Optimizer: add TypeSubstitutionCloner and func cloneAndSpecializeFunction

Also move `func cloneFunction` from ContextCommon.swift to OptUtils.swift

Author: eeckstein

SwiftCompilerSources/Sources/Optimizer/PassManager/ContextCommon.swift

@@ -163,9 +163,3 @@ extension Instruction {
     context.notifyInstructionsChanged()
   }
 }
-
-func cloneFunction(from originalFunction: Function, toEmpty targetFunction: Function, _ context: FunctionPassContext) {
-  var cloner = Cloner(cloneToEmptyFunction: targetFunction, context)
-  defer { cloner.deinitialize() }
-  cloner.cloneFunctionBody(from: originalFunction)
-}

SwiftCompilerSources/Sources/Optimizer/Utilities/OptUtils.swift

@@ -1092,3 +1092,20 @@ func isInLoop(block startBlock: BasicBlock, _ context: FunctionPassContext) -> B
   }
   return false
 }
+
+func cloneFunction(from originalFunction: Function, toEmpty targetFunction: Function, _ context: FunctionPassContext) {
+  var cloner = Cloner(cloneToEmptyFunction: targetFunction, context)
+  defer { cloner.deinitialize() }
+  cloner.cloneFunctionBody(from: originalFunction)
+}
+
+func cloneAndSpecializeFunction(from originalFunction: Function,
+                                toEmpty targetFunction: Function,
+                                substitutions: SubstitutionMap,
+                                _ context: FunctionPassContext
+) {
+  var cloner = TypeSubstitutionCloner(fromFunction: originalFunction, toEmptyFunction: targetFunction,
+                                      substitutions: substitutions, context)
+  defer { cloner.deinitialize() }
+  cloner.cloneFunctionBody()
+}

SwiftCompilerSources/Sources/SIL/Utilities/Cloner.swift

@@ -11,6 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 import SILBridging
+import AST
 
 /// Clones the initializer value of a GlobalVariable.
 ///
@@ -161,3 +162,34 @@ public struct Cloner<Context: MutatingContext> {
     bridged.recordFoldedValue(origValue.bridged, mappedValue.bridged)
   }
 }
+
+public struct TypeSubstitutionCloner<Context: MutatingContext> {
+  public private(set) var bridged: BridgedTypeSubstCloner
+  public let context: Context
+
+  public init(fromFunction: Function,
+              toEmptyFunction: Function,
+              substitutions: SubstitutionMap, _ context: Context
+  ) {
+    context.verifyIsTransforming(function: toEmptyFunction)
+    self.bridged = BridgedTypeSubstCloner(fromFunction.bridged, toEmptyFunction.bridged,
+                                          substitutions.bridged, context._bridged)
+    self.context = context
+  }
+
+  public mutating func deinitialize() {
+    bridged.destroy(context._bridged)
+  }
+
+  public mutating func getClonedValue(of originalValue: Value) -> Value {
+    bridged.getClonedValue(originalValue.bridged).value
+  }
+
+  public func getClonedBlock(for originalBlock: BasicBlock) -> BasicBlock {
+    bridged.getClonedBasicBlock(originalBlock.bridged).block
+  }
+
+  public func cloneFunctionBody() {
+    bridged.cloneFunctionBody()
+  }
+}

include/swift/SIL/SILBridging.h

@@ -63,6 +63,7 @@ class SILDefaultWitnessTable;
 class SILLoopInfo;
 class SILLoop;
 class BridgedClonerImpl;
+class BridgedTypeSubstClonerImpl;
 class SILDebugLocation;
 class NominalTypeDecl;
 class VarDecl;
@@ -1541,6 +1542,17 @@ struct BridgedCloner {
   BridgedInstruction clone(BridgedInstruction inst) const;
 };
 
