptr %.loc25_10.a, align 4, !dbg !10
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/class/value_access.carbon

@@ -24,7 +24,8 @@ fn F(c: C) -> i32 {
 // CHECK:STDOUT: ; ModuleID = 'value_access.carbon'
 // CHECK:STDOUT: source_filename = "value_access.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CF.Main(ptr %c) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CF.Main(ptr %c) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc21_11.1.a = getelementptr inbounds nuw { { i32, i32, i32 } }, ptr %c, i32 0, i32 0, !dbg !7
 // CHECK:STDOUT:   %tuple.elem0.tuple.elem = getelementptr inbounds nuw { i32, i32, i32 }, ptr %.loc21_11.1.a, i32 0, i32 0, !dbg !7
@@ -45,6 +46,8 @@ fn F(c: C) -> i32 {
 // CHECK:STDOUT:   ret i32 %tuple.elem1.loc21_13.tuple.elem.load, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/class/virtual.carbon

@@ -160,16 +160,20 @@ fn Make() {
 // CHECK:STDOUT: @"_CIntermediate.Classes.$vtable" = unnamed_addr constant [1 x i32] [i32 trunc (i64 sub (i64 ptrtoint (ptr @_CFn.Intermediate.Classes to i64), i64 ptrtoint (ptr @"_CIntermediate.Classes.$vtable" to i64)) to i32)]
 // CHECK:STDOUT: @"_CDerived.Classes.$vtable" = unnamed_addr constant [1 x i32] [i32 trunc (i64 sub (i64 ptrtoint (ptr @_CFn.Derived.Classes to i64), i64 ptrtoint (ptr @"_CDerived.Classes.$vtable" to i64)) to i32)]
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFn.Intermediate.Classes(ptr %self) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFn.Intermediate.Classes(ptr %self) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFn.Derived.Classes(ptr %self) !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFn.Derived.Classes(ptr %self) #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !9
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:
@@ -192,7 +196,8 @@ fn Make() {
 // CHECK:STDOUT: @Intermediate.val.ec2.loc8_3 = internal constant { ptr, {} } { ptr @"_CIntermediate.Classes.$vtable", {} zeroinitializer }
 // CHECK:STDOUT: @Derived.val.loc9_3 = internal constant { { ptr, {} } } { { ptr, {} } { ptr @"_CDerived.Classes.$vtable", {} zeroinitializer } }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CCreate.Create() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CCreate.Create() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %b.var = alloca {}, align 8, !dbg !7
 // CHECK:STDOUT:   %i.var = alloca { ptr, {} }, align 8, !dbg !8
@@ -217,7 +222,8 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CFn.Derived.Classes(ptr)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CUse.Create(ptr %v) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CUse.Create(ptr %v) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Intermediate.Fn.call.vtable = load ptr, ptr %v, align 8, !dbg !16
 // CHECK:STDOUT:   %Intermediate.Fn.call = call ptr @llvm.load.relative.i32(ptr %Intermediate.Fn.call.vtable, i32 0), !dbg !16
@@ -226,21 +232,22 @@ fn Make() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: read)
-// CHECK:STDOUT: declare ptr @llvm.load.relative.i32(ptr, i32) #2
+// CHECK:STDOUT: declare ptr @llvm.load.relative.i32(ptr, i32) #3
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 3, 2, 1, 0 }
 // CHECK:STDOUT: uselistorder ptr @llvm.memcpy.p0.p0.i64, { 2, 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: read) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #3 = { nocallback nofree nosync nounwind willreturn memory(argmem: read) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
@@ -269,12 +276,14 @@ fn Make() {
 // CHECK:STDOUT: @"_CBase.MemberInit.$vtable" = unnamed_addr constant [1 x i32] [i32 trunc (i64 sub (i64 ptrtoint (ptr @_CFn.Base.MemberInit to i64), i64 ptrtoint (ptr @"_CBase.MemberInit.$vtable" to i64)) to i32)]
 // CHECK:STDOUT: @Base.val.loc13_3 = internal constant { ptr, i32 } { ptr @"_CBase.MemberInit.$vtable", i32 3 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFn.Base.MemberInit(ptr %self) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFn.Base.MemberInit(ptr %self) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFn.MemberInit() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFn.MemberInit() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %i.var = alloca i32, align 4, !dbg !9
 // CHECK:STDOUT:   %v.var = alloca { ptr, i32 }, align 8, !dbg !10
@@ -297,16 +306,17 @@ fn Make() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 2, 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
@@ -337,7 +347,8 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CF.Base.Main(ptr)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CUse.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CUse.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %v.var = alloca { { ptr } }, align 8, !dbg !7
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %v.var), !dbg !7
@@ -348,13 +359,14 @@ fn Make() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
@@ -377,7 +389,8 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CF.Base.Main(ptr)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CUse.Main(ptr %b) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CUse.Main(ptr %b) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Base.F.call.vtable = load ptr, ptr %b, align 8, !dbg !7
 // CHECK:STDOUT:   %Base.F.call = call ptr @llvm.load.relative.i32(ptr %Base.F.call.vtable, i32 0), !dbg !7
@@ -386,9 +399,10 @@ fn Make() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: read)
-// CHECK:STDOUT: declare ptr @llvm.load.relative.i32(ptr, i32) #0
+// CHECK:STDOUT: declare ptr @llvm.load.relative.i32(ptr, i32) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: read) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: read) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
@@ -413,7 +427,8 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CF.Derived.Main(ptr)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CUse.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CUse.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %v.var = alloca { { ptr } }, align 8, !dbg !7
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %v.var), !dbg !7
@@ -427,17 +442,18 @@ fn Make() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: read)
-// CHECK:STDOUT: declare ptr @llvm.load.relative.i32(ptr, i32) #2
+// CHECK:STDOUT: declare ptr @llvm.load.relative.i32(ptr, i32) #3
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: read) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #3 = { nocallback nofree nosync nounwind willreturn memory(argmem: read) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
@@ -472,7 +488,8 @@ fn Make() {
 // CHECK:STDOUT: @Base.val.58c.loc16_3 = internal constant { ptr } { ptr @"_CBase.Main.$vtable.b29a32b2b49cc0f3" }
 // CHECK:STDOUT: @Base.val.a96.loc17_3 = internal constant { ptr } { ptr @"_CBase.Main.$vtable.aa6c84e7fdd60e03" }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %t1.var = alloca { ptr }, align 8, !dbg !7
 // CHECK:STDOUT:   %t2.var = alloca { ptr }, align 8, !dbg !8
@@ -485,14 +502,16 @@ fn Make() {
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Base.Main.b29a32b2b49cc0f3(ptr %self) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Base.Main.b29a32b2b49cc0f3(ptr %self) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %v.var = alloca {}, align 8, !dbg !13
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %v.var), !dbg !13
 // CHECK:STDOUT:   ret void, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Base.Main.aa6c84e7fdd60e03(ptr %self) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Base.Main.aa6c84e7fdd60e03(ptr %self) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %v.var = alloca { {} }, align 8, !dbg !16
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %v.var), !dbg !16
@@ -500,17 +519,18 @@ fn Make() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 3, 2, 1, 0 }
 // CHECK:STDOUT: uselistorder ptr @llvm.memcpy.p0.p0.i64, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
@@ -538,22 +558,25 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @"_CDerived.Main.$vtable" = unnamed_addr constant [1 x i32] [i32 trunc (i64 sub (i64 ptrtoint (ptr @_CF.Base.Main.4d2ffa01ebfb7a1d to i64), i64 ptrtoint (ptr @"_CDerived.Main.$vtable" to i64)) to i32)]
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMake.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMake.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %v.var = alloca { { ptr } }, align 8, !dbg !7
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %v.var), !dbg !7
 // CHECK:STDOUT:   ret void, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Base.Main.4d2ffa01ebfb7a1d(ptr %self) !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Base.Main.4d2ffa01ebfb7a1d(ptr %self) #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !10
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/debug/nodebug.carbon

