#include "llvm/Transforms/IPO/GlobalOpt.h"#include "IPOOptions.h"#include "llvm/ADT/DenseMap.h"#include "llvm/ADT/STLExtras.h"#include "llvm/ADT/SmallPtrSet.h"#include "llvm/ADT/SmallVector.h"#include "llvm/ADT/Statistic.h"#include "llvm/ADT/Twine.h"#include "llvm/ADT/iterator_range.h"#include "llvm/Analysis/BlockFrequencyInfo.h"#include "llvm/Analysis/ConstantFolding.h"#include "llvm/Analysis/MemoryBuiltins.h"#include "llvm/Analysis/TargetLibraryInfo.h"#include "llvm/Analysis/TargetTransformInfo.h"#include "llvm/Analysis/ValueTracking.h"#include "llvm/BinaryFormat/Dwarf.h"#include "llvm/IR/Attributes.h"#include "llvm/IR/BasicBlock.h"#include "llvm/IR/CallingConv.h"#include "llvm/IR/Constant.h"#include "llvm/IR/Constants.h"#include "llvm/IR/DataLayout.h"#include "llvm/IR/DebugInfoMetadata.h"#include "llvm/IR/DerivedTypes.h"#include "llvm/IR/Dominators.h"#include "llvm/IR/Function.h"#include "llvm/IR/GlobalAlias.h"#include "llvm/IR/GlobalValue.h"#include "llvm/IR/GlobalVariable.h"#include "llvm/IR/IRBuilder.h"#include "llvm/IR/InstrTypes.h"#include "llvm/IR/Instruction.h"#include "llvm/IR/Instructions.h"#include "llvm/IR/IntrinsicInst.h"#include "llvm/IR/Module.h"#include "llvm/IR/Operator.h"#include "llvm/IR/ProfDataUtils.h"#include "llvm/IR/Type.h"#include "llvm/IR/Use.h"#include "llvm/IR/User.h"#include "llvm/IR/Value.h"#include "llvm/IR/ValueHandle.h"#include "llvm/Support/AtomicOrdering.h"#include "llvm/Support/Casting.h"#include "llvm/Support/Debug.h"#include "llvm/Support/ErrorHandling.h"#include "llvm/Support/raw_ostream.h"#include "llvm/Transforms/IPO.h"#include "llvm/Transforms/Utils/CtorUtils.h"#include "llvm/Transforms/Utils/Evaluator.h"#include "llvm/Transforms/Utils/GlobalStatus.h"#include "llvm/Transforms/Utils/Local.h"#include <cassert>#include <cstdint>#include <optional>#include <utility>Go to the source code of this file.
Classes | |
| struct | GlobalPart |
| Part of the global at a specific offset, which is only accessed through loads and stores with the given type. More... | |
Macros | |
| #define | DEBUG_TYPE "globalopt" |
Typedefs | |
| using | ChangeableCCCacheTy = SmallDenseMap<Function *, bool, 8> |
Functions | |
| STATISTIC (NumMarked, "Number of globals marked constant") | |
| STATISTIC (NumUnnamed, "Number of globals marked unnamed_addr") | |
| STATISTIC (NumSRA, "Number of aggregate globals broken into scalars") | |
| STATISTIC (NumSubstitute,"Number of globals with initializers stored into them") | |
| STATISTIC (NumDeleted, "Number of globals deleted") | |
| STATISTIC (NumGlobUses, "Number of global uses devirtualized") | |
| STATISTIC (NumLocalized, "Number of globals localized") | |
| STATISTIC (NumShrunkToBool, "Number of global vars shrunk to booleans") | |
| STATISTIC (NumFastCallFns, "Number of functions converted to fastcc") | |
| STATISTIC (NumCtorsEvaluated, "Number of static ctors evaluated") | |
| STATISTIC (NumNestRemoved, "Number of nest attributes removed") | |
| STATISTIC (NumAliasesResolved, "Number of global aliases resolved") | |
| STATISTIC (NumAliasesRemoved, "Number of global aliases eliminated") | |
| STATISTIC (NumCXXDtorsRemoved, "Number of global C++ destructors removed") | |
| STATISTIC (NumAtExitRemoved, "Number of atexit handlers removed") | |
| STATISTIC (NumInternalFunc, "Number of internal functions") | |
| STATISTIC (NumColdCC, "Number of functions marked coldcc") | |
| STATISTIC (NumIFuncsResolved, "Number of statically resolved IFuncs") | |
| STATISTIC (NumIFuncsDeleted, "Number of IFuncs removed") | |
| static bool | isLeakCheckerRoot (GlobalVariable *GV) |
| Is this global variable possibly used by a leak checker as a root? | |
| static bool | IsSafeComputationToRemove (Value *V, function_ref< TargetLibraryInfo &(Function &)> GetTLI) |
| Given a value that is stored to a global but never read, determine whether it's safe to remove the store and the chain of computation that feeds the store. | |
| static bool | CleanupPointerRootUsers (GlobalVariable *GV, function_ref< TargetLibraryInfo &(Function &)> GetTLI) |
| This GV is a pointer root. | |
| static bool | CleanupConstantGlobalUsers (GlobalVariable *GV, const DataLayout &DL) |
| We just marked GV constant. | |
| static bool | collectSRATypes (DenseMap< uint64_t, GlobalPart > &Parts, GlobalVariable *GV, const DataLayout &DL) |
| Look at all uses of the global and determine which (offset, type) pairs it can be split into. | |
| static void | transferSRADebugInfo (GlobalVariable *GV, GlobalVariable *NGV, uint64_t FragmentOffsetInBits, uint64_t FragmentSizeInBits, uint64_t VarSize) |
| Copy over the debug info for a variable to its SRA replacements. | |
