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LLVM
3.7.0
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#include "llvm/Transforms/IPO.h"#include "llvm/ADT/DenseMap.h"#include "llvm/ADT/STLExtras.h"#include "llvm/ADT/SmallPtrSet.h"#include "llvm/ADT/SmallSet.h"#include "llvm/ADT/SmallVector.h"#include "llvm/ADT/Statistic.h"#include "llvm/Analysis/ConstantFolding.h"#include "llvm/Analysis/MemoryBuiltins.h"#include "llvm/Analysis/TargetLibraryInfo.h"#include "llvm/IR/CallSite.h"#include "llvm/IR/CallingConv.h"#include "llvm/IR/Constants.h"#include "llvm/IR/DataLayout.h"#include "llvm/IR/DerivedTypes.h"#include "llvm/IR/GetElementPtrTypeIterator.h"#include "llvm/IR/Instructions.h"#include "llvm/IR/IntrinsicInst.h"#include "llvm/IR/Module.h"#include "llvm/IR/Operator.h"#include "llvm/IR/ValueHandle.h"#include "llvm/Pass.h"#include "llvm/Support/Debug.h"#include "llvm/Support/ErrorHandling.h"#include "llvm/Support/MathExtras.h"#include "llvm/Support/raw_ostream.h"#include "llvm/Transforms/Utils/CtorUtils.h"#include "llvm/Transforms/Utils/GlobalStatus.h"#include "llvm/Transforms/Utils/ModuleUtils.h"#include <algorithm>#include <deque>Go to the source code of this file.
Macros | |
| #define | DEBUG_TYPE "globalopt" |
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 (NumHeapSRA,"Number of heap objects SRA'd") | |
| STATISTIC (NumSubstitute,"Number of globals with initializers stored into them") | |
| STATISTIC (NumDeleted,"Number of globals deleted") | |
| STATISTIC (NumFnDeleted,"Number of functions 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") | |
| INITIALIZE_PASS_BEGIN (GlobalOpt,"globalopt","Global Variable Optimizer", false, false) INITIALIZE_PASS_END(GlobalOpt | |
| static bool | isLeakCheckerRoot (GlobalVariable *GV) |
| isLeakCheckerRoot - 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. More... | |
| static bool | IsSafeComputationToRemove (Value *V, const TargetLibraryInfo *TLI) |
| 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. More... | |
| static bool | CleanupPointerRootUsers (GlobalVariable *GV, const TargetLibraryInfo *TLI) |
| CleanupPointerRootUsers - This GV is a pointer root. More... | |
| static bool | CleanupConstantGlobalUsers (Value *V, Constant *Init, const DataLayout &DL, TargetLibraryInfo *TLI) |
| CleanupConstantGlobalUsers - We just marked GV constant. More... | |
| static bool | isSafeSROAElementUse (Value *V) |
| isSafeSROAElementUse - Return true if the specified instruction is a safe user of a derived expression from a global that we want to SROA. More... | |
| static bool | IsUserOfGlobalSafeForSRA (User *U, GlobalValue *GV) |
| IsUserOfGlobalSafeForSRA - U is a direct user of the specified global value. More... | |
| static bool | GlobalUsersSafeToSRA (GlobalValue *GV) |
| GlobalUsersSafeToSRA - Look at all uses of the global and decide whether it is safe for us to perform this transformation. More... | |
| static GlobalVariable * | SRAGlobal (GlobalVariable *GV, const DataLayout &DL) |
| SRAGlobal - Perform scalar replacement of aggregates on the specified global variable. More... | |
| static bool | AllUsesOfValueWillTrapIfNull (const Value *V, SmallPtrSetImpl< const PHINode * > &PHIs) |
| AllUsesOfValueWillTrapIfNull - Return true if all users of the specified value will trap if the value is dynamically null. More... | |
| static bool | AllUsesOfLoadedValueWillTrapIfNull (const GlobalVariable *GV) |
| AllUsesOfLoadedValueWillTrapIfNull - Return true if all uses of any loads from GV will trap if the loaded value is null. More... | |
| static bool | OptimizeAwayTrappingUsesOfValue (Value *V, Constant *NewV) |
| static bool | OptimizeAwayTrappingUsesOfLoads (GlobalVariable *GV, Constant *LV, const DataLayout &DL, TargetLibraryInfo *TLI) |
| OptimizeAwayTrappingUsesOfLoads - The specified global has only one non-null value stored into it. More... | |
| static void | ConstantPropUsersOf (Value *V, const DataLayout &DL, TargetLibraryInfo *TLI) |