@@ -17,7 +17,10 @@ fn F() {
 // CHECK:STDOUT: ; ModuleID = 'nodebug.carbon'
 // CHECK:STDOUT: source_filename = "nodebug.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main() {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main() #0 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void
 // CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }

toolchain/lower/testdata/for/bindings.carbon

@@ -38,7 +38,8 @@ fn For() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CF.Main(i32, ptr)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFor.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFor.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %r.var = alloca {}, align 8, !dbg !7
 // CHECK:STDOUT:   %var = alloca {}, align 8, !dbg !8
@@ -74,57 +75,66 @@ fn For() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_CNewCursor.EmptyRange.Main:Iterate.Core.a862d5c8b748242e"(ptr %self) !dbg !13 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CNewCursor.EmptyRange.Main:Iterate.Core.a862d5c8b748242e"(ptr %self) #0 !dbg !13 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_CNext.EmptyRange.Main:Iterate.Core.a862d5c8b748242e"(ptr sret({ { i32, i32 }, i1 }) %return, ptr %self, ptr %cursor) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CNext.EmptyRange.Main:Iterate.Core.a862d5c8b748242e"(ptr sret({ { i32, i32 }, i1 }) %return, ptr %self, ptr %cursor) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CNone.Optional.Core.7a2fd2277130880e(ptr %return), !dbg !16
 // CHECK:STDOUT:   ret void, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i1 @_CHasValue.Optional.Core.7a2fd2277130880e(ptr %self) !dbg !18 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i1 @_CHasValue.Optional.Core.7a2fd2277130880e(ptr %self) #0 !dbg !18 {
 // CHECK:STDOUT:   %1 = call i1 @"_CHas.225258f1a45e9386:OptionalStorage.Core.a862d5c8b748242e"(ptr %self), !dbg !20
 // CHECK:STDOUT:   ret i1 %1, !dbg !21
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CGet.Optional.Core.7a2fd2277130880e(ptr sret({ i32, i32 }) %return, ptr %self) !dbg !22 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CGet.Optional.Core.7a2fd2277130880e(ptr sret({ i32, i32 }) %return, ptr %self) #0 !dbg !22 {
 // CHECK:STDOUT:   call void @"_CGet.225258f1a45e9386:OptionalStorage.Core.a862d5c8b748242e"(ptr %return, ptr %self), !dbg !23
 // CHECK:STDOUT:   ret void, !dbg !24
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CNone.Optional.Core.7a2fd2277130880e(ptr sret({ { i32, i32 }, i1 }) %return) !dbg !25 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CNone.Optional.Core.7a2fd2277130880e(ptr sret({ { i32, i32 }, i1 }) %return) #0 !dbg !25 {
 // CHECK:STDOUT:   call void @"_CNone.225258f1a45e9386:OptionalStorage.Core.a862d5c8b748242e"(ptr %return), !dbg !26
 // CHECK:STDOUT:   ret void, !dbg !27
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i1 @"_CHas.225258f1a45e9386:OptionalStorage.Core.a862d5c8b748242e"(ptr %value) !dbg !28 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i1 @"_CHas.225258f1a45e9386:OptionalStorage.Core.a862d5c8b748242e"(ptr %value) #0 !dbg !28 {
 // CHECK:STDOUT:   %has_value = getelementptr inbounds nuw { { i32, i32 }, i1 }, ptr %value, i32 0, i32 1, !dbg !29
 // CHECK:STDOUT:   %1 = load i8, ptr %has_value, align 1, !dbg !29
 // CHECK:STDOUT:   %2 = trunc i8 %1 to i1, !dbg !29
 // CHECK:STDOUT:   ret i1 %2, !dbg !30
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_CGet.225258f1a45e9386:OptionalStorage.Core.a862d5c8b748242e"(ptr sret({ i32, i32 }) %return, ptr %value) !dbg !31 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CGet.225258f1a45e9386:OptionalStorage.Core.a862d5c8b748242e"(ptr sret({ i32, i32 }) %return, ptr %value) #0 !dbg !31 {
 // CHECK:STDOUT:   %value1 = getelementptr inbounds nuw { { i32, i32 }, i1 }, ptr %value, i32 0, i32 0, !dbg !32
 // CHECK:STDOUT:   call void @"_COp.2b3ba83e01542f11:Copy.Core.4193728889277ad1"(ptr %return, ptr %value1), !dbg !32
 // CHECK:STDOUT:   ret void, !dbg !33
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_CNone.225258f1a45e9386:OptionalStorage.Core.a862d5c8b748242e"(ptr sret({ { i32, i32 }, i1 }) %return) !dbg !34 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CNone.225258f1a45e9386:OptionalStorage.Core.a862d5c8b748242e"(ptr sret({ { i32, i32 }, i1 }) %return) #0 !dbg !34 {
 // CHECK:STDOUT:   %has_value = getelementptr inbounds nuw { { i32, i32 }, i1 }, ptr %return, i32 0, i32 1, !dbg !35
 // CHECK:STDOUT:   store i8 0, ptr %has_value, align 1, !dbg !35
 // CHECK:STDOUT:   ret void, !dbg !36
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_COp.2b3ba83e01542f11:Copy.Core.4193728889277ad1"(ptr sret({ i32, i32 }) %return, ptr %self) !dbg !37 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_COp.2b3ba83e01542f11:Copy.Core.4193728889277ad1"(ptr sret({ i32, i32 }) %return, ptr %self) #0 !dbg !37 {
 // CHECK:STDOUT:   %tuple.elem = getelementptr inbounds nuw { i32, i32 }, ptr %self, i32 0, i32 0, !dbg !39
 // CHECK:STDOUT:   %tuple.elem.load = load i32, ptr %tuple.elem, align 4, !dbg !39
 // CHECK:STDOUT:   %tuple.elem1 = getelementptr inbounds nuw { i32, i32 }, ptr %return, i32 0, i32 0, !dbg !40
@@ -139,8 +149,9 @@ fn For() {
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 4, 3, 2, 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/for/break_continue.carbon

@@ -33,7 +33,8 @@ fn For() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CH.Main()
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFor.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFor.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc20_32.1.temp = alloca { i32, i32 }, align 8, !dbg !7
 // CHECK:STDOUT:   %var = alloca i32, align 4, !dbg !8
@@ -77,15 +78,17 @@ fn For() {
 // CHECK:STDOUT: declare void @_CRange.Core(ptr sret({ i32, i32 }), i32)
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @"_CNewCursor.IntRange.Core:Iterate.Core.be1e879c1ad406d8"(ptr %self) !dbg !18 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @"_CNewCursor.IntRange.Core:Iterate.Core.be1e879c1ad406d8"(ptr %self) #0 !dbg !18 {
 // CHECK:STDOUT:   %start = getelementptr inbounds nuw { i32, i32 }, ptr %self, i32 0, i32 0, !dbg !20
 // CHECK:STDOUT:   %1 = load i32, ptr %start, align 4, !dbg !20
 // CHECK:STDOUT:   ret i32 %1, !dbg !21
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_CNext.IntRange.Core:Iterate.Core.be1e879c1ad406d8"(ptr sret({ i32, i1 }) %return, ptr %self, ptr %cursor) !dbg !22 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CNext.IntRange.Core:Iterate.Core.be1e879c1ad406d8"(ptr sret({ i32, i1 }) %return, ptr %self, ptr %cursor) #0 !dbg !22 {
 // CHECK:STDOUT:   %1 = alloca i32, align 4, !dbg !23
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %1), !dbg !23
 // CHECK:STDOUT:   %2 = load i32, ptr %cursor, align 4, !dbg !24
@@ -107,47 +110,55 @@ fn For() {
 // CHECK:STDOUT:   ret void, !dbg !33
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i1 @_CHasValue.Optional.Core.c1b882a73b8b9531(ptr %self) !dbg !34 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i1 @_CHasValue.Optional.Core.c1b882a73b8b9531(ptr %self) #0 !dbg !34 {
 // CHECK:STDOUT:   %1 = call i1 @"_CHas.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %self), !dbg !36
 // CHECK:STDOUT:   ret i1 %1, !dbg !37
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CGet.Optional.Core.c1b882a73b8b9531(ptr %self) !dbg !38 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CGet.Optional.Core.c1b882a73b8b9531(ptr %self) #0 !dbg !38 {
 // CHECK:STDOUT:   %1 = call i32 @"_CGet.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %self), !dbg !39
 // CHECK:STDOUT:   ret i32 %1, !dbg !40
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CInclusiveRange.Core(ptr sret({ i32, i32 }), i32, i32)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_COp.Int.Core:Inc.Core.be1e879c1ad406d8"(ptr %self) !dbg !41 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_COp.Int.Core:Inc.Core.be1e879c1ad406d8"(ptr %self) #0 !dbg !41 {
 // CHECK:STDOUT:   call void @"_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e"(ptr %self, i32 1), !dbg !43
 // CHECK:STDOUT:   ret void, !dbg !44
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CSome.Optional.Core.c1b882a73b8b9531(ptr sret({ i32, i1 }) %return, i32 %value) !dbg !45 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CSome.Optional.Core.c1b882a73b8b9531(ptr sret({ i32, i1 }) %return, i32 %value) #0 !dbg !45 {
 // CHECK:STDOUT:   call void @"_CSome.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %return, i32 %value), !dbg !46
 // CHECK:STDOUT:   ret void, !dbg !47
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CNone.Optional.Core.c1b882a73b8b9531(ptr sret({ i32, i1 }) %return) !dbg !48 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CNone.Optional.Core.c1b882a73b8b9531(ptr sret({ i32, i1 }) %return) #0 !dbg !48 {
 // CHECK:STDOUT:   call void @"_CNone.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %return), !dbg !49
 // CHECK:STDOUT:   ret void, !dbg !50
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i1 @"_CHas.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %value) !dbg !51 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i1 @"_CHas.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %value) #0 !dbg !51 {
 // CHECK:STDOUT:   %has_value = getelementptr inbounds nuw { i32, i1 }, ptr %value, i32 0, i32 1, !dbg !52
 // CHECK:STDOUT:   %1 = load i8, ptr %has_value, align 1, !dbg !52
 // CHECK:STDOUT:   %2 = trunc i8 %1 to i1, !dbg !52
 // CHECK:STDOUT:   ret i1 %2, !dbg !53
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @"_CGet.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %value) !dbg !54 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @"_CGet.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %value) #0 !dbg !54 {
 // CHECK:STDOUT:   %value1 = getelementptr inbounds nuw { i32, i1 }, ptr %value, i32 0, i32 0, !dbg !55
 // CHECK:STDOUT:   %1 = load i32, ptr %value1, align 4, !dbg !55
 // CHECK:STDOUT:   ret i32 %1, !dbg !56
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e"(ptr %self, i32 %other) !dbg !57 {
+// CHECK:STDOUT: ; Function Attrs: alwaysinline nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e"(ptr %self, i32 %other) #2 !dbg !57 {
 // CHECK:STDOUT:   %1 = call i32 @"_CConvert.225258f1a45e9386:ImplicitAs.Core.5450dc8e8b8e0899"(i32 %other), !dbg !58
 // CHECK:STDOUT:   %2 = load i32, ptr %self, align 4, !dbg !59
 // CHECK:STDOUT:   %3 = add i32 %2, %1, !dbg !59
@@ -155,7 +166,8 @@ fn For() {
 // CHECK:STDOUT:   ret void, !dbg !59
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_CSome.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr sret({ i32, i1 }) %return, i32 %self) !dbg !60 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CSome.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr sret({ i32, i1 }) %return, i32 %self) #0 !dbg !60 {
 // CHECK:STDOUT:   %value = getelementptr inbounds nuw { i32, i1 }, ptr %return, i32 0, i32 0, !dbg !61
 // CHECK:STDOUT:   store i32 %self, ptr %value, align 4, !dbg !61
 // CHECK:STDOUT:   %has_value = getelementptr inbounds nuw { i32, i1 }, ptr %return, i32 0, i32 1, !dbg !62
@@ -163,20 +175,24 @@ fn For() {
 // CHECK:STDOUT:   ret void, !dbg !63
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_CNone.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr sret({ i32, i1 }) %return) !dbg !64 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CNone.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr sret({ i32, i1 }) %return) #0 !dbg !64 {
 // CHECK:STDOUT:   %has_value = getelementptr inbounds nuw { i32, i1 }, ptr %return, i32 0, i32 1, !dbg !65
 // CHECK:STDOUT:   store i8 0, ptr %has_value, align 1, !dbg !65
 // CHECK:STDOUT:   ret void, !dbg !66
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @"_CConvert.225258f1a45e9386:ImplicitAs.Core.5450dc8e8b8e0899"(i32 %self) !dbg !67 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @"_CConvert.225258f1a45e9386:ImplicitAs.Core.5450dc8e8b8e0899"(i32 %self) #0 !dbg !67 {
 // CHECK:STDOUT:   ret i32 %self, !dbg !69
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 0, 3, 2, 1 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { alwaysinline nounwind }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/for/for.carbon