| static GlobalVariable * | SRAGlobal (GlobalVariable *GV, const DataLayout &DL) |
| Perform scalar replacement of aggregates on the specified global variable. | |
| static bool | OptimizeAwayTrappingUsesOfValue (Instruction *V, Constant *NewV) |
| static bool | OptimizeAwayTrappingUsesOfLoads (GlobalVariable *GV, Constant *LV, const DataLayout &DL, function_ref< TargetLibraryInfo &(Function &)> GetTLI) |
| The specified global has only one non-null value stored into it. | |
| static bool | optimizeOnceStoredGlobal (GlobalVariable *GV, Value *StoredOnceVal, const DataLayout &DL, function_ref< TargetLibraryInfo &(Function &)> GetTLI) |
| static bool | TryToShrinkGlobalToBoolean (GlobalVariable *GV, Constant *OtherVal) |
| At this point, we have learned that the only two values ever stored into GV are its initializer and OtherVal. | |
| static bool | deleteIfDead (GlobalValue &GV, SmallPtrSetImpl< const Comdat * > &NotDiscardableComdats, function_ref< void(Function &)> DeleteFnCallback=nullptr) |
| static bool | isPointerValueDeadOnEntryToFunction (const Function *F, GlobalValue *GV, function_ref< DominatorTree &(Function &)> LookupDomTree) |
| static bool | forwardStoredOnceStore (GlobalVariable *GV, const StoreInst *StoredOnceStore, function_ref< DominatorTree &(Function &)> LookupDomTree) |
| static bool | processInternalGlobal (GlobalVariable *GV, const GlobalStatus &GS, function_ref< TargetTransformInfo &(Function &)> GetTTI, function_ref< TargetLibraryInfo &(Function &)> GetTLI, function_ref< DominatorTree &(Function &)> LookupDomTree) |
| Analyze the specified global variable and optimize it if possible. | |
| static bool | processGlobal (GlobalValue &GV, function_ref< TargetTransformInfo &(Function &)> GetTTI, function_ref< TargetLibraryInfo &(Function &)> GetTLI, function_ref< DominatorTree &(Function &)> LookupDomTree) |
| Analyze the specified global variable and optimize it if possible. | |
| static void | ChangeCalleesToFastCall (Function *F) |
| Walk all of the direct calls of the specified function, changing them to FastCC. | |
| static AttributeList | StripAttr (LLVMContext &C, AttributeList Attrs, Attribute::AttrKind A) |
| static void | RemoveAttribute (Function *F, Attribute::AttrKind A) |
| static bool | hasChangeableCCImpl (Function *F) |
| Return true if this is a calling convention that we'd like to change. | |
| static bool | hasChangeableCC (Function *F, ChangeableCCCacheTy &ChangeableCCCache) |
| static bool | isColdCallSite (const IPOOptions &Opts, CallBase &CB, BlockFrequencyInfo &CallerBFI) |
| Return true if the block containing the call site has a BlockFrequency of less than -coldcc-rel-freq percent of the entry block. | |
| static bool | isValidCandidateForColdCC (const IPOOptions &Opts, Function &F, function_ref< BlockFrequencyInfo &(Function &)> GetBFI, function_ref< bool(Function &)> HasOnlyColdCalls) |
| static void | changeCallSitesToColdCC (Function *F) |
| static bool | hasOnlyColdCalls (const IPOOptions &Opts, Function &F, function_ref< BlockFrequencyInfo &(Function &)> GetBFI, ChangeableCCCacheTy &ChangeableCCCache) |
| static bool | hasMustTailCallers (Function *F) |
| static bool | hasInvokeCallers (Function *F) |
| static void | RemovePreallocated (Function *F) |
| static bool | OptimizeFunctions (Module &M, function_ref< TargetLibraryInfo &(Function &)> GetTLI, function_ref< TargetTransformInfo &(Function &)> GetTTI, function_ref< BlockFrequencyInfo &(Function &)> GetBFI, function_ref< DominatorTree &(Function &)> LookupDomTree, SmallPtrSetImpl< const Comdat * > &NotDiscardableComdats, function_ref< void(Function &F)> ChangedCFGCallback, function_ref< void(Function &F)> DeleteFnCallback) |
| static bool | OptimizeGlobalVars (Module &M, function_ref< TargetTransformInfo &(Function &)> GetTTI, function_ref< TargetLibraryInfo &(Function &)> GetTLI, function_ref< DominatorTree &(Function &)> LookupDomTree, SmallPtrSetImpl< const Comdat * > &NotDiscardableComdats) |
| static bool | EvaluateStaticConstructor (Function *F, const DataLayout &DL, TargetLibraryInfo *TLI) |
| Evaluate static constructors in the function, if we can. | |
| static int | compareNames (Constant *const *A, Constant *const *B) |
| static void | setUsedInitializer (GlobalVariable &V, const SmallPtrSetImpl< GlobalValue * > &Init) |
| static bool | hasUseOtherThanLLVMUsed (GlobalAlias &GA, const LLVMUsed &U) |
| static bool | mayHaveOtherReferences (GlobalValue &GV, const LLVMUsed &U) |
| static bool | hasUsesToReplace (GlobalAlias &GA, const LLVMUsed &U, bool &RenameTarget) |
| static bool | OptimizeGlobalAliases (Module &M, SmallPtrSetImpl< const Comdat * > &NotDiscardableComdats) |