| ConstantPropUsersOf - Walk the use list of V, constant folding all of the instructions that are foldable. More... | |
| static GlobalVariable * | OptimizeGlobalAddressOfMalloc (GlobalVariable *GV, CallInst *CI, Type *AllocTy, ConstantInt *NElements, const DataLayout &DL, TargetLibraryInfo *TLI) |
| OptimizeGlobalAddressOfMalloc - This function takes the specified global variable, and transforms the program as if it always contained the result of the specified malloc. More... | |
| static bool | ValueIsOnlyUsedLocallyOrStoredToOneGlobal (const Instruction *V, const GlobalVariable *GV, SmallPtrSetImpl< const PHINode * > &PHIs) |
| ValueIsOnlyUsedLocallyOrStoredToOneGlobal - Scan the use-list of V checking to make sure that there are no complex uses of V. More... | |
| static void | ReplaceUsesOfMallocWithGlobal (Instruction *Alloc, GlobalVariable *GV) |
| ReplaceUsesOfMallocWithGlobal - The Alloc pointer is stored into GV somewhere. More... | |
| static bool | LoadUsesSimpleEnoughForHeapSRA (const Value *V, SmallPtrSetImpl< const PHINode * > &LoadUsingPHIs, SmallPtrSetImpl< const PHINode * > &LoadUsingPHIsPerLoad) |
| LoadUsesSimpleEnoughForHeapSRA - Verify that all uses of V (a load, or a phi of a load) are simple enough to perform heap SRA on. More... | |
| static bool | AllGlobalLoadUsesSimpleEnoughForHeapSRA (const GlobalVariable *GV, Instruction *StoredVal) |
| AllGlobalLoadUsesSimpleEnoughForHeapSRA - If all users of values loaded from GV are simple enough to perform HeapSRA, return true. More... | |
| static Value * | GetHeapSROAValue (Value *V, unsigned FieldNo, DenseMap< Value *, std::vector< Value * > > &InsertedScalarizedValues, std::vector< std::pair< PHINode *, unsigned > > &PHIsToRewrite) |
| static void | RewriteHeapSROALoadUser (Instruction *LoadUser, DenseMap< Value *, std::vector< Value * > > &InsertedScalarizedValues, std::vector< std::pair< PHINode *, unsigned > > &PHIsToRewrite) |
| RewriteHeapSROALoadUser - Given a load instruction and a value derived from the load, rewrite the derived value to use the HeapSRoA'd load. More... | |
| static void | RewriteUsesOfLoadForHeapSRoA (LoadInst *Load, DenseMap< Value *, std::vector< Value * > > &InsertedScalarizedValues, std::vector< std::pair< PHINode *, unsigned > > &PHIsToRewrite) |
| RewriteUsesOfLoadForHeapSRoA - We are performing Heap SRoA on a global. More... | |
| static GlobalVariable * | PerformHeapAllocSRoA (GlobalVariable *GV, CallInst *CI, Value *NElems, const DataLayout &DL, const TargetLibraryInfo *TLI) |
| PerformHeapAllocSRoA - CI is an allocation of an array of structures. More... | |
| static bool | TryToOptimizeStoreOfMallocToGlobal (GlobalVariable *GV, CallInst *CI, Type *AllocTy, AtomicOrdering Ordering, Module::global_iterator &GVI, const DataLayout &DL, TargetLibraryInfo *TLI) |
| TryToOptimizeStoreOfMallocToGlobal - This function is called when we see a pointer global variable with a single value stored it that is a malloc or cast of malloc. More... | |
| static bool | OptimizeOnceStoredGlobal (GlobalVariable *GV, Value *StoredOnceVal, AtomicOrdering Ordering, Module::global_iterator &GVI, const DataLayout &DL, TargetLibraryInfo *TLI) |
| static bool | TryToShrinkGlobalToBoolean (GlobalVariable *GV, Constant *OtherVal) |
| TryToShrinkGlobalToBoolean - At this point, we have learned that the only two values ever stored into GV are its initializer and OtherVal. More... | |
| static void | ChangeCalleesToFastCall (Function *F) |
| ChangeCalleesToFastCall - Walk all of the direct calls of the specified function, changing them to FastCC. More... | |
| static AttributeSet | StripNest (LLVMContext &C, const AttributeSet &Attrs) |
| static void | RemoveNestAttribute (Function *F) |
| static bool | isProfitableToMakeFastCC (Function *F) |
| Return true if this is a calling convention that we'd like to change. More... | |
