diff --git a/gen/optimizer.cpp b/gen/optimizer.cpp index 7df169b7..beddeade 100644 --- a/gen/optimizer.cpp +++ b/gen/optimizer.cpp @@ -222,6 +222,9 @@ static void addPassesForOptLevel(PassManager& pm) { } if (optimizeLevel >= 1) { +#if LLVM_REV >= 68940 + addPass(pm, createStripExternalsPass()); +#endif addPass(pm, createGlobalDCEPass()); } diff --git a/gen/passes/Passes.h b/gen/passes/Passes.h index 6a58b57b..118ca759 100644 --- a/gen/passes/Passes.h +++ b/gen/passes/Passes.h @@ -12,8 +12,11 @@ llvm::FunctionPass* createSimplifyDRuntimeCalls(); #ifdef USE_METADATA llvm::FunctionPass* createGarbageCollect2Stack(); -llvm::ModulePass *createStripMetaData(); +llvm::ModulePass* createStripMetaData(); #endif +#if LLVM_REV >= 68940 +llvm::ModulePass* createStripExternalsPass(); +#endif #endif diff --git a/gen/passes/StripExternals.cpp b/gen/passes/StripExternals.cpp new file mode 100644 index 00000000..2ee2dde8 --- /dev/null +++ b/gen/passes/StripExternals.cpp @@ -0,0 +1,92 @@ +//===-- StripExternals.cpp - Strip available_externally symbols -----------===// +// +// The LLVM D Compiler +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This transform stips the bodies of available_externally functions and +// initializers of available_externally globals, turning them into external +// declarations. +// This is useful to allow Global DCE (-globaldce) to clean up references to +// globals only used by available_externally functions and initializers. +// +//===----------------------------------------------------------------------===// + +#include "gen/llvm-version.h" + +#if LLVM_REV >= 68940 + + +#define DEBUG_TYPE "strip-externals" + +#include "Passes.h" + +#include "llvm/Module.h" +#include "llvm/Pass.h" +#include "llvm/ADT/Statistic.h" +#include "llvm/Support/Compiler.h" +#include "llvm/Support/Debug.h" +using namespace llvm; + +STATISTIC(NumFunctions, "Number of function bodies removed"); +STATISTIC(NumVariables, "Number of global initializers removed"); + +namespace { + struct VISIBILITY_HIDDEN StripExternals : public ModulePass { + static char ID; // Pass identification, replacement for typeid + StripExternals() : ModulePass(&ID) {} + + // run - Do the StripExternals pass on the specified module. + // + bool runOnModule(Module &M); + }; +} + +char StripExternals::ID = 0; +static RegisterPass +X("strip-externals", "Strip available_externally bodies and initializers"); + +ModulePass *createStripExternalsPass() { return new StripExternals(); } + +bool StripExternals::runOnModule(Module &M) { + bool Changed = false; + + for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) { + if (I->hasAvailableExternallyLinkage()) { + assert(!I->isDeclaration()&&"Declarations can't be available_externally"); + Changed = true; + ++NumFunctions; + if (I->use_empty()) { + DOUT << "Deleting function: " << *I; + I->eraseFromParent(); + } else { + I->deleteBody(); + DOUT << "Deleted function body: " << *I; + } + } + } + + for (Module::global_iterator I = M.global_begin(), E = M.global_end(); + I != E; ++I) { + if (I->hasAvailableExternallyLinkage()) { + assert(!I->isDeclaration()&&"Declarations can't be available_externally"); + Changed = true; + ++NumVariables; + if (I->use_empty()) { + DOUT << "Deleting global: " << *I; + I->eraseFromParent(); + } else { + I->setInitializer(0); + I->setLinkage(GlobalValue::ExternalLinkage); + DOUT << "Deleted initializer: " << *I; + } + } + } + + return Changed; +} + +#endif //LLVM_REV >= 68940