| static Function * | FindAtExitLibFunc (Module &M, function_ref< TargetLibraryInfo &(Function &)> GetTLI, LibFunc Func) |
| static bool | IsEmptyAtExitFunction (const Function &Fn) |
| Returns whether the given function is an empty C++ destructor or atexit handler and can therefore be eliminated. | |
| static bool | OptimizeEmptyGlobalAtExitDtors (Function *CXAAtExitFn, bool isCXX) |
| static Function * | hasSideeffectFreeStaticResolution (GlobalIFunc &IF) |
| static bool | OptimizeStaticIFuncs (Module &M) |
| Find IFuncs that have resolvers that always point at the same statically known callee, and replace their callers with a direct call. | |
| static bool | DeleteDeadIFuncs (Module &M, SmallPtrSetImpl< const Comdat * > &NotDiscardableComdats) |
| static bool | collectVersions (Value *V, SmallVectorImpl< Function * > &Versions, function_ref< TargetTransformInfo &(Function &)> GetTTI) |
| static bool | OptimizeNonTrivialIFuncs (Module &M, function_ref< TargetTransformInfo &(Function &)> GetTTI) |
| static bool | optimizeGlobalsInModule (Module &M, const DataLayout &DL, function_ref< TargetLibraryInfo &(Function &)> GetTLI, function_ref< TargetTransformInfo &(Function &)> GetTTI, function_ref< BlockFrequencyInfo &(Function &)> GetBFI, function_ref< DominatorTree &(Function &)> LookupDomTree, function_ref< void(Function &F)> ChangedCFGCallback, function_ref< void(Function &F)> DeleteFnCallback) |
Macro Definition Documentation
◆ DEBUG_TYPE
| #define DEBUG_TYPE "globalopt" |
Definition at line 74 of file GlobalOpt.cpp.
Typedef Documentation
◆ ChangeableCCCacheTy
| using ChangeableCCCacheTy = SmallDenseMap<Function *, bool, 8> |
Definition at line 1368 of file GlobalOpt.cpp.
Function Documentation
◆ ChangeCalleesToFastCall()
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static |
Walk all of the direct calls of the specified function, changing them to FastCC.
Definition at line 1308 of file GlobalOpt.cpp.
References Call, llvm::dyn_cast(), F, and llvm::CallingConv::Fast.
Referenced by OptimizeFunctions().
◆ changeCallSitesToColdCC()
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Definition at line 1415 of file GlobalOpt.cpp.
References Call, llvm::CallingConv::Cold, llvm::dyn_cast(), and F.
Referenced by OptimizeFunctions().
◆ CleanupConstantGlobalUsers()
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static |
We just marked GV constant.
Loop over all users of the global, cleaning up the obvious ones. This is largely just a quick scan over the use list to clean up the easy and obvious cruft. This returns true if it made a change.
Definition at line 257 of file GlobalOpt.cpp.
References llvm::append_range(), Changed, llvm::ConstantFoldLoadFromConst(), llvm::ConstantFoldLoadFromUniformValue(), DL, llvm::dyn_cast(), llvm::SmallVectorTemplateCommon< T, typename >::empty(), GEP, llvm::GlobalVariable::getInitializer(), llvm::Value::getType(), llvm::getUnderlyingObject(), I, II, llvm::SmallPtrSetImpl< PtrType >::insert(), MI, llvm::Offset, llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::RecursivelyDeleteTriviallyDeadInstructionsPermissive(), llvm::Constant::removeDeadConstantUsers(), llvm::Value::stripAndAccumulateConstantOffsets(), and llvm::Value::users().
Referenced by OptimizeAwayTrappingUsesOfLoads(), and processInternalGlobal().
◆ CleanupPointerRootUsers()
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static |
This GV is a pointer root.
Loop over all users of the global and clean up any that obviously don't assign the global a value that isn't dynamically allocated.
Definition at line 179 of file GlobalOpt.cpp.
References llvm::append_range(), Changed, llvm::Dead, llvm::dyn_cast(), llvm::SmallVectorTemplateCommon< T, typename >::empty(), I, llvm::isa(), llvm::isAllocationFn(), llvm::GlobalVariable::isConstant(), IsSafeComputationToRemove(), llvm::SmallVectorImpl< T >::pop_back_val(), llvm::Constant::removeDeadConstantUsers(), llvm::Store, llvm::Value::users(), and V.
Referenced by OptimizeAwayTrappingUsesOfLoads(), and processInternalGlobal().
◆ collectSRATypes()
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static |
Look at all uses of the global and determine which (offset, type) pairs it can be split into.
Definition at line 336 of file GlobalOpt.cpp.
References C(), llvm::ConstantFoldLoadFromConst(), llvm::dbgs(), DL, llvm::dyn_cast(), llvm::SmallVectorTemplateCommon< T, typename >::empty(), GEP, llvm::GlobalVariable::getInitializer(), llvm::getLoadStorePointerOperand(), llvm::getLoadStoreType(), llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::isa(), llvm::isSafeToDestroyConstant(), LLVM_DEBUG, llvm::Offset, llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::try_emplace(), and V.
Referenced by SRAGlobal().
