Stop substituting into `MetaInstId` operands. (#5328)

A `MetaInstId` is intended to represent a handle to an instruction in a
generic as an operand to a template action; substituting into the action
should not substitute into the referenced instruction.

Fixing this exposed a bug in `GetOrAddInst` where it would return an
`InstId` of an unattached symbolic constant in some cases, rather than
the `InstId` of an instruction that has the relevant (attached) constant
value. That's fixed for now by turning off the `GetOrAddInst`
optimization in that case, but in future we can refine this by adding
the instruction to the eval block for the generic only, and not to the
body of the generic.

toolchain/check/inst.cpp

@@ -112,6 +112,12 @@ auto GetOrAddInst(Context& context, SemIR::LocIdAndInst loc_id_and_inst)
       return SemIR::InstId::None;
     }
 
+    if (const_id.is_symbolic()) {
+      // TODO: Only add this instruction to the eval block, and don't
+      // re-evaluate it.
+      return AddInst(context, loc_id_and_inst);
+    }
+
     CARBON_VLOG_TO(context.vlog_stream(), "GetOrAddInst: constant: {0}\n",
                    loc_id_and_inst.inst);
     return context.constant_values().GetInstId(const_id);

toolchain/check/subst.cpp

@@ -83,12 +83,6 @@ static auto PushOperand(Context& context, Worklist& worklist,
       }
       break;
     }
-    case CARBON_KIND(SemIR::MetaInstId inst_id): {
-      if (inst_id.has_value()) {
-        worklist.Push(inst_id);
-      }
-      break;
-    }
     case CARBON_KIND(SemIR::TypeInstId inst_id): {
       if (inst_id.has_value()) {
         worklist.Push(inst_id);
@@ -175,12 +169,6 @@ static auto PopOperand(Context& context, Worklist& worklist,
       }
       return worklist.Pop().index;
     }
-    case CARBON_KIND(SemIR::MetaInstId inst_id): {
-      if (!inst_id.has_value()) {
-        return arg.value();
-      }
-      return worklist.Pop().index;
-    }
     case CARBON_KIND(SemIR::TypeInstId inst_id): {
       if (!inst_id.has_value()) {
         return arg.value();