@@ -33,7 +33,8 @@ fn For() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CH.Main()
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFor.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFor.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc21_32.1.temp = alloca { i32, i32 }, align 8, !dbg !7
 // CHECK:STDOUT:   %var = alloca i32, align 4, !dbg !8
@@ -65,15 +66,17 @@ fn For() {
 // CHECK:STDOUT: declare void @_CRange.Core(ptr sret({ i32, i32 }), i32)
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @"_CNewCursor.IntRange.Core:Iterate.Core.be1e879c1ad406d8"(ptr %self) !dbg !14 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @"_CNewCursor.IntRange.Core:Iterate.Core.be1e879c1ad406d8"(ptr %self) #0 !dbg !14 {
 // CHECK:STDOUT:   %start = getelementptr inbounds nuw { i32, i32 }, ptr %self, i32 0, i32 0, !dbg !16
 // CHECK:STDOUT:   %1 = load i32, ptr %start, align 4, !dbg !16
 // CHECK:STDOUT:   ret i32 %1, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_CNext.IntRange.Core:Iterate.Core.be1e879c1ad406d8"(ptr sret({ i32, i1 }) %return, ptr %self, ptr %cursor) !dbg !18 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CNext.IntRange.Core:Iterate.Core.be1e879c1ad406d8"(ptr sret({ i32, i1 }) %return, ptr %self, ptr %cursor) #0 !dbg !18 {
 // CHECK:STDOUT:   %1 = alloca i32, align 4, !dbg !19
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %1), !dbg !19
 // CHECK:STDOUT:   %2 = load i32, ptr %cursor, align 4, !dbg !20
@@ -95,47 +98,55 @@ fn For() {
 // CHECK:STDOUT:   ret void, !dbg !29
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i1 @_CHasValue.Optional.Core.c1b882a73b8b9531(ptr %self) !dbg !30 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i1 @_CHasValue.Optional.Core.c1b882a73b8b9531(ptr %self) #0 !dbg !30 {
 // CHECK:STDOUT:   %1 = call i1 @"_CHas.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %self), !dbg !32
 // CHECK:STDOUT:   ret i1 %1, !dbg !33
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CGet.Optional.Core.c1b882a73b8b9531(ptr %self) !dbg !34 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CGet.Optional.Core.c1b882a73b8b9531(ptr %self) #0 !dbg !34 {
 // CHECK:STDOUT:   %1 = call i32 @"_CGet.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %self), !dbg !35
 // CHECK:STDOUT:   ret i32 %1, !dbg !36
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CInclusiveRange.Core(ptr sret({ i32, i32 }), i32, i32)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_COp.Int.Core:Inc.Core.be1e879c1ad406d8"(ptr %self) !dbg !37 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_COp.Int.Core:Inc.Core.be1e879c1ad406d8"(ptr %self) #0 !dbg !37 {
 // CHECK:STDOUT:   call void @"_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e"(ptr %self, i32 1), !dbg !39
 // CHECK:STDOUT:   ret void, !dbg !40
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CSome.Optional.Core.c1b882a73b8b9531(ptr sret({ i32, i1 }) %return, i32 %value) !dbg !41 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CSome.Optional.Core.c1b882a73b8b9531(ptr sret({ i32, i1 }) %return, i32 %value) #0 !dbg !41 {
 // CHECK:STDOUT:   call void @"_CSome.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %return, i32 %value), !dbg !42
 // CHECK:STDOUT:   ret void, !dbg !43
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CNone.Optional.Core.c1b882a73b8b9531(ptr sret({ i32, i1 }) %return) !dbg !44 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CNone.Optional.Core.c1b882a73b8b9531(ptr sret({ i32, i1 }) %return) #0 !dbg !44 {
 // CHECK:STDOUT:   call void @"_CNone.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %return), !dbg !45
 // CHECK:STDOUT:   ret void, !dbg !46
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i1 @"_CHas.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %value) !dbg !47 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i1 @"_CHas.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %value) #0 !dbg !47 {
 // CHECK:STDOUT:   %has_value = getelementptr inbounds nuw { i32, i1 }, ptr %value, i32 0, i32 1, !dbg !48
 // CHECK:STDOUT:   %1 = load i8, ptr %has_value, align 1, !dbg !48
 // CHECK:STDOUT:   %2 = trunc i8 %1 to i1, !dbg !48
 // CHECK:STDOUT:   ret i1 %2, !dbg !49
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @"_CGet.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %value) !dbg !50 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @"_CGet.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr %value) #0 !dbg !50 {
 // CHECK:STDOUT:   %value1 = getelementptr inbounds nuw { i32, i1 }, ptr %value, i32 0, i32 0, !dbg !51
 // CHECK:STDOUT:   %1 = load i32, ptr %value1, align 4, !dbg !51
 // CHECK:STDOUT:   ret i32 %1, !dbg !52
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e"(ptr %self, i32 %other) !dbg !53 {
+// CHECK:STDOUT: ; Function Attrs: alwaysinline nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_COp:thunk.Int.Core:AddAssignWith.Core.5dfb78ae56583d8e"(ptr %self, i32 %other) #2 !dbg !53 {
 // CHECK:STDOUT:   %1 = call i32 @"_CConvert.225258f1a45e9386:ImplicitAs.Core.5450dc8e8b8e0899"(i32 %other), !dbg !54
 // CHECK:STDOUT:   %2 = load i32, ptr %self, align 4, !dbg !55
 // CHECK:STDOUT:   %3 = add i32 %2, %1, !dbg !55
@@ -143,7 +154,8 @@ fn For() {
 // CHECK:STDOUT:   ret void, !dbg !55
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_CSome.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr sret({ i32, i1 }) %return, i32 %self) !dbg !56 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CSome.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr sret({ i32, i1 }) %return, i32 %self) #0 !dbg !56 {
 // CHECK:STDOUT:   %value = getelementptr inbounds nuw { i32, i1 }, ptr %return, i32 0, i32 0, !dbg !57
 // CHECK:STDOUT:   store i32 %self, ptr %value, align 4, !dbg !57
 // CHECK:STDOUT:   %has_value = getelementptr inbounds nuw { i32, i1 }, ptr %return, i32 0, i32 1, !dbg !58
@@ -151,20 +163,24 @@ fn For() {
 // CHECK:STDOUT:   ret void, !dbg !59
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @"_CNone.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr sret({ i32, i1 }) %return) !dbg !60 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CNone.225258f1a45e9386:OptionalStorage.Core.5450dc8e8b8e0899"(ptr sret({ i32, i1 }) %return) #0 !dbg !60 {
 // CHECK:STDOUT:   %has_value = getelementptr inbounds nuw { i32, i1 }, ptr %return, i32 0, i32 1, !dbg !61
 // CHECK:STDOUT:   store i8 0, ptr %has_value, align 1, !dbg !61
 // CHECK:STDOUT:   ret void, !dbg !62
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @"_CConvert.225258f1a45e9386:ImplicitAs.Core.5450dc8e8b8e0899"(i32 %self) !dbg !63 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @"_CConvert.225258f1a45e9386:ImplicitAs.Core.5450dc8e8b8e0899"(i32 %self) #0 !dbg !63 {
 // CHECK:STDOUT:   ret i32 %self, !dbg !65
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 0, 3, 2, 1 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { alwaysinline nounwind }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/call/empty_struct.carbon