◆ collectVersions()
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static |
Definition at line 2133 of file GlobalOpt.cpp.
References collectVersions(), llvm::dyn_cast(), E(), F, I, llvm::SmallVectorTemplateBase< T, bool >::push_back(), and V.
Referenced by collectVersions(), and OptimizeNonTrivialIFuncs().
◆ compareNames()
Definition at line 1746 of file GlobalOpt.cpp.
References A(), B(), llvm::StringRef::compare(), llvm::Value::getName(), and llvm::Value::stripPointerCasts().
Referenced by setUsedInitializer().
◆ DeleteDeadIFuncs()
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static |
Definition at line 2118 of file GlobalOpt.cpp.
References Changed, deleteIfDead(), and llvm::make_early_inc_range().
Referenced by optimizeGlobalsInModule().
◆ deleteIfDead()
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static |
Definition at line 946 of file GlobalOpt.cpp.
References C(), llvm::SmallPtrSetImpl< PtrType >::count(), llvm::dbgs(), llvm::Dead, llvm::dyn_cast(), llvm::GlobalValue::eraseFromParent(), F, llvm::GlobalValue::getComdat(), llvm::GlobalValue::hasLocalLinkage(), llvm::GlobalValue::isDeclaration(), llvm::GlobalValue::isDiscardableIfUnused(), LLVM_DEBUG, llvm::Constant::removeDeadConstantUsers(), llvm::ReplaceableUses::SalvageDebugInfo(), and llvm::Value::use_empty().
Referenced by DeleteDeadIFuncs(), OptimizeFunctions(), OptimizeGlobalAliases(), and OptimizeGlobalVars().
◆ EvaluateStaticConstructor()
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static |
Evaluate static constructors in the function, if we can.
Return true if we can, false otherwise.
Definition at line 1718 of file GlobalOpt.cpp.
References llvm::dbgs(), DL, llvm::Evaluator::EvaluateFunction(), F, llvm::Evaluator::getInvariants(), llvm::Evaluator::getMutatedInitializers(), LLVM_DEBUG, and TLI.
Referenced by optimizeGlobalsInModule().
◆ FindAtExitLibFunc()
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Definition at line 1982 of file GlobalOpt.cpp.
References llvm::Function::begin(), llvm::Function::getFunction(), and TLI.
Referenced by optimizeGlobalsInModule().
◆ forwardStoredOnceStore()
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Definition at line 1046 of file GlobalOpt.cpp.
References llvm::dyn_cast(), llvm::SmallVectorTemplateCommon< T, typename >::empty(), F, llvm::Instruction::getFunction(), llvm::Value::getType(), llvm::StoreInst::getValueOperand(), llvm::isa(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), and llvm::Value::users().
Referenced by processInternalGlobal().
◆ hasChangeableCC()
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static |
Definition at line 1369 of file GlobalOpt.cpp.
References F, hasChangeableCCImpl(), and llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::try_emplace().
Referenced by hasOnlyColdCalls(), and OptimizeFunctions().
◆ hasChangeableCCImpl()
Return true if this is a calling convention that we'd like to change.
The idea here is that we don't want to mess with the convention if the user explicitly requested something with performance implications like coldcc, GHC, or anyregcc.
Definition at line 1335 of file GlobalOpt.cpp.
References llvm::CallingConv::C, CC, llvm::dyn_cast(), F, llvm::CallInst::isMustTailCall(), and llvm::CallingConv::X86_ThisCall.
Referenced by hasChangeableCC().
◆ hasInvokeCallers()
Definition at line 1467 of file GlobalOpt.cpp.
References F, and llvm::isa().
Referenced by OptimizeFunctions().
◆ hasMustTailCallers()
Definition at line 1458 of file GlobalOpt.cpp.
References llvm::cast(), F, and llvm::CallBase::isMustTailCall().
Referenced by OptimizeFunctions().
◆ hasOnlyColdCalls()
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Definition at line 1426 of file GlobalOpt.cpp.
References llvm::dyn_cast(), F, llvm::Function::getIntrinsicID(), hasChangeableCC(), llvm::GlobalValue::hasLocalLinkage(), I, isColdCallSite(), and llvm::Intrinsic::not_intrinsic.
Referenced by OptimizeFunctions().
◆ hasSideeffectFreeStaticResolution()
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Definition at line 2073 of file GlobalOpt.cpp.
References llvm::any_of(), llvm::dyn_cast(), llvm::GlobalIFunc::getResolverFunction(), llvm::BasicBlock::getTerminator(), I, and llvm::GlobalValue::isInterposable().
Referenced by OptimizeStaticIFuncs().
◆ hasUseOtherThanLLVMUsed()
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Definition at line 1849 of file GlobalOpt.cpp.
References assert(), llvm::Value::hasOneUse(), and llvm::Value::use_empty().
Referenced by hasUsesToReplace().
◆ hasUsesToReplace()
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Definition at line 1872 of file GlobalOpt.cpp.
References llvm::cast(), llvm::GlobalAlias::getAliasee(), hasUseOtherThanLLVMUsed(), llvm::GlobalValue::isWeakForLinker(), mayHaveOtherReferences(), and llvm::Constant::stripPointerCasts().
Referenced by OptimizeGlobalAliases().
◆ isColdCallSite()
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Return true if the block containing the call site has a BlockFrequency of less than -coldcc-rel-freq percent of the entry block.
Definition at line 1379 of file GlobalOpt.cpp.