toolchain/check/testdata/class/generic/member_access.carbon

@@ -420,8 +420,15 @@ fn StaticMemberFunctionCall(T:! type) -> Class(T) {
 // CHECK:STDOUT:   %StaticMemberFunctionCall.type: type = fn_type @StaticMemberFunctionCall [concrete]
 // CHECK:STDOUT:   %StaticMemberFunctionCall: %StaticMemberFunctionCall.type = struct_value () [concrete]
 // CHECK:STDOUT:   %Make.specific_fn: <specific function> = specific_function %Make, @Make(%T) [symbolic]
+// CHECK:STDOUT:   %Dest: type = bind_symbolic_name Dest, 0 [symbolic]
+// CHECK:STDOUT:   %Convert.type.275: type = fn_type @Convert, @ImplicitAs(%Dest) [symbolic]
+// CHECK:STDOUT:   %Convert.42e: %Convert.type.275 = struct_value () [symbolic]
+// CHECK:STDOUT:   %ImplicitAs.assoc_type.ca0: type = assoc_entity_type @ImplicitAs, @ImplicitAs(%Dest) [symbolic]
 // CHECK:STDOUT:   %ImplicitAs.type.53b: type = facet_type <@ImplicitAs, @ImplicitAs(%Class)> [symbolic]
+// CHECK:STDOUT:   %ImplicitAs.assoc_type.6aa: type = assoc_entity_type @ImplicitAs, @ImplicitAs(%Class) [symbolic]
+// CHECK:STDOUT:   %assoc0.f00: %ImplicitAs.assoc_type.6aa = assoc_entity element0, imports.%Core.import_ref.1c7 [symbolic]
 // CHECK:STDOUT:   %require_complete.d81: <witness> = require_complete_type %ImplicitAs.type.53b [symbolic]
+// CHECK:STDOUT:   %assoc0.dc0: %ImplicitAs.assoc_type.ca0 = assoc_entity element0, imports.%Core.import_ref.207 [symbolic]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
@@ -430,6 +437,8 @@ fn StaticMemberFunctionCall(T:! type) -> Class(T) {
 // CHECK:STDOUT:     import Core//prelude
 // CHECK:STDOUT:     import Core//prelude/...
 // CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import_ref.492: @ImplicitAs.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.ca0) = import_ref Core//prelude/operators/as, loc13_35, loaded [symbolic = @ImplicitAs.%assoc0 (constants.%assoc0.dc0)]
+// CHECK:STDOUT:   %Core.import_ref.1c7: @ImplicitAs.%Convert.type (%Convert.type.275) = import_ref Core//prelude/operators/as, loc13_35, loaded [symbolic = @ImplicitAs.%Convert (constants.%Convert.42e)]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
@@ -516,8 +525,10 @@ fn StaticMemberFunctionCall(T:! type) -> Class(T) {
 // CHECK:STDOUT:   %Make.type: type = fn_type @Make, @Class(%T.loc8_29.2) [symbolic = %Make.type (constants.%Make.type)]
 // CHECK:STDOUT:   %Make: @StaticMemberFunctionCall.%Make.type (%Make.type) = struct_value () [symbolic = %Make (constants.%Make)]
 // CHECK:STDOUT:   %Make.specific_fn.loc16_18.2: <specific function> = specific_function %Make, @Make(%T.loc8_29.2) [symbolic = %Make.specific_fn.loc16_18.2 (constants.%Make.specific_fn)]
-// CHECK:STDOUT:   %ImplicitAs.type: type = facet_type <@ImplicitAs, @ImplicitAs(%Class.loc8_49.2)> [symbolic = %ImplicitAs.type (constants.%ImplicitAs.type.53b)]
-// CHECK:STDOUT:   %require_complete.loc16_25: <witness> = require_complete_type %ImplicitAs.type [symbolic = %require_complete.loc16_25 (constants.%require_complete.d81)]
+// CHECK:STDOUT:   %ImplicitAs.type.loc16_25.2: type = facet_type <@ImplicitAs, @ImplicitAs(%Class.loc8_49.2)> [symbolic = %ImplicitAs.type.loc16_25.2 (constants.%ImplicitAs.type.53b)]
+// CHECK:STDOUT:   %require_complete.loc16_25: <witness> = require_complete_type %ImplicitAs.type.loc16_25.2 [symbolic = %require_complete.loc16_25 (constants.%require_complete.d81)]
+// CHECK:STDOUT:   %ImplicitAs.assoc_type: type = assoc_entity_type @ImplicitAs, @ImplicitAs(%Class.loc8_49.2) [symbolic = %ImplicitAs.assoc_type (constants.%ImplicitAs.assoc_type.6aa)]
+// CHECK:STDOUT:   %assoc0: @StaticMemberFunctionCall.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.6aa) = assoc_entity element0, imports.%Core.import_ref.1c7 [symbolic = %assoc0 (constants.%assoc0.f00)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn(%T.patt.loc8_29.1: type) -> %return.param_patt: @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) {
 // CHECK:STDOUT:   !entry:
@@ -529,7 +540,10 @@ fn StaticMemberFunctionCall(T:! type) -> Class(T) {
 // CHECK:STDOUT:     %Make.specific_fn.loc16_18.1: <specific function> = specific_function %Make.ref, @Make(constants.%T) [symbolic = %Make.specific_fn.loc16_18.2 (constants.%Make.specific_fn)]
 // CHECK:STDOUT:     %.loc16_24: ref @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) = temporary_storage
 // CHECK:STDOUT:     %Make.call: init @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) = call %Make.specific_fn.loc16_18.1() to %.loc16_24
-// CHECK:STDOUT:     %.loc16_25: @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) = converted %Make.call, <error> [concrete = <error>]
+// CHECK:STDOUT:     %ImplicitAs.type.loc16_25.1: type = facet_type <@ImplicitAs, @ImplicitAs(constants.%Class)> [symbolic = %ImplicitAs.type.loc16_25.2 (constants.%ImplicitAs.type.53b)]
+// CHECK:STDOUT:     %.loc16_25.1: @StaticMemberFunctionCall.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.6aa) = specific_constant imports.%Core.import_ref.492, @ImplicitAs(constants.%Class) [symbolic = %assoc0 (constants.%assoc0.f00)]
+// CHECK:STDOUT:     %Convert.ref: @StaticMemberFunctionCall.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.6aa) = name_ref Convert, %.loc16_25.1 [symbolic = %assoc0 (constants.%assoc0.f00)]
+// CHECK:STDOUT:     %.loc16_25.2: @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) = converted %Make.call, <error> [concrete = <error>]
 // CHECK:STDOUT:     return <error> to %return
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }

toolchain/check/testdata/facet/min_prelude/convert_facet_value_to_narrowed_facet_type.carbon