@@ -21,12 +21,14 @@ fn Main() {
 // CHECK:STDOUT: ; ModuleID = 'empty_struct.carbon'
 // CHECK:STDOUT: source_filename = "empty_struct.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CEcho.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CEcho.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %b.var = alloca {}, align 8, !dbg !9
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %b.var), !dbg !9
@@ -35,9 +37,10 @@ fn Main() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/call/empty_tuple.carbon

@@ -21,12 +21,14 @@ fn Main() {
 // CHECK:STDOUT: ; ModuleID = 'empty_tuple.carbon'
 // CHECK:STDOUT: source_filename = "empty_tuple.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CEcho.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CEcho.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %b.var = alloca {}, align 8, !dbg !9
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %b.var), !dbg !9
@@ -35,9 +37,10 @@ fn Main() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/call/i32.carbon

@@ -21,12 +21,14 @@ fn Main() {
 // CHECK:STDOUT: ; ModuleID = 'i32.carbon'
 // CHECK:STDOUT: source_filename = "i32.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CEcho.Main(i32 %a) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CEcho.Main(i32 %a) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret i32 %a, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %b.var = alloca i32, align 4, !dbg !9
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %b.var), !dbg !9
@@ -36,9 +38,10 @@ fn Main() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/call/implicit_empty_tuple_as_arg.carbon

@@ -22,17 +22,20 @@ fn Main() {
 // CHECK:STDOUT: ; ModuleID = 'implicit_empty_tuple_as_arg.carbon'
 // CHECK:STDOUT: source_filename = "implicit_empty_tuple_as_arg.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFoo.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFoo.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CBar.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CBar.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !9
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !10 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !10 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %x.var = alloca {}, align 8, !dbg !11
 // CHECK:STDOUT:   %.loc19_23.1.temp = alloca {}, align 8, !dbg !12
@@ -44,12 +47,13 @@ fn Main() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/call/params_one.carbon

@@ -19,17 +19,21 @@ fn Main() {
 // CHECK:STDOUT: ; ModuleID = 'params_one.carbon'
 // CHECK:STDOUT: source_filename = "params_one.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFoo.Main(i32 %a) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFoo.Main(i32 %a) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CFoo.Main(i32 1), !dbg !9
 // CHECK:STDOUT:   ret void, !dbg !10
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/call/params_one_comma.carbon

@@ -20,18 +20,22 @@ fn Main() {
 // CHECK:STDOUT: ; ModuleID = 'params_one_comma.carbon'
 // CHECK:STDOUT: source_filename = "params_one_comma.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFoo.Main(i32 %a) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFoo.Main(i32 %a) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CFoo.Main(i32 1), !dbg !9
 // CHECK:STDOUT:   call void @_CFoo.Main(i32 1), !dbg !10
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/call/params_two.carbon

@@ -19,17 +19,21 @@ fn Main() {
 // CHECK:STDOUT: ; ModuleID = 'params_two.carbon'
 // CHECK:STDOUT: source_filename = "params_two.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFoo.Main(i32 %a, i32 %b) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFoo.Main(i32 %a, i32 %b) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CFoo.Main(i32 1, i32 2), !dbg !9
 // CHECK:STDOUT:   ret void, !dbg !10
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/call/params_two_comma.carbon

@@ -20,18 +20,22 @@ fn Main() {
 // CHECK:STDOUT: ; ModuleID = 'params_two_comma.carbon'
 // CHECK:STDOUT: source_filename = "params_two_comma.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFoo.Main(i32 %a, i32 %b) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFoo.Main(i32 %a, i32 %b) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CFoo.Main(i32 1, i32 2), !dbg !9
 // CHECK:STDOUT:   call void @_CFoo.Main(i32 1, i32 2), !dbg !10
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/call/params_zero.carbon

@@ -19,17 +19,21 @@ fn Main() {
 // CHECK:STDOUT: ; ModuleID = 'params_zero.carbon'
 // CHECK:STDOUT: source_filename = "params_zero.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFoo.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFoo.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CFoo.Main(), !dbg !9
 // CHECK:STDOUT:   ret void, !dbg !10
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/call/ref_param.carbon

@@ -20,12 +20,14 @@ fn Main() {
 // CHECK:STDOUT: ; ModuleID = 'ref_param.carbon'
 // CHECK:STDOUT: source_filename = "ref_param.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CDoNothing.Main(ptr %a) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CDoNothing.Main(ptr %a) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %a.var = alloca i32, align 4, !dbg !9
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %a.var), !dbg !9
@@ -35,9 +37,10 @@ fn Main() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/call/return_implicit.carbon

@@ -21,12 +21,14 @@ fn Main() {
 // CHECK:STDOUT: ; ModuleID = 'return_implicit.carbon'
 // CHECK:STDOUT: source_filename = "return_implicit.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMakeImplicitEmptyTuple.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMakeImplicitEmptyTuple.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %b.var = alloca {}, align 8, !dbg !9
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %b.var), !dbg !9
@@ -35,9 +37,10 @@ fn Main() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/call/struct_param.carbon

@@ -21,17 +21,21 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @struct.9ae.loc16_34.6 = internal constant { i32, i32 } { i32 2, i32 3 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main({ i32 } %b, ptr %c) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main({ i32 } %b, ptr %c) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CF.Main({ i32 } { i32 1 }, ptr @struct.9ae.loc16_34.6), !dbg !9
 // CHECK:STDOUT:   ret void, !dbg !10
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/call/tuple_param.carbon

@@ -21,17 +21,21 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @tuple.11a.loc16_20.6 = internal constant { i32, i32 } { i32 2, i32 3 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main({ i32 } %b, ptr %c) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main({ i32 } %b, ptr %c) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CF.Main({ i32 } { i32 1 }, ptr @tuple.11a.loc16_20.6), !dbg !9
 // CHECK:STDOUT:   ret void, !dbg !10
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/call/tuple_param_with_return_slot.carbon

@@ -23,7 +23,8 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @tuple.11a.loc18_20.6 = internal constant { i32, i32 } { i32 2, i32 3 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main(ptr sret({ i32, i32, i32 }) %return, { i32 } %b, ptr %c) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main(ptr sret({ i32, i32, i32 }) %return, { i32 } %b, ptr %c) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %tuple.elem0.loc14_12.tuple.elem = extractvalue { i32 } %b, 0, !dbg !7
 // CHECK:STDOUT:   %tuple.elem0.loc14_17.tuple.elem = getelementptr inbounds nuw { i32, i32 }, ptr %c, i32 0, i32 0, !dbg !8
@@ -39,7 +40,8 @@ fn Main() {
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc18_21.1.temp = alloca { i32, i32, i32 }, align 8, !dbg !13
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc18_21.1.temp), !dbg !13
@@ -48,9 +50,10 @@ fn Main() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/call/var_param.carbon