References llvm::BlockFrequencyInfo::getBlockFreq(), llvm::CallBase::getCaller(), llvm::Function::getEntryBlock(), and llvm::ilist_detail::node_parent_access< NodeTy, ParentTy >::getParent().
Referenced by hasOnlyColdCalls(), and isValidCandidateForColdCC().
◆ IsEmptyAtExitFunction()
Returns whether the given function is an empty C++ destructor or atexit handler and can therefore be eliminated.
Note that we assume that other optimization passes have already simplified the code so we simply check for 'ret'.
Definition at line 2012 of file GlobalOpt.cpp.
References llvm::Function::getEntryBlock(), I, llvm::isa(), and llvm::GlobalValue::isDeclaration().
Referenced by OptimizeEmptyGlobalAtExitDtors().
◆ isLeakCheckerRoot()
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static |
Is this global variable possibly used by a leak checker as a root?
If so, we might not really want to eliminate the stores to it.
Definition at line 98 of file GlobalOpt.cpp.
References llvm::Type::ArrayTyID, llvm::cast(), llvm::StructType::elements(), llvm::Type::FixedVectorTyID, llvm::GlobalValue::getValueType(), llvm::GlobalValue::hasPrivateLinkage(), llvm::isa(), llvm::StructType::isOpaque(), llvm::isPointerTy(), llvm::Type::PointerTyID, llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::Type::ScalableVectorTyID, and llvm::Type::StructTyID.
Referenced by OptimizeAwayTrappingUsesOfLoads(), and processInternalGlobal().
◆ isPointerValueDeadOnEntryToFunction()
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Definition at line 977 of file GlobalOpt.cpp.
References assert(), DL, llvm::dyn_cast(), F, llvm::GlobalValue::getDataLayout(), llvm::Value::getType(), llvm::StoreInst::getValueOperand(), I, llvm::none_of(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::SmallVectorTemplateCommon< T, typename >::size(), and llvm::Value::users().
Referenced by processInternalGlobal().
◆ IsSafeComputationToRemove()
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Given a value that is stored to a global but never read, determine whether it's safe to remove the store and the chain of computation that feeds the store.
Definition at line 148 of file GlobalOpt.cpp.
References llvm::cast(), llvm::dyn_cast(), GEP, I, llvm::isa(), llvm::isAllocationFn(), and V.
Referenced by CleanupPointerRootUsers().
◆ isValidCandidateForColdCC()
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Definition at line 1394 of file GlobalOpt.cpp.
References llvm::dyn_cast(), F, llvm::CallBase::getCalledOperand(), llvm::ilist_detail::node_parent_access< NodeTy, ParentTy >::getParent(), and isColdCallSite().
Referenced by OptimizeFunctions().
◆ mayHaveOtherReferences()
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Definition at line 1865 of file GlobalOpt.cpp.
References llvm::GlobalValue::hasLocalLinkage().
Referenced by hasUsesToReplace(), and OptimizeGlobalAliases().
◆ OptimizeAwayTrappingUsesOfLoads()
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static |
The specified global has only one non-null value stored into it.
If there are uses of the loaded value that would trap if the loaded value is dynamically null, then we know that they cannot be reachable with a null optimize away the load.
Definition at line 701 of file GlobalOpt.cpp.
References assert(), Changed, CleanupConstantGlobalUsers(), CleanupPointerRootUsers(), llvm::dbgs(), DL, llvm::dyn_cast(), llvm::GlobalVariable::eraseFromParent(), llvm::isa(), isLeakCheckerRoot(), LLVM_DEBUG, llvm::make_early_inc_range(), OptimizeAwayTrappingUsesOfValue(), llvm::Value::use_empty(), and llvm::Value::users().
Referenced by optimizeOnceStoredGlobal().
◆ OptimizeAwayTrappingUsesOfValue()
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Definition at line 637 of file GlobalOpt.cpp.
References llvm::CallBase::arg_size(), C(), llvm::cast(), Changed, llvm::dyn_cast(), llvm::ConstantExpr::getAddrSpaceCast(), llvm::CallBase::getArgOperand(), llvm::CallBase::getCalledOperand(), llvm::ConstantExpr::getGetElementPtr(), llvm::Value::getType(), I, llvm::isa(), llvm::NullPointerIsDefined(), OptimizeAwayTrappingUsesOfValue(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::SmallVectorImpl< T >::reserve(), llvm::CallBase::setArgOperand(), llvm::CallBase::setCalledOperand(), llvm::SmallVectorTemplateCommon< T, typename >::size(), Users, and V.
Referenced by OptimizeAwayTrappingUsesOfLoads(), and OptimizeAwayTrappingUsesOfValue().
◆ OptimizeEmptyGlobalAtExitDtors()
Itanium C++ ABI p3.3.5:
After constructing a global (or local static) object, that will require destruction on exit, a termination function is registered as follows:
extern "C" int __cxa_atexit ( void (*f)(void *), void *p, void *d );
This registration, e.g. __cxa_atexit(f,p,d), is intended to cause the call f(p) when DSO d is unloaded, before all such termination calls registered before this one. It returns zero if registration is successful, nonzero on failure.
Definition at line 2028 of file GlobalOpt.cpp.
References Changed, llvm::dyn_cast(), llvm::Instruction::eraseFromParent(), llvm::CallBase::getArgOperand(), llvm::Constant::getNullValue(), llvm::Value::getType(), llvm::CallBase::isCallee(), IsEmptyAtExitFunction(), llvm::make_early_inc_range(), llvm::Value::replaceAllUsesWith(), llvm::Value::stripPointerCasts(), and llvm::Value::uses().