@@ -917,8 +917,8 @@ fn CallsWithTypeExplicit(U:! type) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:   %require_complete: <witness> = require_complete_type %W.as_type.loc11_44.2 [symbolic = %require_complete (constants.%require_complete.ba9)]
-// CHECK:STDOUT:   %W.as_wit.iface0: <witness> = facet_access_witness %W.loc11_22.2, element0 [symbolic = %W.as_wit.iface0 (constants.%W.as_wit.iface0)]
-// CHECK:STDOUT:   %Animal.facet.loc12_14.3: %Animal.type = facet_value %W.as_type.loc11_44.2, (%W.as_wit.iface0) [symbolic = %Animal.facet.loc12_14.3 (constants.%Animal.facet)]
+// CHECK:STDOUT:   %W.as_wit.iface0.loc12_14.3: <witness> = facet_access_witness %W.loc11_22.2, element0 [symbolic = %W.as_wit.iface0.loc12_14.3 (constants.%W.as_wit.iface0)]
+// CHECK:STDOUT:   %Animal.facet.loc12_14.3: %Animal.type = facet_value %W.as_type.loc11_44.2, (%W.as_wit.iface0.loc12_14.3) [symbolic = %Animal.facet.loc12_14.3 (constants.%Animal.facet)]
 // CHECK:STDOUT:   %Eats.lookup_impl_witness: <witness> = lookup_impl_witness %W.loc11_22.2, @Eats [symbolic = %Eats.lookup_impl_witness (constants.%Eats.lookup_impl_witness)]
 // CHECK:STDOUT:   %W.as_wit.iface1.loc12_14.3: <witness> = facet_access_witness %W.loc11_22.2, element1 [symbolic = %W.as_wit.iface1.loc12_14.3 (constants.%W.as_wit.iface1)]
 // CHECK:STDOUT:   %facet_value.loc12_14.3: %facet_type.6ff = facet_value %W.as_type.loc11_44.2, (%Eats.lookup_impl_witness, %W.as_wit.iface1.loc12_14.3) [symbolic = %facet_value.loc12_14.3 (constants.%facet_value)]
@@ -930,14 +930,16 @@ fn CallsWithTypeExplicit(U:! type) {
 // CHECK:STDOUT:     %w.ref: @HandleTameAnimal2.%W.as_type.loc11_44.2 (%W.as_type) = name_ref w, %w
 // CHECK:STDOUT:     %W.as_type.loc12_14.1: type = facet_access_type constants.%W [symbolic = %W.as_type.loc11_44.2 (constants.%W.as_type)]
 // CHECK:STDOUT:     %.loc12_14.1: type = converted constants.%W, %W.as_type.loc12_14.1 [symbolic = %W.as_type.loc11_44.2 (constants.%W.as_type)]
-// CHECK:STDOUT:     %Animal.facet.loc12_14.1: %Animal.type = facet_value constants.%W.as_type, (constants.%W.as_wit.iface0) [symbolic = %Animal.facet.loc12_14.3 (constants.%Animal.facet)]
+// CHECK:STDOUT:     %W.as_wit.iface0.loc12_14.1: <witness> = facet_access_witness constants.%W, element0 [symbolic = %W.as_wit.iface0.loc12_14.3 (constants.%W.as_wit.iface0)]
+// CHECK:STDOUT:     %Animal.facet.loc12_14.1: %Animal.type = facet_value constants.%W.as_type, (%W.as_wit.iface0.loc12_14.1) [symbolic = %Animal.facet.loc12_14.3 (constants.%Animal.facet)]
 // CHECK:STDOUT:     %.loc12_14.2: %Animal.type = converted %.loc12_14.1, %Animal.facet.loc12_14.1 [symbolic = %Animal.facet.loc12_14.3 (constants.%Animal.facet)]
 // CHECK:STDOUT:     %W.as_wit.iface1.loc12_14.1: <witness> = facet_access_witness constants.%W, element1 [symbolic = %W.as_wit.iface1.loc12_14.3 (constants.%W.as_wit.iface1)]
 // CHECK:STDOUT:     %facet_value.loc12_14.1: %facet_type.6ff = facet_value constants.%W.as_type, (constants.%Eats.lookup_impl_witness, %W.as_wit.iface1.loc12_14.1) [symbolic = %facet_value.loc12_14.3 (constants.%facet_value)]
 // CHECK:STDOUT:     %.loc12_14.3: %facet_type.6ff = converted constants.%W.as_type, %facet_value.loc12_14.1 [symbolic = %facet_value.loc12_14.3 (constants.%facet_value)]
 // CHECK:STDOUT:     %W.as_type.loc12_14.2: type = facet_access_type constants.%W [symbolic = %W.as_type.loc11_44.2 (constants.%W.as_type)]
 // CHECK:STDOUT:     %.loc12_14.4: type = converted constants.%W, %W.as_type.loc12_14.2 [symbolic = %W.as_type.loc11_44.2 (constants.%W.as_type)]
-// CHECK:STDOUT:     %Animal.facet.loc12_14.2: %Animal.type = facet_value constants.%W.as_type, (constants.%W.as_wit.iface0) [symbolic = %Animal.facet.loc12_14.3 (constants.%Animal.facet)]
+// CHECK:STDOUT:     %W.as_wit.iface0.loc12_14.2: <witness> = facet_access_witness constants.%W, element0 [symbolic = %W.as_wit.iface0.loc12_14.3 (constants.%W.as_wit.iface0)]
+// CHECK:STDOUT:     %Animal.facet.loc12_14.2: %Animal.type = facet_value constants.%W.as_type, (%W.as_wit.iface0.loc12_14.2) [symbolic = %Animal.facet.loc12_14.3 (constants.%Animal.facet)]
 // CHECK:STDOUT:     %.loc12_14.5: %Animal.type = converted %.loc12_14.4, %Animal.facet.loc12_14.2 [symbolic = %Animal.facet.loc12_14.3 (constants.%Animal.facet)]
 // CHECK:STDOUT:     %W.as_wit.iface1.loc12_14.2: <witness> = facet_access_witness constants.%W, element1 [symbolic = %W.as_wit.iface1.loc12_14.3 (constants.%W.as_wit.iface1)]
 // CHECK:STDOUT:     %facet_value.loc12_14.2: %facet_type.6ff = facet_value constants.%W.as_type, (constants.%Eats.lookup_impl_witness, %W.as_wit.iface1.loc12_14.2) [symbolic = %facet_value.loc12_14.3 (constants.%facet_value)]