@@ -20,12 +20,14 @@ fn Main() {
 // CHECK:STDOUT: ; ModuleID = 'var_param.carbon'
 // CHECK:STDOUT: source_filename = "var_param.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CDoNothing.Main(i32 %a) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CDoNothing.Main(i32 %a) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CMain.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CMain.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %a.var = alloca i32, align 4, !dbg !9
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %a.var), !dbg !9
@@ -36,9 +38,10 @@ fn Main() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/declaration/simple.carbon

@@ -23,7 +23,8 @@ fn I() -> A;
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CF.Main(i32)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CG.Main(i32 %n) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CG.Main(i32 %n) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CF.Main(i32 %n), !dbg !7
 // CHECK:STDOUT:   ret void, !dbg !8
@@ -33,6 +34,8 @@ fn I() -> A;
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CI.Main()
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/definition/destroy.carbon

@@ -77,14 +77,16 @@ fn InitLet() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @C.val.loc12_6.3 = internal constant {} zeroinitializer
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main(ptr %x) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main(ptr %x) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CG.Main()
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CCallF.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CCallF.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc12_6.2.temp = alloca {}, align 8, !dbg !9
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc12_6.2.temp), !dbg !9
@@ -95,13 +97,14 @@ fn InitLet() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
@@ -124,14 +127,16 @@ fn InitLet() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @C.val.loc6_6.2 = internal constant {} zeroinitializer
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main(ptr %x) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main(ptr %x) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CG.Main()
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CCallF.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CCallF.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc6_6.1.temp = alloca {}, align 8, !dbg !9
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc6_6.1.temp), !dbg !9
@@ -142,13 +147,14 @@ fn InitLet() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
@@ -171,7 +177,8 @@ fn InitLet() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @C.val.loc7_12 = internal constant {} zeroinitializer
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CF.Main(ptr sret({}) %return) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CF.Main(ptr sret({}) %return) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @llvm.memcpy.p0.p0.i64(ptr align 1 %return, ptr align 1 @C.val.loc7_12, i64 0, i1 false), !dbg !7
 // CHECK:STDOUT:   ret void, !dbg !7
@@ -179,13 +186,15 @@ fn InitLet() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare void @_CG.Main()
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CForward.Main(ptr sret({}) %return) !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CForward.Main(ptr sret({}) %return) #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CF.Main(ptr %return), !dbg !9
 // CHECK:STDOUT:   ret void, !dbg !10
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CInitVar.Main() !dbg !11 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CInitVar.Main() #0 !dbg !11 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %local.var = alloca {}, align 8, !dbg !12
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %local.var), !dbg !12
@@ -194,7 +203,8 @@ fn InitLet() {
 // CHECK:STDOUT:   ret void, !dbg !15
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CInitLet.Main() !dbg !16 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CInitLet.Main() #0 !dbg !16 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc22_20.1.temp = alloca {}, align 8, !dbg !17
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc22_20.1.temp), !dbg !17
@@ -204,16 +214,17 @@ fn InitLet() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #0
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #2
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/definition/empty_struct.carbon

@@ -16,11 +16,14 @@ fn Echo(a: {}) {
 // CHECK:STDOUT: ; ModuleID = 'empty_struct.carbon'
 // CHECK:STDOUT: source_filename = "empty_struct.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CEcho.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CEcho.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/definition/params_one.carbon

@@ -15,11 +15,14 @@ fn Foo(a: i32) {}
 // CHECK:STDOUT: ; ModuleID = 'params_one.carbon'
 // CHECK:STDOUT: source_filename = "params_one.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFoo.Main(i32 %a) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFoo.Main(i32 %a) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/definition/params_two.carbon

@@ -15,11 +15,14 @@ fn Foo(a: i32, b: i32) {}
 // CHECK:STDOUT: ; ModuleID = 'params_two.carbon'
 // CHECK:STDOUT: source_filename = "params_two.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFoo.Main(i32 %a, i32 %b) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFoo.Main(i32 %a, i32 %b) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/definition/params_zero.carbon

@@ -15,11 +15,14 @@ fn Foo() {}
 // CHECK:STDOUT: ; ModuleID = 'params_zero.carbon'
 // CHECK:STDOUT: source_filename = "params_zero.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CFoo.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CFoo.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/definition/raw_name.carbon

@@ -16,11 +16,14 @@ fn r#self() {}
 // CHECK:STDOUT: ; ModuleID = 'raw_name.carbon'
 // CHECK:STDOUT: source_filename = "raw_name.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_Cself.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_Cself.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/definition/var_param.carbon

@@ -33,32 +33,38 @@ fn Call() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @X.val.loc16_13.2 = internal constant {} zeroinitializer
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_COneVar_i32.Main(ptr %n) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_COneVar_i32.Main(ptr %n) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_COneVar_X.Main(ptr %x) !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_COneVar_X.Main(ptr %x) #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !9
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CTwoVars.Main(ptr %a, ptr %b) !dbg !10 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CTwoVars.Main(ptr %a, ptr %b) #0 !dbg !10 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CVarThenLet.Main(ptr %a, ptr %b) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CVarThenLet.Main(ptr %a, ptr %b) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !13
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CLetThenVar.Main(i32 %a, ptr %b) !dbg !14 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CLetThenVar.Main(i32 %a, ptr %b) #0 !dbg !14 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !15
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CCall.Main() !dbg !16 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CCall.Main() #0 !dbg !16 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc15_15.1.temp = alloca i32, align 4, !dbg !17
 // CHECK:STDOUT:   %.loc16_13.1.temp = alloca {}, align 8, !dbg !18
@@ -90,17 +96,18 @@ fn Call() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 6, 5, 4, 3, 2, 1, 0 }
 // CHECK:STDOUT: uselistorder ptr @llvm.memcpy.p0.p0.i64, { 3, 2, 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/generic/call.carbon

@@ -37,7 +37,8 @@ fn G() {
 // CHECK:STDOUT: @C.val.loc20_3 = internal constant {} zeroinitializer
 // CHECK:STDOUT: @D.val.loc21_3 = internal constant {} zeroinitializer
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CG.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CG.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %c.var = alloca {}, align 8, !dbg !7
 // CHECK:STDOUT:   %d.var = alloca {}, align 8, !dbg !8
@@ -62,27 +63,31 @@ fn G() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Main.15b1f98bd9cc0c5b(ptr %x) !dbg !19 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Main.15b1f98bd9cc0c5b(ptr %x) #0 !dbg !19 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !20
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Main.b88d1103f417c6d4(i32 %x) !dbg !21 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Main.b88d1103f417c6d4(i32 %x) #0 !dbg !21 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !22
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Main.d4b5665541d5d7a8(double %x) !dbg !23 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Main.d4b5665541d5d7a8(double %x) #0 !dbg !23 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !24
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Main.5754c7a55c7cbe4a(%type %x) !dbg !25 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Main.5754c7a55c7cbe4a(%type %x) #0 !dbg !25 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !26
 // CHECK:STDOUT: }
@@ -92,8 +97,9 @@ fn G() {
 // CHECK:STDOUT: uselistorder ptr @llvm.memcpy.p0.p0.i64, { 1, 0 }
 // CHECK:STDOUT: uselistorder ptr @_CF.Main.15b1f98bd9cc0c5b, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/generic/call_basic.carbon