+struct BridgedTypeSubstCloner {
+  swift::BridgedTypeSubstClonerImpl * _Nonnull cloner;
+
+  BridgedTypeSubstCloner(BridgedFunction fromFunction, BridgedFunction toFunction,
+                         BridgedSubstitutionMap substitutions, BridgedContext context);
+  void destroy(BridgedContext context);
+  void cloneFunctionBody() const;
+  SWIFT_IMPORT_UNSAFE BridgedBasicBlock getClonedBasicBlock(BridgedBasicBlock originalBasicBlock) const;
+  SWIFT_IMPORT_UNSAFE BridgedValue getClonedValue(BridgedValue v);
+};
+
 struct BridgedVerifier {
   typedef void (* _Nonnull VerifyFunctionFn)(BridgedContext, BridgedFunction);
 

lib/SIL/Utils/SILBridging.cpp

@@ -22,6 +22,7 @@
 #include "swift/Basic/Assertions.h"
 #include "swift/SIL/SILContext.h"
 #include "swift/SIL/SILCloner.h"
+#include "swift/SIL/TypeSubstCloner.h"
 #include "swift/SIL/MemAccessUtils.h"
 #include "swift/SIL/OwnershipUtils.h"
 #include "swift/SIL/ParseTestSpecification.h"
@@ -620,7 +621,32 @@ class BridgedClonerImpl : public SILCloner<BridgedClonerImpl> {
     result = Cloned;
     SILCloner<BridgedClonerImpl>::postProcess(Orig, Cloned);
   }
+};
+
+class BridgedTypeSubstClonerImpl : public TypeSubstCloner<BridgedTypeSubstClonerImpl> {
+  SILInstruction *result = nullptr;
+
+public:
+  BridgedTypeSubstClonerImpl(SILFunction &from, SILFunction &toEmptyFunction, SubstitutionMap subs)
+    : TypeSubstCloner<BridgedTypeSubstClonerImpl>(toEmptyFunction, from, subs) {}
+
+  SILValue getClonedValue(SILValue v) {
+    return getMappedValue(v);
+  }
+
+  SILInstruction *cloneInst(SILInstruction *inst) {
+    result = nullptr;
+    visit(inst);
+    ASSERT(result && "instruction not cloned");
+    return result;
+  }
+
+  void postProcess(SILInstruction *Orig, SILInstruction *Cloned) {
+    result = Cloned;
+    SILClonerWithScopes<BridgedTypeSubstClonerImpl>::postProcess(Orig, Cloned);
+  }
 
+  SILFunction *getOriginal() { return &Original; }
 };
 
 } // namespace swift
@@ -687,6 +713,32 @@ void BridgedCloner::cloneFunctionBody(BridgedFunction originalFunction) const {
   cloner->cloneFunction(originalFunction.getFunction());
 }
 
+BridgedTypeSubstCloner::BridgedTypeSubstCloner(BridgedFunction fromFunction, BridgedFunction toFunction,
+                                               BridgedSubstitutionMap substitutions,
+                                               BridgedContext context)
+  : cloner(new BridgedTypeSubstClonerImpl(*fromFunction.getFunction(), *toFunction.getFunction(),
+                                          substitutions.unbridged())) {
+  context.context->notifyNewCloner();
+}
+
+void BridgedTypeSubstCloner::destroy(BridgedContext context) {
+  delete cloner;
+  cloner = nullptr;
+  context.context->notifyClonerDestroyed();
+}
+
+void BridgedTypeSubstCloner::cloneFunctionBody() const {
+  cloner->cloneFunction(cloner->getOriginal());
+}
+
+BridgedBasicBlock BridgedTypeSubstCloner::getClonedBasicBlock(BridgedBasicBlock originalBasicBlock) const {
+  return { cloner->getOpBasicBlock(originalBasicBlock.unbridged()) };
+}
+
+BridgedValue BridgedTypeSubstCloner::getClonedValue(BridgedValue v) {
+  return {cloner->getClonedValue(v.getSILValue())};
+}
+
 //===----------------------------------------------------------------------===//
 //                               BridgedContext
 //===----------------------------------------------------------------------===//