toolchain/check/testdata/generic/template/unimplemented.carbon

@@ -268,8 +268,8 @@ fn F[template T:! type](x: T) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:   %require_complete: <witness> = require_complete_type %T.loc4_15.2 [template = %require_complete (constants.%require_complete.4ae)]
-// CHECK:STDOUT:   %ImplicitAs.type: type = facet_type <@ImplicitAs, @ImplicitAs(%T.loc4_15.2)> [template = %ImplicitAs.type (constants.%ImplicitAs.type.d628ce.2)]
-// CHECK:STDOUT:   %.loc14_3.4: <instruction> = access_member_action %ImplicitAs.type, Convert [template]
+// CHECK:STDOUT:   %ImplicitAs.type.loc14_3.2: type = facet_type <@ImplicitAs, @ImplicitAs(%T.loc4_15.2)> [template = %ImplicitAs.type.loc14_3.2 (constants.%ImplicitAs.type.d628ce.2)]
+// CHECK:STDOUT:   %.loc14_3.4: <instruction> = access_member_action %ImplicitAs.type.loc14_3.1, Convert [template]
 // CHECK:STDOUT:   %.loc14_3.5: type = type_of_inst %.loc14_3.4 [template]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn[%T.patt.loc4_15.1: type](%x.param_patt: @F.%T.loc4_15.2 (%T)) {
@@ -280,6 +280,7 @@ fn F[template T:! type](x: T) {
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %v.var: ref @F.%T.loc4_15.2 (%T) = var v
 // CHECK:STDOUT:     %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0]
+// CHECK:STDOUT:     %ImplicitAs.type.loc14_3.1: type = facet_type <@ImplicitAs, @ImplicitAs(constants.%T)> [template = %ImplicitAs.type.loc14_3.2 (constants.%ImplicitAs.type.d628ce.2)]
 // CHECK:STDOUT:     %.loc14_3.2: @F.%.loc14_3.5 (@F.%.loc14_3.5) = splice_inst %.loc14_3.4
 // CHECK:STDOUT:     %.loc14_3.3: @F.%T.loc4_15.2 (%T) = converted %int_0, <error> [concrete = <error>]
 // CHECK:STDOUT:     assign %v.var, <error>

toolchain/check/testdata/impl/lookup/min_prelude/specialization_with_symbolic_rewrite.carbon