@@ -64,13 +64,15 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @C.val.loc15_44 = internal constant {} zeroinitializer
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @"_COp.C.Main:Copy.Core"(ptr sret({}) %return, ptr %self) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @"_COp.C.Main:Copy.Core"(ptr sret({}) %return, ptr %self) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @llvm.memcpy.p0.p0.i64(ptr align 1 %return, ptr align 1 @C.val.loc15_44, i64 0, i1 false), !dbg !7
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CM.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CM.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %n.var = alloca i32, align 4, !dbg !9
 // CHECK:STDOUT:   %m.var = alloca i32, align 4, !dbg !10
@@ -96,17 +98,19 @@ fn M() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #0
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #2
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Main.b88d1103f417c6d4(i32 %x) !dbg !24 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Main.b88d1103f417c6d4(i32 %x) #0 !dbg !24 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !25
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CG.Main.d756e33fa3337243(i32 %x) !dbg !26 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CG.Main.d756e33fa3337243(i32 %x) #0 !dbg !26 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc29_6.3.temp = alloca i32, align 4, !dbg !27
 // CHECK:STDOUT:   %.loc31_8.3.temp = alloca i32, align 4, !dbg !28
@@ -146,12 +150,14 @@ fn M() {
 // CHECK:STDOUT:   ret i32 %x, !dbg !45
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Main.d4b5665541d5d7a8(double %x) !dbg !46 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Main.d4b5665541d5d7a8(double %x) #0 !dbg !46 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !47
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr double @_CG.Main.6765264419ed942e(double %x) !dbg !48 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr double @_CG.Main.6765264419ed942e(double %x) #0 !dbg !48 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc29_6.3.temp = alloca double, align 8, !dbg !49
 // CHECK:STDOUT:   %.loc31_8.3.temp = alloca double, align 8, !dbg !50
@@ -191,27 +197,32 @@ fn M() {
 // CHECK:STDOUT:   ret double %x, !dbg !67
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CH.Main.5450dc8e8b8e0899(i32 %x) !dbg !68 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CH.Main.5450dc8e8b8e0899(i32 %x) #0 !dbg !68 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret i32 %x, !dbg !69
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr %type @_CH.Main.402deed6b8733082(%type %x) !dbg !70 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr %type @_CH.Main.402deed6b8733082(%type %x) #0 !dbg !70 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret %type %x, !dbg !71
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr double @_CH.Main.83aece103b0a8681(double %x) !dbg !72 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr double @_CH.Main.83aece103b0a8681(double %x) #0 !dbg !72 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret double %x, !dbg !73
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr ptr @_CH.Main.0a952f8bcc623ce6(ptr %x) !dbg !74 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr ptr @_CH.Main.0a952f8bcc623ce6(ptr %x) #0 !dbg !74 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret ptr %x, !dbg !75
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CH.Main.936d996ea935415c(ptr sret({}) %return, ptr %x) !dbg !76 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CH.Main.936d996ea935415c(ptr sret({}) %return, ptr %x) #0 !dbg !76 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @"_COp.C.Main:Copy.Core"(ptr %return, ptr %x), !dbg !77
 // CHECK:STDOUT:   ret void, !dbg !78
@@ -225,8 +236,9 @@ fn M() {
 // CHECK:STDOUT: uselistorder ptr @_CH.Main.0a952f8bcc623ce6, { 5, 2, 0, 4, 3, 1 }
 // CHECK:STDOUT: uselistorder ptr @_CH.Main.936d996ea935415c, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/generic/call_basic_depth.carbon

@@ -38,7 +38,8 @@ fn M() {
 // CHECK:STDOUT: ; ModuleID = 'call_basic_depth.carbon'
 // CHECK:STDOUT: source_filename = "call_basic_depth.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CM.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CM.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %n.var = alloca i32, align 4, !dbg !7
 // CHECK:STDOUT:   %m.var = alloca i32, align 4, !dbg !8
@@ -54,14 +55,16 @@ fn M() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Main.b88d1103f417c6d4(i32 %x) !dbg !15 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Main.b88d1103f417c6d4(i32 %x) #0 !dbg !15 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret void, !dbg !16
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CG.Main.d756e33fa3337243(i32 %x) !dbg !17 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CG.Main.d756e33fa3337243(i32 %x) #0 !dbg !17 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc25_6.3.temp = alloca i32, align 4, !dbg !18
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc25_6.3.temp), !dbg !18
@@ -71,7 +74,8 @@ fn M() {
 // CHECK:STDOUT:   ret i32 %x, !dbg !20
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CH.Main.5450dc8e8b8e0899(i32 %x) !dbg !21 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CH.Main.5450dc8e8b8e0899(i32 %x) #0 !dbg !21 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CF.Main.b88d1103f417c6d4(i32 %x), !dbg !22
 // CHECK:STDOUT:   ret i32 %x, !dbg !23
@@ -80,7 +84,8 @@ fn M() {
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 0, 2, 1 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/generic/call_dedup_ptr.carbon

@@ -26,7 +26,8 @@ fn M() {
 // CHECK:STDOUT: ; ModuleID = 'call_dedup_ptr.carbon'
 // CHECK:STDOUT: source_filename = "call_dedup_ptr.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CM.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CM.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %ptr_i32.var = alloca ptr, align 8, !dbg !7
 // CHECK:STDOUT:   %ptr_f64.var = alloca ptr, align 8, !dbg !8
@@ -44,9 +45,10 @@ fn M() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr ptr @_CF.Main.0a952f8bcc623ce6(ptr %x) !dbg !17 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr ptr @_CF.Main.0a952f8bcc623ce6(ptr %x) #0 !dbg !17 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret ptr %x, !dbg !18
 // CHECK:STDOUT: }
@@ -55,7 +57,8 @@ fn M() {
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 2, 1, 0 }
 // CHECK:STDOUT: uselistorder ptr @_CF.Main.0a952f8bcc623ce6, { 2, 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/generic/call_deref_ptr.carbon

@@ -45,7 +45,8 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: %type = type {}
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CM.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CM.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %ptr_i32.var = alloca ptr, align 8, !dbg !7
 // CHECK:STDOUT:   %ptr_f64.var = alloca ptr, align 8, !dbg !8
@@ -59,28 +60,32 @@ fn M() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Main.d756e33fa3337243(ptr %x) !dbg !14 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Main.d756e33fa3337243(ptr %x) #0 !dbg !14 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %A.call = call %type @_CA.Main.402deed6b8733082(%type zeroinitializer), !dbg !15
 // CHECK:STDOUT:   call void @_CB.Main.d756e33fa3337243(ptr %x), !dbg !16
 // CHECK:STDOUT:   ret void, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Main.6765264419ed942e(ptr %x) !dbg !18 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Main.6765264419ed942e(ptr %x) #0 !dbg !18 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %A.call = call %type @_CA.Main.402deed6b8733082(%type zeroinitializer), !dbg !19
 // CHECK:STDOUT:   call void @_CB.Main.6765264419ed942e(ptr %x), !dbg !20
 // CHECK:STDOUT:   ret void, !dbg !21
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr %type @_CA.Main.402deed6b8733082(%type %x) !dbg !22 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr %type @_CA.Main.402deed6b8733082(%type %x) #0 !dbg !22 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret %type %x, !dbg !23
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CB.Main.d756e33fa3337243(ptr %x) !dbg !24 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CB.Main.d756e33fa3337243(ptr %x) #0 !dbg !24 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc27_7.3.temp = alloca i32, align 4, !dbg !25
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc27_7.3.temp), !dbg !25
@@ -90,7 +95,8 @@ fn M() {
 // CHECK:STDOUT:   ret void, !dbg !27
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CB.Main.6765264419ed942e(ptr %x) !dbg !28 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CB.Main.6765264419ed942e(ptr %x) #0 !dbg !28 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc27_7.3.temp = alloca double, align 8, !dbg !29
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc27_7.3.temp), !dbg !29
@@ -100,12 +106,14 @@ fn M() {
 // CHECK:STDOUT:   ret void, !dbg !31
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CD.Main.5450dc8e8b8e0899(i32 %x) !dbg !32 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CD.Main.5450dc8e8b8e0899(i32 %x) #0 !dbg !32 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret i32 %x, !dbg !33
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr double @_CD.Main.83aece103b0a8681(double %x) !dbg !34 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr double @_CD.Main.83aece103b0a8681(double %x) #0 !dbg !34 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret double %x, !dbg !35
 // CHECK:STDOUT: }
@@ -114,7 +122,8 @@ fn M() {
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 0, 1, 3, 2 }
 // CHECK:STDOUT: uselistorder ptr @_CA.Main.402deed6b8733082, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/generic/call_different_associated_const.carbon

@@ -40,14 +40,16 @@ fn H() {
 // CHECK:STDOUT: ; ModuleID = 'call_different_associated_const.carbon'
 // CHECK:STDOUT: source_filename = "call_different_associated_const.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CH.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CH.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CG.Main.8e09687ead920c1c(), !dbg !7
 // CHECK:STDOUT:   call void @_CG.Main.8e09687ead920c1c(), !dbg !8
 // CHECK:STDOUT:   ret void, !dbg !9
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CG.Main.8e09687ead920c1c() !dbg !10 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CG.Main.8e09687ead920c1c() #0 !dbg !10 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %x.var = alloca ptr, align 8, !dbg !11
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %x.var), !dbg !11
@@ -55,12 +57,13 @@ fn H() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @_CG.Main.8e09687ead920c1c, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/generic/call_different_impls.carbon

@@ -38,19 +38,22 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @printf.int.format = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @"_CF.X.Main:I.Main"() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @"_CF.X.Main:I.Main"() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 1), !dbg !7
 // CHECK:STDOUT:   ret void, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @"_CF.Y.Main:I.Main"() !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @"_CF.Y.Main:I.Main"() #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 2), !dbg !10
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @main() !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @main() #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CG.Main.4d3c36eeac175c1f(), !dbg !13
 // CHECK:STDOUT:   call void @_CG.Main.7abe23e63361d139(), !dbg !14
@@ -59,13 +62,15 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare i32 @printf(ptr, ...)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CG.Main.4d3c36eeac175c1f() !dbg !16 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CG.Main.4d3c36eeac175c1f() #0 !dbg !16 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @"_CF.X.Main:I.Main"(), !dbg !17
 // CHECK:STDOUT:   ret void, !dbg !18
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CG.Main.7abe23e63361d139() !dbg !19 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CG.Main.7abe23e63361d139() #0 !dbg !19 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @"_CF.Y.Main:I.Main"(), !dbg !20
 // CHECK:STDOUT:   ret void, !dbg !21
@@ -74,6 +79,8 @@ fn Run() {
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @printf, { 1, 0 }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/generic/call_different_impls_with_const.carbon

