Merge pull request #2462 from eeckstein/swift-merge-funcs

Add an LLVM pass to merge similar functions.

Author: eeckstein

include/swift/LLVMPasses/PassesFwd.h

@@ -25,13 +25,15 @@ namespace llvm {
   void initializeSwiftARCContractPass(PassRegistry &);
   void initializeSwiftStackPromotionPass(PassRegistry &);
   void initializeInlineTreePrinterPass(PassRegistry &);
+  void initializeSwiftMergeFunctionsPass(PassRegistry &);
 }
 
 namespace swift {
   llvm::FunctionPass *createSwiftARCOptPass();
   llvm::FunctionPass *createSwiftARCContractPass();
   llvm::FunctionPass *createSwiftStackPromotionPass();
   llvm::ModulePass *createInlineTreePrinterPass();
+  llvm::ModulePass *createSwiftMergeFunctionsPass();
   llvm::ImmutablePass *createSwiftAAWrapperPass();
   llvm::ImmutablePass *createSwiftRCIdentityPass();
 } // end namespace swift

lib/IRGen/IRGen.cpp

@@ -84,6 +84,12 @@ static void addSwiftStackPromotionPass(const PassManagerBuilder &Builder,
     PM.add(createSwiftStackPromotionPass());
 }
 
+static void addSwiftMergeFunctionsPass(const PassManagerBuilder &Builder,
+                                       PassManagerBase &PM) {
+  if (Builder.OptLevel > 0)
+    PM.add(createSwiftMergeFunctionsPass());
+}
+
 static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
                                       legacy::PassManagerBase &PM) {
   PM.add(createAddressSanitizerFunctionPass());
@@ -163,6 +169,8 @@ void swift::performLLVMOptimizations(IRGenOptions &Opts, llvm::Module *Module,
     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
                            addThreadSanitizerPass);
   }
+  PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
+                         addSwiftMergeFunctionsPass);
 
   // Configure the function passes.
   legacy::FunctionPassManager FunctionPasses(Module);

lib/LLVMPasses/CMakeLists.txt

@@ -5,6 +5,7 @@ add_swift_library(swiftLLVMPasses
   LLVMARCContract.cpp
   LLVMInlineTree.cpp
   LLVMStackPromotion.cpp
+  LLVMMergeFunctions.cpp
   )
 
 add_dependencies(swiftLLVMPasses LLVMAnalysis)