@@ -762,8 +762,10 @@ fn F[T:! Ptr](var t: T) -> T.(Ptr.Type) {
 // CHECK:STDOUT:   %T.as_wit.iface0.loc22_11.2: <witness> = facet_access_witness %T.loc14_6.2, element0 [symbolic = %T.as_wit.iface0.loc22_11.2 (constants.%T.as_wit.iface0)]
 // CHECK:STDOUT:   %impl.elem0.loc22_11.2: type = impl_witness_access %T.as_wit.iface0.loc22_11.2, element0 [symbolic = %impl.elem0.loc22_11.2 (constants.%impl.elem0.44a)]
 // CHECK:STDOUT:   %require_complete.loc22_11: <witness> = require_complete_type %impl.elem0.loc22_11.2 [symbolic = %require_complete.loc22_11 (constants.%require_complete.b00)]
-// CHECK:STDOUT:   %ImplicitAs.type: type = facet_type <@ImplicitAs, @ImplicitAs(%impl.elem0.loc22_11.2)> [symbolic = %ImplicitAs.type (constants.%ImplicitAs.type.fb2)]
-// CHECK:STDOUT:   %require_complete.loc22_16: <witness> = require_complete_type %ImplicitAs.type [symbolic = %require_complete.loc22_16 (constants.%require_complete.462)]
+// CHECK:STDOUT:   %ImplicitAs.type.loc22_16.2: type = facet_type <@ImplicitAs, @ImplicitAs(%impl.elem0.loc22_11.2)> [symbolic = %ImplicitAs.type.loc22_16.2 (constants.%ImplicitAs.type.fb2)]
+// CHECK:STDOUT:   %require_complete.loc22_16: <witness> = require_complete_type %ImplicitAs.type.loc22_16.2 [symbolic = %require_complete.loc22_16 (constants.%require_complete.462)]
+// CHECK:STDOUT:   %ImplicitAs.assoc_type: type = assoc_entity_type @ImplicitAs, @ImplicitAs(%impl.elem0.loc22_11.2) [symbolic = %ImplicitAs.assoc_type (constants.%ImplicitAs.assoc_type.40d)]
+// CHECK:STDOUT:   %assoc0: @F.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.40d) = assoc_entity element0, imports.%Core.import_ref.1c7 [symbolic = %assoc0 (constants.%assoc0.763)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn(%T.patt.loc14_6.1: %Z.type.049, %t.param_patt: @F.%T.as_type.loc14_19.2 (%T.as_type)) {
 // CHECK:STDOUT:   !entry:
@@ -780,7 +782,10 @@ fn F[T:! Ptr](var t: T) -> T.(Ptr.Type) {
 // CHECK:STDOUT:       %T.as_wit.iface0.loc22_11.1: <witness> = facet_access_witness %T.ref.loc22, element0 [symbolic = %T.as_wit.iface0.loc22_11.2 (constants.%T.as_wit.iface0)]
 // CHECK:STDOUT:       %impl.elem0.loc22_11.1: type = impl_witness_access %T.as_wit.iface0.loc22_11.1, element0 [symbolic = %impl.elem0.loc22_11.2 (constants.%impl.elem0.44a)]
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %.loc22_16: @F.%impl.elem0.loc22_11.2 (%impl.elem0.44a) = converted %t.ref, <error> [concrete = <error>]
+// CHECK:STDOUT:     %ImplicitAs.type.loc22_16.1: type = facet_type <@ImplicitAs, @ImplicitAs(constants.%impl.elem0.44a)> [symbolic = %ImplicitAs.type.loc22_16.2 (constants.%ImplicitAs.type.fb2)]
+// CHECK:STDOUT:     %.loc22_16.1: @F.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.40d) = specific_constant imports.%Core.import_ref.492, @ImplicitAs(constants.%impl.elem0.44a) [symbolic = %assoc0 (constants.%assoc0.763)]
+// CHECK:STDOUT:     %Convert.ref: @F.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.40d) = name_ref Convert, %.loc22_16.1 [symbolic = %assoc0 (constants.%assoc0.763)]
+// CHECK:STDOUT:     %.loc22_16.2: @F.%impl.elem0.loc22_11.2 (%impl.elem0.44a) = converted %t.ref, <error> [concrete = <error>]