@@ -47,19 +47,22 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @printf.int.format = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i1 @"_CF.X.Main:I.Main"() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i1 @"_CF.X.Main:I.Main"() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 1), !dbg !7
 // CHECK:STDOUT:   ret i1 false, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @"_CF.Y.Main:I.Main"() !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @"_CF.Y.Main:I.Main"() #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 2), !dbg !10
 // CHECK:STDOUT:   ret i32 2, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @main() !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @main() #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CG.Main.903f115cc96ac8da(), !dbg !13
 // CHECK:STDOUT:   call void @_CG.Main.34c09acedc4a7473(), !dbg !14
@@ -68,7 +71,8 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare i32 @printf(ptr, ...)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CG.Main.903f115cc96ac8da() !dbg !16 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CG.Main.903f115cc96ac8da() #0 !dbg !16 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc37_20.1.temp = alloca i1, align 1, !dbg !17
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc37_20.1.temp), !dbg !17
@@ -80,7 +84,8 @@ fn Run() {
 // CHECK:STDOUT:   ret void, !dbg !18
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CG.Main.34c09acedc4a7473() !dbg !19 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CG.Main.34c09acedc4a7473() #0 !dbg !19 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc37_20.1.temp = alloca i32, align 4, !dbg !20
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc37_20.1.temp), !dbg !20
@@ -91,13 +96,14 @@ fn Run() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @printf, { 1, 0 }
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/generic/call_different_specific.carbon

@@ -52,7 +52,8 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: %type = type {}
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CM.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CM.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %ptr_i32.var = alloca ptr, align 8, !dbg !7
 // CHECK:STDOUT:   %ptr_f64.var = alloca ptr, align 8, !dbg !8
@@ -66,28 +67,32 @@ fn M() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Main.d756e33fa3337243(ptr %x) !dbg !14 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Main.d756e33fa3337243(ptr %x) #0 !dbg !14 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %A.call = call %type @_CA.Main.402deed6b8733082(%type zeroinitializer), !dbg !15
 // CHECK:STDOUT:   call void @_CB.Main.d756e33fa3337243(ptr %x), !dbg !16
 // CHECK:STDOUT:   ret void, !dbg !17
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Main.6765264419ed942e(ptr %x) !dbg !18 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Main.6765264419ed942e(ptr %x) #0 !dbg !18 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %A.call = call %type @_CA.Main.402deed6b8733082(%type zeroinitializer), !dbg !19
 // CHECK:STDOUT:   call void @_CB.Main.6765264419ed942e(ptr %x), !dbg !20
 // CHECK:STDOUT:   ret void, !dbg !21
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr %type @_CA.Main.402deed6b8733082(%type %x) !dbg !22 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr %type @_CA.Main.402deed6b8733082(%type %x) #0 !dbg !22 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret %type %x, !dbg !23
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CB.Main.d756e33fa3337243(ptr %x) !dbg !24 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CB.Main.d756e33fa3337243(ptr %x) #0 !dbg !24 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc34_7.3.temp = alloca i32, align 4, !dbg !25
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc34_7.3.temp), !dbg !25
@@ -97,7 +102,8 @@ fn M() {
 // CHECK:STDOUT:   ret void, !dbg !27
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CB.Main.6765264419ed942e(ptr %x) !dbg !28 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CB.Main.6765264419ed942e(ptr %x) #0 !dbg !28 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc34_7.3.temp = alloca double, align 8, !dbg !29
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc34_7.3.temp), !dbg !29
@@ -107,12 +113,14 @@ fn M() {
 // CHECK:STDOUT:   ret void, !dbg !31
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CD.Main.5450dc8e8b8e0899(i32 %x) !dbg !32 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CD.Main.5450dc8e8b8e0899(i32 %x) #0 !dbg !32 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret i32 %x, !dbg !33
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr double @_CD.Main.83aece103b0a8681(double %x) !dbg !34 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr double @_CD.Main.83aece103b0a8681(double %x) #0 !dbg !34 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret double %x, !dbg !35
 // CHECK:STDOUT: }
@@ -121,7 +129,8 @@ fn M() {
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 0, 1, 3, 2 }
 // CHECK:STDOUT: uselistorder ptr @_CA.Main.402deed6b8733082, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/generic/call_impl_function.carbon

@@ -46,24 +46,29 @@ fn G() {
 // CHECK:STDOUT: ; ModuleID = 'call_impl_function.carbon'
 // CHECK:STDOUT: source_filename = "call_impl_function.carbon"
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @"_CF.ImplsSomeInterface.Main:SomeInterface.Main"(i32 %x) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @"_CF.ImplsSomeInterface.Main:SomeInterface.Main"(i32 %x) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.Negate.impl.Op.call = sub i32 0, %x, !dbg !7
 // CHECK:STDOUT:   ret i32 %Int.as.Negate.impl.Op.call, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CG.Main() !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CG.Main() #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %CallGenericMethod.call = call i32 @_CCallGenericMethod.Main.dc54e41cb8a9bf68(i32 10), !dbg !10
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CCallGenericMethod.Main.dc54e41cb8a9bf68(i32 %x) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CCallGenericMethod.Main.dc54e41cb8a9bf68(i32 %x) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %.loc36_15 = call i32 @"_CF.ImplsSomeInterface.Main:SomeInterface.Main"(i32 %x), !dbg !13
 // CHECK:STDOUT:   ret i32 %.loc36_15, !dbg !14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT:

toolchain/lower/testdata/function/generic/call_method.carbon

@@ -27,7 +27,8 @@ fn CallF() -> i32 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @C.val.loc20_3 = internal constant {} zeroinitializer
 // CHECK:STDOUT:
-// CHECK:STDOUT: define i32 @_CCallF.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CCallF.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %c.var = alloca {}, align 8, !dbg !7
 // CHECK:STDOUT:   %n.var = alloca i32, align 4, !dbg !8
@@ -41,12 +42,13 @@ fn CallF() -> i32 {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #2
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CF.C.Main.5450dc8e8b8e0899(ptr %self, i32 %x) !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CF.C.Main.5450dc8e8b8e0899(ptr %self, i32 %x) #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   ret i32 %x, !dbg !13
 // CHECK:STDOUT: }
@@ -54,8 +56,9 @@ fn CallF() -> i32 {
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/generic/call_recursive_basic.carbon

@@ -45,13 +45,15 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @C.val.loc15_44 = internal constant {} zeroinitializer
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @"_COp.C.Main:Copy.Core"(ptr sret({}) %return, ptr %self) !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @"_COp.C.Main:Copy.Core"(ptr sret({}) %return, ptr %self) #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @llvm.memcpy.p0.p0.i64(ptr align 1 %return, ptr align 1 @C.val.loc15_44, i64 0, i1 false), !dbg !7
 // CHECK:STDOUT:   ret void, !dbg !7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CM.Main() !dbg !8 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CM.Main() #0 !dbg !8 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %n.var = alloca i32, align 4, !dbg !9
 // CHECK:STDOUT:   %m.var = alloca double, align 8, !dbg !10
@@ -80,12 +82,13 @@ fn M() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #0
+// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #2
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CF.Main.5450dc8e8b8e0899(i32 %x, i32 %count) !dbg !24 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CF.Main.5450dc8e8b8e0899(i32 %x, i32 %count) #0 !dbg !24 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 0, !dbg !25
 // CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then, label %if.else, !dbg !26
@@ -99,7 +102,8 @@ fn M() {
 // CHECK:STDOUT:   ret i32 %F.call, !dbg !30
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr double @_CF.Main.83aece103b0a8681(double %x, i32 %count) !dbg !31 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr double @_CF.Main.83aece103b0a8681(double %x, i32 %count) #0 !dbg !31 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 0, !dbg !32
 // CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then, label %if.else, !dbg !33
@@ -113,7 +117,8 @@ fn M() {
 // CHECK:STDOUT:   ret double %F.call, !dbg !37
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr ptr @_CF.Main.0a952f8bcc623ce6(ptr %x, i32 %count) !dbg !38 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr ptr @_CF.Main.0a952f8bcc623ce6(ptr %x, i32 %count) #0 !dbg !38 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 0, !dbg !39
 // CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then, label %if.else, !dbg !40
@@ -127,7 +132,8 @@ fn M() {
 // CHECK:STDOUT:   ret ptr %F.call, !dbg !44
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr void @_CF.Main.936d996ea935415c(ptr sret({}) %return, ptr %x, i32 %count) !dbg !45 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CF.Main.936d996ea935415c(ptr sret({}) %return, ptr %x, i32 %count) #0 !dbg !45 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 0, !dbg !46
 // CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then, label %if.else, !dbg !47
@@ -146,8 +152,9 @@ fn M() {
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 5, 4, 3, 2, 1, 0 }
 // CHECK:STDOUT: uselistorder ptr @_CF.Main.0a952f8bcc623ce6, { 1, 2, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
-// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/generic/call_recursive_diamond.carbon

