Index: include/llvm/LTO/LTOCodeGenerator.h =================================================================== --- include/llvm/LTO/LTOCodeGenerator.h +++ include/llvm/LTO/LTOCodeGenerator.h @@ -174,10 +174,6 @@ bool compileOptimizedToFile(const char **Name); void restoreLinkageForExternals(); void applyScopeRestrictions(); - void applyRestriction(GlobalValue &GV, ArrayRef Libcalls, - std::vector &MustPreserveList, - SmallPtrSetImpl &AsmUsed, - Mangler &Mangler); bool determineTarget(); static void DiagnosticHandler(const DiagnosticInfo &DI, void *Context); Index: lib/LTO/CMakeLists.txt =================================================================== --- lib/LTO/CMakeLists.txt +++ lib/LTO/CMakeLists.txt @@ -2,6 +2,7 @@ LTOModule.cpp LTOCodeGenerator.cpp ThinLTOCodeGenerator.cpp + LTOInternalize.cpp ADDITIONAL_HEADER_DIRS ${LLVM_MAIN_INCLUDE_DIR}/llvm/LTO Index: lib/LTO/LTOCodeGenerator.cpp =================================================================== --- lib/LTO/LTOCodeGenerator.cpp +++ lib/LTO/LTOCodeGenerator.cpp @@ -13,6 +13,8 @@ //===----------------------------------------------------------------------===// #include "llvm/LTO/LTOCodeGenerator.h" + +#include "LTOInternalize.h" #include "llvm/ADT/Statistic.h" #include "llvm/ADT/StringExtras.h" #include "llvm/Analysis/Passes.h" @@ -331,145 +333,13 @@ return true; } -void LTOCodeGenerator:: -applyRestriction(GlobalValue &GV, - ArrayRef Libcalls, - std::vector &MustPreserveList, - SmallPtrSetImpl &AsmUsed, - Mangler &Mangler) { - // There are no restrictions to apply to declarations. - if (GV.isDeclaration()) - return; - - // There is nothing more restrictive than private linkage. - if (GV.hasPrivateLinkage()) - return; - - SmallString<64> Buffer; - TargetMach->getNameWithPrefix(Buffer, &GV, Mangler); - - if (MustPreserveSymbols.count(Buffer)) - MustPreserveList.push_back(GV.getName().data()); - if (AsmUndefinedRefs.count(Buffer)) - AsmUsed.insert(&GV); - - // Conservatively append user-supplied runtime library functions to - // llvm.compiler.used. These could be internalized and deleted by - // optimizations like -globalopt, causing problems when later optimizations - // add new library calls (e.g., llvm.memset => memset and printf => puts). - // Leave it to the linker to remove any dead code (e.g. with -dead_strip). - if (isa(GV) && - std::binary_search(Libcalls.begin(), Libcalls.end(), GV.getName())) - AsmUsed.insert(&GV); - - // Record the linkage type of non-local symbols so they can be restored prior - // to module splitting. - if (ShouldRestoreGlobalsLinkage && !GV.hasAvailableExternallyLinkage() && - !GV.hasLocalLinkage() && GV.hasName()) - ExternalSymbols.insert(std::make_pair(GV.getName(), GV.getLinkage())); -} - -static void findUsedValues(GlobalVariable *LLVMUsed, - SmallPtrSetImpl &UsedValues) { - if (!LLVMUsed) return; - - ConstantArray *Inits = cast(LLVMUsed->getInitializer()); - for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i) - if (GlobalValue *GV = - dyn_cast(Inits->getOperand(i)->stripPointerCasts())) - UsedValues.insert(GV); -} - -// Collect names of runtime library functions. User-defined functions with the -// same names are added to llvm.compiler.used to prevent them from being -// deleted by optimizations. -static void accumulateAndSortLibcalls(std::vector &Libcalls, - const TargetLibraryInfo& TLI, - const Module &Mod, - const TargetMachine &TM) { - // TargetLibraryInfo has info on C runtime library calls on the current - // target. - for (unsigned I = 0, E = static_cast(LibFunc::NumLibFuncs); - I != E; ++I) { - LibFunc::Func F = static_cast(I); - if (TLI.has(F)) - Libcalls.push_back(TLI.getName(F)); - } - - SmallPtrSet TLSet; - - for (const Function &F : Mod) { - const TargetLowering *Lowering = - TM.getSubtargetImpl(F)->getTargetLowering(); - - if (Lowering && TLSet.insert(Lowering).second) - // TargetLowering has info on library calls that CodeGen expects to be - // available, both from the C runtime and compiler-rt. - for (unsigned I = 0, E = static_cast(RTLIB::UNKNOWN_LIBCALL); - I != E; ++I) - if (const char *Name = - Lowering->getLibcallName(static_cast(I))) - Libcalls.push_back(Name); - } - - array_pod_sort(Libcalls.begin(), Libcalls.end()); - Libcalls.erase(std::unique(Libcalls.begin(), Libcalls.end()), - Libcalls.end()); -} - void LTOCodeGenerator::applyScopeRestrictions() { if (ScopeRestrictionsDone || !ShouldInternalize) return; - // Start off with a verification pass. - legacy::PassManager passes; - passes.add(createVerifierPass()); - - // mark which symbols can not be internalized - Mangler Mangler; - std::vector MustPreserveList; - SmallPtrSet AsmUsed; - std::vector Libcalls; - TargetLibraryInfoImpl TLII(Triple(TargetMach->getTargetTriple())); - TargetLibraryInfo TLI(TLII); - - accumulateAndSortLibcalls(Libcalls, TLI, *MergedModule, *TargetMach); - - for (Function &f : *MergedModule) - applyRestriction(f, Libcalls, MustPreserveList, AsmUsed, Mangler); - for (GlobalVariable &v : MergedModule->globals()) - applyRestriction(v, Libcalls, MustPreserveList, AsmUsed, Mangler); - for (GlobalAlias &a : MergedModule->aliases()) - applyRestriction(a, Libcalls, MustPreserveList, AsmUsed, Mangler); - - GlobalVariable *LLVMCompilerUsed = - MergedModule->getGlobalVariable("llvm.compiler.used"); - findUsedValues(LLVMCompilerUsed, AsmUsed); - if (LLVMCompilerUsed) - LLVMCompilerUsed->eraseFromParent(); - - if (!AsmUsed.empty()) { - llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(Context); - std::vector asmUsed2; - for (auto *GV : AsmUsed) { - Constant *c = ConstantExpr::getBitCast(GV, i8PTy); - asmUsed2.push_back(c); - } - - llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, asmUsed2.size()); - LLVMCompilerUsed = - new llvm::GlobalVariable(*MergedModule, ATy, false, - llvm::GlobalValue::AppendingLinkage, - llvm::ConstantArray::get(ATy, asmUsed2), - "llvm.compiler.used"); - - LLVMCompilerUsed->setSection("llvm.metadata"); - } - - passes.add(createInternalizePass(MustPreserveList)); - - // apply scope restrictions - passes.run(*MergedModule); + LTOInternalize(*MergedModule, *TargetMach, MustPreserveSymbols, + AsmUndefinedRefs, + (ShouldRestoreGlobalsLinkage ? &ExternalSymbols : nullptr)); ScopeRestrictionsDone = true; } @@ -510,6 +380,11 @@ if (!this->determineTarget()) return false; + // We always run the verifier once on the merged module, the `DisableVerify` + // parameter only applies to subsequent verify. + if (verifyModule(*MergedModule, &dbgs())) + report_fatal_error("Broken module found, compilation aborted!"); + // Mark which symbols can not be internalized this->applyScopeRestrictions(); Index: lib/LTO/LTOInternalize.h =================================================================== --- /dev/null +++ lib/LTO/LTOInternalize.h @@ -0,0 +1,30 @@ +//===-LTOInternalize.h - LLVM Link Time Optimizer Internalization Utility -===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file declares a helper class to run the internalization part of LTO. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_LTO_LTOINTERNALIZE_H +#define LLVM_LTO_LTOINTERNALIZE_H + +#include "llvm/ADT/StringSet.h" +#include "llvm/IR/GlobalValue.h" + +namespace llvm { +class Module; +class TargetMachine; + +void LTOInternalize(Module &TheModule, TargetMachine &TM, + const StringSet<> &MustPreserveSymbols, + const StringSet<> &AsmUndefinedRefs, + StringMap *ExternalSymbols); +} + +#endif // LLVM_LTO_LTOINTERNALIZE_H Index: lib/LTO/LTOInternalize.cpp =================================================================== --- /dev/null +++ lib/LTO/LTOInternalize.cpp @@ -0,0 +1,189 @@ +//==-LTOInternalize.cpp - LLVM Link Time Optimizer Internalization Utility -==// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines a helper to run the internalization part of LTO. +// +//===----------------------------------------------------------------------===// + +#include "LTOInternalize.h" + +#include "llvm/Analysis/TargetLibraryInfo.h" +#include "llvm/IR/LegacyPassManager.h" +#include "llvm/IR/Mangler.h" +#include "llvm/Target/TargetLowering.h" +#include "llvm/Target/TargetSubtargetInfo.h" +#include "llvm/Transforms/IPO.h" + +using namespace llvm; + +namespace { + +class ComputePreserveList { +public: + ComputePreserveList(const StringSet<> &MustPreserveSymbols, + const StringSet<> &AsmUndefinedRefs, + const TargetMachine &TM, const Module &TheModule, + StringMap *ExternalSymbols, + std::vector &MustPreserveList, + SmallPtrSetImpl &AsmUsed) + : MustPreserveSymbols(MustPreserveSymbols), + AsmUndefinedRefs(AsmUndefinedRefs), TM(TM), + ExternalSymbols(ExternalSymbols), MustPreserveList(MustPreserveList), + AsmUsed(AsmUsed) { + accumulateAndSortLibcalls(TheModule); + for (const Function &F : TheModule) + applyRestriction(F); + for (const GlobalVariable &GV : TheModule.globals()) + applyRestriction(GV); + for (const GlobalAlias &GA : TheModule.aliases()) + applyRestriction(GA); + } + +private: + // Inputs + const StringSet<> &MustPreserveSymbols; + const StringSet<> AsmUndefinedRefs; + const TargetMachine &TM; + + // Temps + Mangler Mangler; + std::vector Libcalls; + + // Output + StringMap *ExternalSymbols; + std::vector &MustPreserveList; + SmallPtrSetImpl &AsmUsed; + + // Collect names of runtime library functions. User-defined functions with the + // same names are added to llvm.compiler.used to prevent them from being + // deleted by optimizations. + void accumulateAndSortLibcalls(const Module &TheModule) { + TargetLibraryInfoImpl TLII(Triple(TM.getTargetTriple())); + TargetLibraryInfo TLI(TLII); + + // TargetLibraryInfo has info on C runtime library calls on the current + // target. + for (unsigned I = 0, E = static_cast(LibFunc::NumLibFuncs); + I != E; ++I) { + LibFunc::Func F = static_cast(I); + if (TLI.has(F)) + Libcalls.push_back(TLI.getName(F)); + } + + SmallPtrSet TLSet; + + for (const Function &F : TheModule) { + const TargetLowering *Lowering = + TM.getSubtargetImpl(F)->getTargetLowering(); + + if (Lowering && TLSet.insert(Lowering).second) + // TargetLowering has info on library calls that CodeGen expects to be + // available, both from the C runtime and compiler-rt. + for (unsigned I = 0, E = static_cast(RTLIB::UNKNOWN_LIBCALL); + I != E; ++I) + if (const char *Name = + Lowering->getLibcallName(static_cast(I))) + Libcalls.push_back(Name); + } + + array_pod_sort(Libcalls.begin(), Libcalls.end()); + Libcalls.erase(std::unique(Libcalls.begin(), Libcalls.end()), + Libcalls.end()); + } + + void applyRestriction(const GlobalValue &GV) { + // There