 // CHECK:STDOUT:     %a: @F.%impl.elem0.loc22_11.2 (%impl.elem0.44a) = bind_name a, <error>
 // CHECK:STDOUT:     return
 // CHECK:STDOUT:   }
@@ -1504,14 +1509,19 @@ fn F[T:! Ptr](var t: T) -> T.(Ptr.Type) {
 // CHECK:STDOUT:   %require_complete.loc9_25: <witness> = require_complete_type %impl.elem0.loc9_29.2 [symbolic = %require_complete.loc9_25 (constants.%require_complete.357)]
 // CHECK:STDOUT:   %require_complete.loc9_15: <witness> = require_complete_type %T.as_type.loc9_22.2 [symbolic = %require_complete.loc9_15 (constants.%require_complete.020)]
 // CHECK:STDOUT:   %ptr: type = ptr_type %T.as_type.loc9_22.2 [symbolic = %ptr (constants.%ptr.900)]
-// CHECK:STDOUT:   %ImplicitAs.type: type = facet_type <@ImplicitAs, @ImplicitAs(%impl.elem0.loc9_29.2)> [symbolic = %ImplicitAs.type (constants.%ImplicitAs.type.73f)]
-// CHECK:STDOUT:   %require_complete.loc17: <witness> = require_complete_type %ImplicitAs.type [symbolic = %require_complete.loc17 (constants.%require_complete.5f0)]
+// CHECK:STDOUT:   %ImplicitAs.type.loc17_12.2: type = facet_type <@ImplicitAs, @ImplicitAs(%impl.elem0.loc9_29.2)> [symbolic = %ImplicitAs.type.loc17_12.2 (constants.%ImplicitAs.type.73f)]
+// CHECK:STDOUT:   %require_complete.loc17: <witness> = require_complete_type %ImplicitAs.type.loc17_12.2 [symbolic = %require_complete.loc17 (constants.%require_complete.5f0)]
+// CHECK:STDOUT:   %ImplicitAs.assoc_type: type = assoc_entity_type @ImplicitAs, @ImplicitAs(%impl.elem0.loc9_29.2) [symbolic = %ImplicitAs.assoc_type (constants.%ImplicitAs.assoc_type.3d1)]
+// CHECK:STDOUT:   %assoc0: @F.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.3d1) = assoc_entity element0, imports.%Core.import_ref.1c7 [symbolic = %assoc0 (constants.%assoc0.802)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn[%T.patt.loc9_6.1: %Ptr.type](%.loc9_15: @F.%T.as_type.loc9_22.2 (%T.as_type)) -> @F.%impl.elem0.loc9_29.2 (%impl.elem0.9f2) {
 // CHECK:STDOUT:   !entry:
 // CHECK:STDOUT:     %t.ref: ref @F.%T.as_type.loc9_22.2 (%T.as_type) = name_ref t, %t
 // CHECK:STDOUT:     %addr: @F.%ptr (%ptr.900) = addr_of %t.ref
-// CHECK:STDOUT:     %.loc17: @F.%impl.elem0.loc9_29.2 (%impl.elem0.9f2) = converted %addr, <error> [concrete = <error>]
+// CHECK:STDOUT:     %ImplicitAs.type.loc17_12.1: type = facet_type <@ImplicitAs, @ImplicitAs(constants.%impl.elem0.9f2)> [symbolic = %ImplicitAs.type.loc17_12.2 (constants.%ImplicitAs.type.73f)]
+// CHECK:STDOUT:     %.loc17_12.1: @F.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.3d1) = specific_constant imports.%Core.import_ref.492, @ImplicitAs(constants.%impl.elem0.9f2) [symbolic = %assoc0 (constants.%assoc0.802)]
+// CHECK:STDOUT:     %Convert.ref: @F.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.3d1) = name_ref Convert, %.loc17_12.1 [symbolic = %assoc0 (constants.%assoc0.802)]
+// CHECK:STDOUT:     %.loc17_12.2: @F.%impl.elem0.loc9_29.2 (%impl.elem0.9f2) = converted %addr, <error> [concrete = <error>]
 // CHECK:STDOUT:     return <error>
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }

toolchain/check/testdata/impl/use_assoc_const.carbon

@@ -1973,8 +1973,15 @@ fn F() {
 // CHECK:STDOUT:   %impl.elem0.37e: type = impl_witness_access %T.as_wit.iface0, element0 [symbolic]
 // CHECK:STDOUT:   %specific_impl_fn: <specific function> = specific_impl_function %impl.elem1, @F(%J.facet.869) [symbolic]
 // CHECK:STDOUT:   %require_complete.8bd: <witness> = require_complete_type %impl.elem0.37e [symbolic]
+// CHECK:STDOUT:   %Dest: type = bind_symbolic_name Dest, 0 [symbolic]
+// CHECK:STDOUT:   %Convert.type.275: type = fn_type @Convert.1, @ImplicitAs(%Dest) [symbolic]
+// CHECK:STDOUT:   %Convert.42e: %Convert.type.275 = struct_value () [symbolic]
+// CHECK:STDOUT:   %ImplicitAs.assoc_type.ca0: type = assoc_entity_type @ImplicitAs, @ImplicitAs(%Dest) [symbolic]
 // CHECK:STDOUT:   %ImplicitAs.type.820: type = facet_type <@ImplicitAs, @ImplicitAs(%impl.elem0.37e)> [symbolic]
+// CHECK:STDOUT:   %ImplicitAs.assoc_type.cb0: type = assoc_entity_type @ImplicitAs, @ImplicitAs(%impl.elem0.37e) [symbolic]
+// CHECK:STDOUT:   %assoc0.37d: %ImplicitAs.assoc_type.cb0 = assoc_entity element0, imports.%Core.import_ref.1c7 [symbolic]
 // CHECK:STDOUT:   %require_complete.1ce: <witness> = require_complete_type %ImplicitAs.type.820 [symbolic]
+// CHECK:STDOUT:   %assoc0.dc0: %ImplicitAs.assoc_type.ca0 = assoc_entity element0, imports.%Core.import_ref.207 [symbolic]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
@@ -1984,6 +1991,8 @@ fn F() {
 // CHECK:STDOUT:     import Core//prelude
 // CHECK:STDOUT:     import Core//prelude/...
 // CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import_ref.492: @ImplicitAs.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.ca0) = import_ref Core//prelude/operators/as, loc13_35, loaded [symbolic = @ImplicitAs.%assoc0 (constants.%assoc0.dc0)]
+// CHECK:STDOUT:   %Core.import_ref.1c7: @ImplicitAs.%Convert.type (%Convert.type.275) = import_ref Core//prelude/operators/as, loc13_35, loaded [symbolic = @ImplicitAs.%Convert (constants.%Convert.42e)]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
@@ -2090,8 +2099,10 @@ fn F() {
 // CHECK:STDOUT:   %impl.elem0.1: type = impl_witness_access %T.as_wit.iface0.loc26_11.2, element0 [symbolic = %impl.elem0.1 (constants.%impl.elem0.37e)]
 // CHECK:STDOUT:   %specific_impl_fn.loc26_11.2: <specific function> = specific_impl_function %impl.elem1.loc26_11.2, @F(%J.facet) [symbolic = %specific_impl_fn.loc26_11.2 (constants.%specific_impl_fn)]
 // CHECK:STDOUT:   %require_complete.loc26_15: <witness> = require_complete_type %impl.elem0.1 [symbolic = %require_complete.loc26_15 (constants.%require_complete.8bd)]
-// CHECK:STDOUT:   %ImplicitAs.type: type = facet_type <@ImplicitAs, @ImplicitAs(%impl.elem0.1)> [symbolic = %ImplicitAs.type (constants.%ImplicitAs.type.820)]
-// CHECK:STDOUT:   %require_complete.loc26_14: <witness> = require_complete_type %ImplicitAs.type [symbolic = %require_complete.loc26_14 (constants.%require_complete.1ce)]
+// CHECK:STDOUT:   %ImplicitAs.type.loc26_14.2: type = facet_type <@ImplicitAs, @ImplicitAs(%impl.elem0.1)> [symbolic = %ImplicitAs.type.loc26_14.2 (constants.%ImplicitAs.type.820)]
+// CHECK:STDOUT:   %require_complete.loc26_14: <witness> = require_complete_type %ImplicitAs.type.loc26_14.2 [symbolic = %require_complete.loc26_14 (constants.%require_complete.1ce)]
+// CHECK:STDOUT:   %ImplicitAs.assoc_type: type = assoc_entity_type @ImplicitAs, @ImplicitAs(%impl.elem0.1) [symbolic = %ImplicitAs.assoc_type (constants.%ImplicitAs.assoc_type.cb0)]
+// CHECK:STDOUT:   %assoc0: @GenericCallFI32.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.cb0) = assoc_entity element0, imports.%Core.import_ref.1c7 [symbolic = %assoc0 (constants.%assoc0.37d)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn[%T.patt.loc8_20.1: %J_where.type](%t.param_patt: @GenericCallFI32.%T.as_type.loc8_45.2 (%T.as_type)) -> %i32 {
 // CHECK:STDOUT:   !entry:
@@ -2103,7 +2114,10 @@ fn F() {
 // CHECK:STDOUT:     %impl.elem1.loc26_11.1: @GenericCallFI32.%.loc26_11.2 (%.861) = impl_witness_access %T.as_wit.iface0.loc26_11.1, element1 [symbolic = %impl.elem1.loc26_11.2 (constants.%impl.elem1)]
 // CHECK:STDOUT:     %int_2: Core.IntLiteral = int_value 2 [concrete = constants.%int_2]
 // CHECK:STDOUT:     %specific_impl_fn.loc26_11.1: <specific function> = specific_impl_function %impl.elem1.loc26_11.1, @F(constants.%J.facet.869) [symbolic = %specific_impl_fn.loc26_11.2 (constants.%specific_impl_fn)]
-// CHECK:STDOUT:     %.loc26_14: @GenericCallFI32.%impl.elem0.1 (%impl.elem0.37e) = converted %int_2, <error> [concrete = <error>]
+// CHECK:STDOUT:     %ImplicitAs.type.loc26_14.1: type = facet_type <@ImplicitAs, @ImplicitAs(constants.%impl.elem0.37e)> [symbolic = %ImplicitAs.type.loc26_14.2 (constants.%ImplicitAs.type.820)]
+// CHECK:STDOUT:     %.loc26_14.1: @GenericCallFI32.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.cb0) = specific_constant imports.%Core.import_ref.492, @ImplicitAs(constants.%impl.elem0.37e) [symbolic = %assoc0 (constants.%assoc0.37d)]
+// CHECK:STDOUT:     %Convert.ref: @GenericCallFI32.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.cb0) = name_ref Convert, %.loc26_14.1 [symbolic = %assoc0 (constants.%assoc0.37d)]
+// CHECK:STDOUT:     %.loc26_14.2: @GenericCallFI32.%impl.elem0.1 (%impl.elem0.37e) = converted %int_2, <error> [concrete = <error>]
 // CHECK:STDOUT:     %.loc26_15: init @GenericCallFI32.%impl.elem0.1 (%impl.elem0.37e) = call %specific_impl_fn.loc26_11.1(<error>) [concrete = <error>]
 // CHECK:STDOUT:     %.loc26_16: %i32 = converted %.loc26_15, <error> [concrete = <error>]
 // CHECK:STDOUT:     return <error>

toolchain/check/testdata/let/fail_generic.carbon

@@ -39,6 +39,12 @@ fn F(a: i32) -> i32 {
 // CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic]
 // CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic]
 // CHECK:STDOUT:   %int_5: Core.IntLiteral = int_value 5 [concrete]
+// CHECK:STDOUT:   %Dest: type = bind_symbolic_name Dest, 0 [symbolic]
+// CHECK:STDOUT:   %ImplicitAs.assoc_type.ca0d85.1: type = assoc_entity_type @ImplicitAs, @ImplicitAs(%Dest) [symbolic]
+// CHECK:STDOUT:   %ImplicitAs.type.d628ce.2: type = facet_type <@ImplicitAs, @ImplicitAs(%T)> [symbolic]
+// CHECK:STDOUT:   %ImplicitAs.assoc_type.ca0d85.2: type = assoc_entity_type @ImplicitAs, @ImplicitAs(%T) [symbolic]
+// CHECK:STDOUT:   %assoc0.9f5e6b.2: %ImplicitAs.assoc_type.ca0d85.2 = assoc_entity element0, imports.%Core.import_ref.1c7 [symbolic]
+// CHECK:STDOUT:   %assoc0.dc0: %ImplicitAs.assoc_type.ca0d85.1 = assoc_entity element0, imports.%Core.import_ref.207 [symbolic]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
@@ -48,6 +54,7 @@ fn F(a: i32) -> i32 {
 // CHECK:STDOUT:     import Core//prelude
 // CHECK:STDOUT:     import Core//prelude/...
 // CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import_ref.492: @ImplicitAs.%ImplicitAs.assoc_type (%ImplicitAs.assoc_type.ca0d85.1) = import_ref Core//prelude/operators/as, loc13_35, loaded [symbolic = @ImplicitAs.%assoc0 (constants.%assoc0.dc0)]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
@@ -88,7 +95,10 @@ fn F(a: i32) -> i32 {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %int_5: Core.IntLiteral = int_value 5 [concrete = constants.%int_5]
 // CHECK:STDOUT:   %T.ref: type = name_ref T, %T [symbolic = constants.%T]
-// CHECK:STDOUT:   %.loc21: %T = converted %int_5, <error> [concrete = <error>]
+// CHECK:STDOUT:   %ImplicitAs.type: type = facet_type <@ImplicitAs, @ImplicitAs(constants.%T)> [symbolic = constants.%ImplicitAs.type.d628ce.2]
+// CHECK:STDOUT:   %.loc21_14.1: %ImplicitAs.assoc_type.ca0d85.2 = specific_constant imports.%Core.import_ref.492, @ImplicitAs(constants.%T) [symbolic = constants.%assoc0.9f5e6b.2]
+// CHECK:STDOUT:   %Convert.ref: %ImplicitAs.assoc_type.ca0d85.2 = name_ref Convert, %.loc21_14.1 [symbolic = constants.%assoc0.9f5e6b.2]
+// CHECK:STDOUT:   %.loc21_14.2: %T = converted %int_5, <error> [concrete = <error>]
 // CHECK:STDOUT:   %x: %T = bind_name x, <error>
 // CHECK:STDOUT:   %x.ref: %T = name_ref x, %x
 // CHECK:STDOUT:   %.loc29: %i32 = converted %x.ref, <error> [concrete = <error>]