Move the Swift function-merging pass to LLVM

include/llvm/InitializePasses.h

@@ -272,6 +272,7 @@ void initializeMemorySSAPrinterLegacyPassPass(PassRegistry&);
 void initializeMemorySSAWrapperPassPass(PassRegistry&);
 void initializeMemorySanitizerPass(PassRegistry&);
 void initializeMergeFunctionsPass(PassRegistry&);
+void initializeMergeSimilarFunctionsPass(PassRegistry &);
 void initializeMergeICmpsPass(PassRegistry&);
 void initializeMergedLoadStoreMotionLegacyPassPass(PassRegistry&);
 void initializeMetaRenamerPass(PassRegistry&);

include/llvm/LinkAllPasses.h

@@ -189,6 +189,7 @@ namespace {
       (void) llvm::createPostOrderFunctionAttrsLegacyPass();
       (void) llvm::createReversePostOrderFunctionAttrsPass();
       (void) llvm::createMergeFunctionsPass();
+      (void)llvm::createMergeSimilarFunctionsPass();
       (void) llvm::createMergeICmpsPass();
       (void) llvm::createExpandMemCmpPass();
       std::string buf;

include/llvm/Transforms/IPO.h

@@ -201,6 +201,12 @@ Pass *createReversePostOrderFunctionAttrsPass();
 ///
 ModulePass *createMergeFunctionsPass();
 
+//===----------------------------------------------------------------------===//
+/// createMergeSimilarFunctionsPass - This pass discovers similar functions and
+/// collapses them.
+///
+ModulePass *createMergeSimilarFunctionsPass();
+
 //===----------------------------------------------------------------------===//
 /// createHotColdSplittingPass - This pass outlines cold blocks into a separate
 /// function(s).

include/llvm/Transforms/IPO/PassManagerBuilder.h

@@ -153,6 +153,7 @@ class PassManagerBuilder {
   bool VerifyInput;
   bool VerifyOutput;
   bool MergeFunctions;
+  bool MergeSimilarFunctions;
   bool PrepareForLTO;
   bool PrepareForThinLTO;
   bool PerformThinLTO;

lib/Transforms/IPO/CMakeLists.txt

@@ -25,6 +25,7 @@ add_llvm_library(LLVMipo
   LoopExtractor.cpp
   LowerTypeTests.cpp
   MergeFunctions.cpp
+  MergeSimilarFunctions.cpp
   PartialInlining.cpp
   PassManagerBuilder.cpp
   PruneEH.cpp

lib/Transforms/IPO/IPO.cpp

@@ -45,6 +45,7 @@ void llvm::initializeIPO(PassRegistry &Registry) {
   initializeSingleLoopExtractorPass(Registry);
   initializeLowerTypeTestsPass(Registry);
   initializeMergeFunctionsPass(Registry);
+  initializeMergeSimilarFunctionsPass(Registry);
   initializePartialInlinerLegacyPassPass(Registry);
   initializePostOrderFunctionAttrsLegacyPassPass(Registry);
   initializeReversePostOrderFunctionAttrsLegacyPassPass(Registry);