are no restrictions to apply to declarations. + if (GV.isDeclaration()) + return; + + // There is nothing more restrictive than private linkage. + if (GV.hasPrivateLinkage()) + return; + + SmallString<64> Buffer; + TM.getNameWithPrefix(Buffer, &GV, Mangler); + + if (MustPreserveSymbols.count(Buffer)) + MustPreserveList.push_back(GV.getName().data()); + if (AsmUndefinedRefs.count(Buffer)) + AsmUsed.insert(&GV); + + // Conservatively append user-supplied runtime library functions to + // llvm.compiler.used. These could be internalized and deleted by + // optimizations like -globalopt, causing problems when later optimizations + // add new library calls (e.g., llvm.memset => memset and printf => puts). + // Leave it to the linker to remove any dead code (e.g. with -dead_strip). + if (isa(GV) && + std::binary_search(Libcalls.begin(), Libcalls.end(), GV.getName())) + AsmUsed.insert(&GV); + + // Record the linkage type of non-local symbols so they can be restored + // prior + // to module splitting. + if (ExternalSymbols && !GV.hasAvailableExternallyLinkage() && + !GV.hasLocalLinkage() && GV.hasName()) + ExternalSymbols->insert(std::make_pair(GV.getName(), GV.getLinkage())); + } +}; + +} // namespace anonymous + +static void findUsedValues(GlobalVariable *LLVMUsed, + SmallPtrSetImpl &UsedValues) { + if (!LLVMUsed) + return; + + ConstantArray *Inits = cast(LLVMUsed->getInitializer()); + for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i) + if (GlobalValue *GV = + dyn_cast(Inits->getOperand(i)->stripPointerCasts())) + UsedValues.insert(GV); +} + +void llvm::LTOInternalize( + Module &TheModule, TargetMachine &TM, + const StringSet<> &MustPreserveSymbols, const StringSet<> &AsmUndefinedRefs, + StringMap *ExternalSymbols) { + legacy::PassManager passes; + // mark which symbols can not be internalized + Mangler Mangler; + std::vector MustPreserveList; + SmallPtrSet AsmUsed; + + ComputePreserveList(MustPreserveSymbols, AsmUndefinedRefs, TM, TheModule, + ExternalSymbols, MustPreserveList, AsmUsed); + + GlobalVariable *LLVMCompilerUsed = + TheModule.getGlobalVariable("llvm.compiler.used"); + findUsedValues(LLVMCompilerUsed, AsmUsed); + if (LLVMCompilerUsed) + LLVMCompilerUsed->eraseFromParent(); + + if (!AsmUsed.empty()) { + llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(TheModule.getContext()); + std::vector asmUsed2; + for (const auto *GV : AsmUsed) { + Constant *c = + ConstantExpr::getBitCast(const_cast(GV), i8PTy); + asmUsed2.push_back(c); + } + + llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, asmUsed2.size()); + LLVMCompilerUsed = new llvm::GlobalVariable( + TheModule, ATy, false, llvm::GlobalValue::AppendingLinkage, + llvm::ConstantArray::get(ATy, asmUsed2), "llvm.compiler.used"); + + LLVMCompilerUsed->setSection("llvm.metadata"); + } + + passes.add(createInternalizePass(MustPreserveList)); + + // apply scope restrictions + passes.run(TheModule); +} Index: test/LTO/X86/disable-verify.ll =================================================================== --- test/LTO/X86/disable-verify.ll +++ test/LTO/X86/disable-verify.ll @@ -6,10 +6,10 @@ target triple = "x86_64-apple-macosx10.10.0" ; -disable-verify should disable verification from the optimization pipeline. -; CHECK: Pass Arguments: -verify -internalize +; CHECK: Pass Arguments: -internalize ; CHECK-NOT: -verify -; VERIFY: Pass Arguments: -verify -internalize +; VERIFY: Pass Arguments: -internalize ; VERIFY: Pass Arguments: {{.*}} -verify {{.*}} -verify define void @f() {