Referenced by optimizeGlobalsInModule().
◆ OptimizeFunctions()
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Definition at line 1552 of file GlobalOpt.cpp.
References ChangeCalleesToFastCall(), changeCallSitesToColdCC(), Changed, llvm::CallingConv::Cold, deleteIfDead(), llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::erase(), F, llvm::CallingConv::Fast, llvm::getIPOOptions(), hasChangeableCC(), hasInvokeCallers(), hasMustTailCallers(), hasOnlyColdCalls(), llvm::GlobalValue::InternalLinkage, isValidCandidateForColdCC(), llvm::make_early_inc_range(), processGlobal(), RemoveAttribute(), RemovePreallocated(), llvm::removeUnreachableBlocks(), and llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::try_emplace().
Referenced by optimizeGlobalsInModule().
◆ OptimizeGlobalAliases()
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Definition at line 1903 of file GlobalOpt.cpp.
References Changed, deleteIfDead(), llvm::dyn_cast(), llvm::GlobalValue::getLinkage(), hasUsesToReplace(), llvm::GlobalValue::InternalLinkage, llvm::GlobalValue::isDSOLocal(), llvm::GlobalValue::isImplicitDSOLocal(), llvm::GlobalValue::isInterposableLinkage(), llvm::make_early_inc_range(), mayHaveOtherReferences(), and llvm::Constant::stripPointerCasts().
Referenced by optimizeGlobalsInModule().
◆ optimizeGlobalsInModule()
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Definition at line 2380 of file GlobalOpt.cpp.
References C(), Changed, llvm::SmallPtrSetImplBase::clear(), DeleteDeadIFuncs(), DL, EvaluateStaticConstructor(), F, FindAtExitLibFunc(), llvm::GlobalValue::getComdat(), llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::GlobalValue::isDiscardableIfUnused(), OptimizeEmptyGlobalAtExitDtors(), OptimizeFunctions(), OptimizeGlobalAliases(), llvm::optimizeGlobalCtorsList(), OptimizeGlobalVars(), OptimizeNonTrivialIFuncs(), OptimizeStaticIFuncs(), and llvm::Value::use_empty().
Referenced by llvm::GlobalOptPass::run().
◆ OptimizeGlobalVars()
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Definition at line 1683 of file GlobalOpt.cpp.
References C(), Changed, llvm::ConstantFoldConstant(), deleteIfDead(), DL, llvm::GlobalValue::hasLocalLinkage(), llvm::Value::hasName(), llvm::GlobalValue::InternalLinkage, llvm::GlobalValue::isDeclaration(), llvm::make_early_inc_range(), processGlobal(), and llvm::GlobalValue::setLinkage().
Referenced by optimizeGlobalsInModule().
◆ OptimizeNonTrivialIFuncs()
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Definition at line 2176 of file GlobalOpt.cpp.
References llvm::all_of(), llvm::any_of(), Changed, collectVersions(), llvm::dbgs(), llvm::dyn_cast(), E(), llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::empty(), llvm::SmallVectorTemplateCommon< T, typename >::empty(), llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::find(), llvm::getIPOOptions(), llvm::BasicBlock::getTerminator(), I, llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::insert(), llvm::detail::DenseSetImpl< ValueT, MapTy >::insert(), llvm::APInt::isSubsetOf(), LHS, LLVM_DEBUG, llvm::SmallVectorTemplateBase< T, bool >::push_back(), RHS, llvm::CallBase::setCalledOperand(), llvm::ArrayRef< T >::size(), llvm::sort(), llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::try_emplace(), llvm::Value::users(), and V.
Referenced by optimizeGlobalsInModule().
◆ optimizeOnceStoredGlobal()
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Definition at line 758 of file GlobalOpt.cpp.
References DL, llvm::dyn_cast(), llvm::GlobalVariable::getInitializer(), llvm::Type::getPointerAddressSpace(), llvm::Value::getType(), llvm::Constant::isNullValue(), llvm::Type::isPointerTy(), llvm::NullPointerIsDefined(), and OptimizeAwayTrappingUsesOfLoads().
Referenced by processInternalGlobal().
◆ OptimizeStaticIFuncs()
Find IFuncs that have resolvers that always point at the same statically known callee, and replace their callers with a direct call.
Definition at line 2103 of file GlobalOpt.cpp.
References Changed, hasSideeffectFreeStaticResolution(), and llvm::none_of().
Referenced by optimizeGlobalsInModule().
◆ processGlobal()
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Analyze the specified global variable and optimize it if possible.
If we make a change, return true.
Definition at line 1261 of file GlobalOpt.cpp.
References llvm::GlobalStatus::analyzeGlobal(), Changed, llvm::dyn_cast(), llvm::Value::getName(), llvm::GlobalValue::getUnnamedAddr(), llvm::GlobalValue::Global, llvm::GlobalValue::hasAtLeastLocalUnnamedAddr(), llvm::GlobalValue::hasGlobalUnnamedAddr(), llvm::GlobalValue::hasLocalLinkage(), llvm::isa(), llvm::GlobalValue::Local, processInternalGlobal(), llvm::GlobalValue::setUnnamedAddr(), and llvm::StringRef::starts_with().