@@ -61,7 +61,8 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @printf.int.format = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @_CM.Main() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CM.Main() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %n.var = alloca i32, align 4, !dbg !7
 // CHECK:STDOUT:   %m.var = alloca double, align 8, !dbg !8
@@ -85,9 +86,10 @@ fn M() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
-// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #0
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CA.Main.5450dc8e8b8e0899(i32 %x, i32 %count) !dbg !20 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CA.Main.5450dc8e8b8e0899(i32 %x, i32 %count) #0 !dbg !20 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 4, !dbg !21
 // CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc22, label %if.else.loc22, !dbg !22
@@ -109,7 +111,8 @@ fn M() {
 // CHECK:STDOUT:   ret i32 %C.call, !dbg !29
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr double @_CA.Main.83aece103b0a8681(double %x, i32 %count) !dbg !30 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr double @_CA.Main.83aece103b0a8681(double %x, i32 %count) #0 !dbg !30 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 4, !dbg !31
 // CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc22, label %if.else.loc22, !dbg !32
@@ -131,7 +134,8 @@ fn M() {
 // CHECK:STDOUT:   ret double %C.call, !dbg !39
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr ptr @_CA.Main.0a952f8bcc623ce6(ptr %x, i32 %count) !dbg !40 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr ptr @_CA.Main.0a952f8bcc623ce6(ptr %x, i32 %count) #0 !dbg !40 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 4, !dbg !41
 // CHECK:STDOUT:   br i1 %Int.as.OrderedWith.impl.Greater.call, label %if.then.loc22, label %if.else.loc22, !dbg !42
@@ -153,42 +157,48 @@ fn M() {
 // CHECK:STDOUT:   ret ptr %C.call, !dbg !49
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CB.Main.5450dc8e8b8e0899(i32 %x, i32 %count) !dbg !50 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CB.Main.5450dc8e8b8e0899(i32 %x, i32 %count) #0 !dbg !50 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 1), !dbg !51
 // CHECK:STDOUT:   %D.call = call i32 @_CD.Main.5450dc8e8b8e0899(i32 %x, i32 %count), !dbg !52
 // CHECK:STDOUT:   ret i32 %D.call, !dbg !53
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CC.Main.5450dc8e8b8e0899(i32 %x, i32 %count) !dbg !54 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CC.Main.5450dc8e8b8e0899(i32 %x, i32 %count) #0 !dbg !54 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 2), !dbg !55
 // CHECK:STDOUT:   %D.call = call i32 @_CD.Main.5450dc8e8b8e0899(i32 %x, i32 %count), !dbg !56
 // CHECK:STDOUT:   ret i32 %D.call, !dbg !57
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr double @_CB.Main.83aece103b0a8681(double %x, i32 %count) !dbg !58 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr double @_CB.Main.83aece103b0a8681(double %x, i32 %count) #0 !dbg !58 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 1), !dbg !59
 // CHECK:STDOUT:   %D.call = call double @_CD.Main.83aece103b0a8681(double %x, i32 %count), !dbg !60
 // CHECK:STDOUT:   ret double %D.call, !dbg !61
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr double @_CC.Main.83aece103b0a8681(double %x, i32 %count) !dbg !62 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr double @_CC.Main.83aece103b0a8681(double %x, i32 %count) #0 !dbg !62 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 2), !dbg !63
 // CHECK:STDOUT:   %D.call = call double @_CD.Main.83aece103b0a8681(double %x, i32 %count), !dbg !64
 // CHECK:STDOUT:   ret double %D.call, !dbg !65
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr ptr @_CB.Main.0a952f8bcc623ce6(ptr %x, i32 %count) !dbg !66 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr ptr @_CB.Main.0a952f8bcc623ce6(ptr %x, i32 %count) #0 !dbg !66 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 1), !dbg !67
 // CHECK:STDOUT:   %D.call = call ptr @_CD.Main.0a952f8bcc623ce6(ptr %x, i32 %count), !dbg !68
 // CHECK:STDOUT:   ret ptr %D.call, !dbg !69
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr ptr @_CC.Main.0a952f8bcc623ce6(ptr %x, i32 %count) !dbg !70 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr ptr @_CC.Main.0a952f8bcc623ce6(ptr %x, i32 %count) #0 !dbg !70 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 2), !dbg !71
 // CHECK:STDOUT:   %D.call = call ptr @_CD.Main.0a952f8bcc623ce6(ptr %x, i32 %count), !dbg !72
@@ -197,21 +207,24 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare i32 @printf(ptr, ...)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CD.Main.5450dc8e8b8e0899(i32 %x, i32 %count) !dbg !74 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CD.Main.5450dc8e8b8e0899(i32 %x, i32 %count) #0 !dbg !74 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.AddWith.impl.Op.call = add i32 %count, 1, !dbg !75
 // CHECK:STDOUT:   %A.call = call i32 @_CA.Main.5450dc8e8b8e0899(i32 %x, i32 %Int.as.AddWith.impl.Op.call), !dbg !76
 // CHECK:STDOUT:   ret i32 %A.call, !dbg !77
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr double @_CD.Main.83aece103b0a8681(double %x, i32 %count) !dbg !78 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr double @_CD.Main.83aece103b0a8681(double %x, i32 %count) #0 !dbg !78 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.AddWith.impl.Op.call = add i32 %count, 1, !dbg !79
 // CHECK:STDOUT:   %A.call = call double @_CA.Main.83aece103b0a8681(double %x, i32 %Int.as.AddWith.impl.Op.call), !dbg !80
 // CHECK:STDOUT:   ret double %A.call, !dbg !81
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr ptr @_CD.Main.0a952f8bcc623ce6(ptr %x, i32 %count) !dbg !82 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr ptr @_CD.Main.0a952f8bcc623ce6(ptr %x, i32 %count) #0 !dbg !82 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Int.as.AddWith.impl.Op.call = add i32 %count, 1, !dbg !83
 // CHECK:STDOUT:   %A.call = call ptr @_CA.Main.0a952f8bcc623ce6(ptr %x, i32 %Int.as.AddWith.impl.Op.call), !dbg !84
@@ -226,7 +239,8 @@ fn M() {
 // CHECK:STDOUT: uselistorder ptr @_CD.Main.83aece103b0a8681, { 1, 0 }
 // CHECK:STDOUT: uselistorder ptr @_CD.Main.0a952f8bcc623ce6, { 1, 0 }
 // CHECK:STDOUT:
-// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}

toolchain/lower/testdata/function/generic/call_recursive_impl.carbon

@@ -46,19 +46,22 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: @printf.int.format = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @"_CF.X.Main:I.Main"() !dbg !4 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @"_CF.X.Main:I.Main"() #0 !dbg !4 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 1), !dbg !7
 // CHECK:STDOUT:   ret void, !dbg !8
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @"_CF.Y.Main:I.Main"() !dbg !9 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @"_CF.Y.Main:I.Main"() #0 !dbg !9 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 2), !dbg !10
 // CHECK:STDOUT:   ret void, !dbg !11
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define void @main() !dbg !12 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @main() #0 !dbg !12 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   %G.call.loc40 = call i32 @_CG.Main.4d3c36eeac175c1f(i32 0), !dbg !13
 // CHECK:STDOUT:   %G.call.loc41 = call i32 @_CG.Main.7abe23e63361d139(i32 0), !dbg !14
@@ -67,7 +70,8 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: declare i32 @printf(ptr, ...)
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CG.Main.4d3c36eeac175c1f(i32 %count) !dbg !16 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CG.Main.4d3c36eeac175c1f(i32 %count) #0 !dbg !16 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @"_CF.X.Main:I.Main"(), !dbg !17
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 0, !dbg !18
@@ -82,7 +86,8 @@ fn Run() {
 // CHECK:STDOUT:   ret i32 %G.call, !dbg !23
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: define linkonce_odr i32 @_CG.Main.7abe23e63361d139(i32 %count) !dbg !24 {
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr i32 @_CG.Main.7abe23e63361d139(i32 %count) #0 !dbg !24 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @"_CF.Y.Main:I.Main"(), !dbg !25
 // CHECK:STDOUT:   %Int.as.OrderedWith.impl.Greater.call = icmp sgt i32 %count, 0, !dbg !26
@@ -100,6 +105,8 @@ fn Run() {
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @printf, { 1, 0 }
 // CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT:
 // CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
 // CHECK:STDOUT: !llvm.dbg.cu = !{!2}
 // CHECK:STDOUT: