Optimizer: add FunctionPassContext.mangle(withChangedRepresentation original: Function)

Author: eeckstein

SwiftCompilerSources/Sources/Optimizer/PassManager/FunctionPassContext.swift

@@ -164,6 +164,10 @@ struct FunctionPassContext : MutatingContext {
     }
   }
 
+  func mangle(withChangedRepresentation original: Function) -> String {
+    String(taking: bridgedPassContext.mangleWithChangedRepresentation(original.bridged))
+  }
+
   func createSpecializedFunctionDeclaration(
     from original: Function, withName specializedFunctionName: String,
     withParams specializedParameters: [ParameterInfo],

include/swift/SILOptimizer/OptimizerBridging.h

@@ -202,6 +202,7 @@ struct BridgedPassContext {
                                                       BridgedFunction bridgedOriginalFunction) const;
   BridgedOwnedString mangleWithExplodedPackArgs(BridgedArrayRef bridgedPackArgs,
                                                 BridgedFunction applySiteCallee) const;
+  BridgedOwnedString mangleWithChangedRepresentation(BridgedFunction applySiteCallee) const;
 
   void inlineFunction(BridgedInstruction apply, bool mandatoryInline) const;
   BRIDGED_INLINE bool eliminateDeadAllocations(BridgedFunction f) const;

include/swift/SILOptimizer/Utils/SpecializationMangler.h

@@ -104,6 +104,8 @@ class FunctionSignatureSpecializationMangler : public SpecializationMangler {
 
   ReturnValueModifierIntBase ReturnValue;
 
+  bool changedRepresentation = false;
+
 public:
   FunctionSignatureSpecializationMangler(ASTContext &Ctx, SpecializationPass Pass,
                                          swift::SerializedKind_t Serialized,
@@ -123,6 +125,7 @@ class FunctionSignatureSpecializationMangler : public SpecializationMangler {
   void setArgumentBoxToStack(unsigned OrigArgIdx);
   void setArgumentInOutToOut(unsigned OrigArgIdx);
   void setReturnValueOwnedToUnowned();
+  void setChangedRepresentation() { changedRepresentation = true; }
 
   // For effects
   void setRemovedEffect(EffectKind effect);

lib/SILOptimizer/Utils/OptimizerBridging.cpp

@@ -351,6 +351,17 @@ BridgedOwnedString BridgedPassContext::mangleWithExplodedPackArgs(
   return BridgedOwnedString(mangler.mangle());
 }
 
+BridgedOwnedString BridgedPassContext::mangleWithChangedRepresentation(BridgedFunction applySiteCallee) const {
+  auto pass = Demangle::SpecializationPass::EmbeddedWitnessCallSpecialization;
+
+  Mangle::FunctionSignatureSpecializationMangler mangler(
+      applySiteCallee.getFunction()->getASTContext(),
+      pass, IsNotSerialized, applySiteCallee.getFunction());
+
+  mangler.setChangedRepresentation();
+  return BridgedOwnedString(mangler.mangle());
+}
+
 void BridgedPassContext::fixStackNesting(BridgedFunction function) const {
   switch (StackNesting::fixNesting(function.getFunction())) {
     case StackNesting::Changes::None:

lib/SILOptimizer/Utils/SpecializationMangler.cpp

@@ -352,6 +352,11 @@ std::string FunctionSignatureSpecializationMangler::mangle() {
   ArgOpStorage.clear();
   beginMangling();
 
+  if (changedRepresentation) {
+    appendSpecializationOperator("Tfr");
+    return finalize();
+  }
+
   for (unsigned i : indices(OrigArgs)) {
     mangleArgument(OrigArgs[i]);
   }