Referenced by OptimizeFunctions(), and OptimizeGlobalVars().
◆ processInternalGlobal()
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Analyze the specified global variable and optimize it if possible.
If we make a change, return true.
Definition at line 1082 of file GlobalOpt.cpp.
References assert(), Changed, CleanupConstantGlobalUsers(), CleanupPointerRootUsers(), llvm::dbgs(), DL, llvm::dyn_cast(), llvm::GlobalVariable::eraseFromParent(), forwardStoredOnceStore(), llvm::GlobalValue::getAddressSpace(), llvm::PointerType::getAddressSpace(), llvm::DebugLoc::getCompilerGenerated(), llvm::GlobalValue::getDataLayout(), llvm::GlobalVariable::getGlobalSize(), llvm::GlobalVariable::getInitializer(), llvm::GlobalValue::getLinkage(), llvm::Value::getName(), llvm::GlobalValue::getParent(), llvm::GlobalValue::getThreadLocalMode(), llvm::GlobalValue::getType(), llvm::Value::getType(), llvm::GlobalValue::getValueType(), llvm::GlobalStatus::InitializerStored, llvm::isa(), llvm::GlobalVariable::isConstant(), llvm::GlobalVariable::isExternallyInitialized(), isLeakCheckerRoot(), isPointerValueDeadOnEntryToFunction(), llvm::Type::isSingleValueType(), LLVM_DEBUG, llvm::NotAtomic, optimizeOnceStoredGlobal(), llvm::Value::replaceAllUsesWith(), llvm::GlobalVariable::setConstant(), llvm::Instruction::setDebugLoc(), llvm::GlobalVariable::setInitializer(), SRAGlobal(), llvm::GlobalStatus::StoredOnce, TryToShrinkGlobalToBoolean(), and llvm::Value::use_empty().
Referenced by processGlobal().
◆ RemoveAttribute()
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Definition at line 1323 of file GlobalOpt.cpp.
References A(), llvm::cast(), F, llvm::CallBase::getAttributes(), llvm::CallBase::setAttributes(), and StripAttr().
Referenced by OptimizeFunctions(), and RemovePreallocated().
◆ RemovePreallocated()
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Definition at line 1474 of file GlobalOpt.cpp.
References assert(), llvm::SmallVectorTemplateCommon< T, typename >::begin(), llvm::cast(), llvm::CallBase::Create(), llvm::SmallVectorTemplateCommon< T, typename >::end(), llvm::SmallVectorImpl< T >::erase(), F, llvm::CallBase::getArgOperand(), llvm::ilist_node_with_parent< NodeTy, ParentTy, Options >::getNextNode(), llvm::isa(), llvm::make_isa_range(), RemoveAttribute(), llvm::Value::takeName(), uint64_t, and llvm::Instruction::users().
Referenced by OptimizeFunctions().
◆ setUsedInitializer()
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Definition at line 1752 of file GlobalOpt.cpp.
References llvm::GlobalValue::AppendingLinkage, llvm::array_pod_sort(), llvm::SmallVectorTemplateCommon< T, typename >::begin(), llvm::cast(), compareNames(), llvm::SmallVectorTemplateCommon< T, typename >::end(), llvm::ArrayType::get(), llvm::ConstantArray::get(), llvm::PointerType::get(), llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(), llvm::GlobalValue::NotThreadLocal, llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::SmallVectorTemplateCommon< T, typename >::size(), and V.
◆ SRAGlobal()
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Perform scalar replacement of aggregates on the specified global variable.
This opens the door for other optimizations by exposing the behavior of the program in a more fine-grained way. We have determined that this transformation is safe already. We return the first global variable we insert so that the caller can reprocess it.
Definition at line 505 of file GlobalOpt.cpp.
References _, assert(), llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::begin(), llvm::cast(), collectSRATypes(), llvm::commonAlignment(), llvm::GlobalVariable::copyAttributesFrom(), llvm::count_if(), llvm::dbgs(), DL, llvm::dyn_cast(), llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::empty(), llvm::SmallVectorTemplateCommon< T, typename >::empty(), llvm::GlobalVariable::eraseFromParent(), llvm::GlobalValue::getAddressSpace(), llvm::GlobalVariable::getAlign(), llvm::GlobalVariable::getGlobalSize(), llvm::getLoadStorePointerOperand(), llvm::getLoadStoreType(), llvm::Value::getName(), llvm::getOrEnforceKnownAlignment(), llvm::GlobalValue::getParent(), llvm::GlobalValue::getThreadLocalMode(), llvm::GlobalValue::getValueType(), llvm::GlobalValue::hasLocalLinkage(), llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::insert(), llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::GlobalValue::InternalLinkage, llvm::isa(), llvm::isSafeToDestroyConstant(), LLVM_DEBUG, NumParts, llvm::Offset, llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::RecursivelyDeleteTriviallyDeadInstructions(), llvm::Constant::removeDeadConstantUsers(), llvm::GlobalVariable::setAlignment(), llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::size(), llvm::sort(), transferSRADebugInfo(), uint64_t, and V.
Referenced by processInternalGlobal().
◆ STATISTIC() [1/19]
| STATISTIC | ( | NumAliasesRemoved | , |
| "Number of global aliases eliminated" | ) |
◆ STATISTIC() [2/19]
| STATISTIC | ( | NumAliasesResolved | , |
| "Number of global aliases resolved" | ) |
◆ STATISTIC() [3/19]
| STATISTIC | ( | NumAtExitRemoved | , |
| "Number of atexit handlers removed" | ) |
◆ STATISTIC() [4/19]
| STATISTIC | ( | NumColdCC | , |
| "Number of functions marked coldcc" | ) |
◆ STATISTIC() [5/19]
| STATISTIC | ( | NumCtorsEvaluated | , |
| "Number of static ctors evaluated" | ) |
◆ STATISTIC() [6/19]
| STATISTIC | ( | NumCXXDtorsRemoved | , |
| "Number of global C++ destructors removed" | ) |
◆ STATISTIC() [7/19]
| STATISTIC | ( | NumDeleted | , |
| "Number of globals deleted" | ) |
◆ STATISTIC() [8/19]
| STATISTIC | ( | NumFastCallFns | , |
| "Number of functions converted to fastcc" | ) |
◆ STATISTIC() [9/19]
| STATISTIC | ( | NumGlobUses | , |
| "Number of global uses devirtualized" | ) |
◆ STATISTIC() [10/19]
| STATISTIC | ( | NumIFuncsDeleted | , |
| "Number of IFuncs removed" | ) |
◆ STATISTIC() [11/19]
| STATISTIC | ( | NumIFuncsResolved | , |
| "Number of statically resolved IFuncs" | ) |
◆ STATISTIC() [12/19]
| STATISTIC | ( | NumInternalFunc | , |
| "Number of internal functions" | ) |
◆ STATISTIC() [13/19]
| STATISTIC | ( | NumLocalized | , |
| "Number of globals localized" | ) |
◆ STATISTIC() [14/19]
| STATISTIC | ( | NumMarked | , |
| "Number of globals marked constant" | ) |
◆ STATISTIC() [15/19]
| STATISTIC | ( | NumNestRemoved | , |
| "Number of nest attributes removed" | ) |
◆ STATISTIC() [16/19]
| STATISTIC | ( | NumShrunkToBool | , |
| "Number of global vars shrunk to booleans" | ) |
◆ STATISTIC() [17/19]
| STATISTIC | ( | NumSRA | , |
| "Number of aggregate globals broken into scalars" | ) |
◆ STATISTIC() [18/19]
| STATISTIC | ( | NumSubstitute | , |
| "Number of globals with initializers stored into them" | ) |
◆ STATISTIC() [19/19]
| STATISTIC | ( | NumUnnamed | , |
| "Number of globals marked unnamed_addr" | ) |
◆ StripAttr()
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Definition at line 1315 of file GlobalOpt.cpp.
Referenced by RemoveAttribute().
◆ transferSRADebugInfo()
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Copy over the debug info for a variable to its SRA replacements.
Definition at line 425 of file GlobalOpt.cpp.
References llvm::GlobalVariable::addDebugInfo(), llvm::DIExpression::createFragmentExpression(), E(), llvm::DIExpression::extractIfOffset(), llvm::MDNode::get(), llvm::MDNode::getContext(), llvm::GlobalVariable::getDebugInfo(), llvm::DIType::getSizeInBits(), llvm::DIVariable::getType(), and uint64_t.
Referenced by SRAGlobal().
◆ TryToShrinkGlobalToBoolean()
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At this point, we have learned that the only two values ever stored into GV are its initializer and OtherVal.
See if we can shrink the global into a boolean and select between the two values whenever it is used. This exposes the values to other scalar optimizations.
Definition at line 785 of file GlobalOpt.cpp.
References AbstractManglingParser< Derived, Alloc >::Ops, llvm::GlobalVariable::addDebugInfo(), assert(), llvm::cast(), llvm::GlobalVariable::copyAttributesFrom(), llvm::SelectInst::Create(), llvm::dbgs(), DEBUG_TYPE, DL, llvm::dyn_cast(), E(), llvm::GlobalVariable::eraseFromParent(), llvm::Instruction::eraseFromParent(), llvm::MDNode::get(), llvm::PointerType::getAddressSpace(), llvm::Value::getContext(), llvm::GlobalValue::getDataLayout(), llvm::GlobalVariable::getDebugInfo(), llvm::Instruction::getDebugLoc(), llvm::ConstantInt::getFalse(), llvm::GlobalVariable::getGlobalSize(), llvm::GlobalVariable::getInitializer(), llvm::Type::getInt1Ty(), llvm::ilist_node_impl< OptionsT >::getIterator(), llvm::getLoadStoreType(), llvm::Value::getName(), llvm::User::getOperand(), llvm::LoadInst::getOrdering(), llvm::GlobalValue::getParent(), llvm::LoadInst::getSyncScopeID(), llvm::GlobalValue::getThreadLocalMode(), llvm::GlobalValue::getType(), llvm::Value::getType(), llvm::GlobalValue::getValueType(), llvm::Module::insertGlobalVariable(), llvm::GlobalValue::InternalLinkage, llvm::isa(), llvm::Type::isFloatingPointTy(), llvm::Constant::isNullValue(), llvm::Type::isPointerTy(), llvm::Type::isVectorTy(), LLVM_DEBUG, llvm::DIExpression::prependOpcodes(), llvm::Value::replaceAllUsesWith(), llvm::Instruction::setDebugLoc(), llvm::setExplicitlyUnknownBranchWeightsIfProfiled(), llvm::Value::takeName(), uint64_t, llvm::Value::use_empty(), llvm::Value::user_back(), and llvm::Value::users().
Referenced by processInternalGlobal().
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