| static bool | isSimpleEnoughValueToCommit (Constant *C, SmallPtrSetImpl< Constant * > &SimpleConstants, const DataLayout &DL) |
| static bool | isSimpleEnoughValueToCommitHelper (Constant *C, SmallPtrSetImpl< Constant * > &SimpleConstants, const DataLayout &DL) |
| isSimpleEnoughValueToCommit - Return true if the specified constant can be handled by the code generator. More... | |
| static bool | isSimpleEnoughPointerToCommit (Constant *C) |
| isSimpleEnoughPointerToCommit - Return true if this constant is simple enough for us to understand. More... | |
| static Constant * | EvaluateStoreInto (Constant *Init, Constant *Val, ConstantExpr *Addr, unsigned OpNo) |
| EvaluateStoreInto - Evaluate a piece of a constantexpr store into a global initializer. More... | |
| static void | CommitValueTo (Constant *Val, Constant *Addr) |
| CommitValueTo - We have decided that Addr (which satisfies the predicate isSimpleEnoughPointerToCommit) should get Val as its value. More... | |
| static bool | EvaluateStaticConstructor (Function *F, const DataLayout &DL, const TargetLibraryInfo *TLI) |
| EvaluateStaticConstructor - Evaluate static constructors in the function, if we can. More... | |
| static int | compareNames (Constant *const *A, Constant *const *B) |
| static void | setUsedInitializer (GlobalVariable &V, const SmallPtrSet< GlobalValue *, 8 > &Init) |
| static bool | hasUseOtherThanLLVMUsed (GlobalAlias &GA, const LLVMUsed &U) |
| static bool | hasMoreThanOneUseOtherThanLLVMUsed (GlobalValue &V, const LLVMUsed &U) |
| static bool | mayHaveOtherReferences (GlobalAlias &GA, const LLVMUsed &U) |
| static bool | hasUsesToReplace (GlobalAlias &GA, const LLVMUsed &U, bool &RenameTarget) |
| static Function * | FindCXAAtExit (Module &M, TargetLibraryInfo *TLI) |
| static bool | cxxDtorIsEmpty (const Function &Fn, SmallPtrSet< const Function *, 8 > &CalledFunctions) |
| cxxDtorIsEmpty - Returns whether the given function is an empty C++ destructor and can therefore be eliminated. More... | |
Variables | |
| globalopt | |
| Global Variable | Optimizer |
| Global Variable | false |
| #define DEBUG_TYPE "globalopt" |
Definition at line 49 of file GlobalOpt.cpp.
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AllGlobalLoadUsesSimpleEnoughForHeapSRA - If all users of values loaded from GV are simple enough to perform HeapSRA, return true.
Definition at line 1101 of file GlobalOpt.cpp.
References llvm::SmallPtrSetImplBase::clear(), LoadUsesSimpleEnoughForHeapSRA(), op, and llvm::Value::users().
Referenced by TryToOptimizeStoreOfMallocToGlobal().
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AllUsesOfLoadedValueWillTrapIfNull - Return true if all uses of any loads from GV will trap if the loaded value is null.
Note that this also permits comparisons of the loaded value against null, as a special case.
Definition at line 659 of file GlobalOpt.cpp.
References AllUsesOfValueWillTrapIfNull(), and llvm::Value::users().
Referenced by TryToOptimizeStoreOfMallocToGlobal().
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AllUsesOfValueWillTrapIfNull - Return true if all users of the specified value will trap if the value is dynamically null.
PHIs keeps track of any phi nodes we've seen to avoid reprocessing them.
Definition at line 616 of file GlobalOpt.cpp.
References llvm::SmallPtrSetImpl< PtrType >::insert(), SI, and llvm::Value::users().
Referenced by AllUsesOfLoadedValueWillTrapIfNull().
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ChangeCalleesToFastCall - Walk all of the direct calls of the specified function, changing them to FastCC.
Definition at line 1855 of file GlobalOpt.cpp.
References llvm::CS, llvm::CallingConv::Fast, llvm::CallSiteBase< FunTy, BBTy, ValTy, UserTy, InstrTy, CallTy, InvokeTy, IterTy >::setCallingConv(), and llvm::Value::users().
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CleanupConstantGlobalUsers - 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 270 of file GlobalOpt.cpp.
References llvm::ConstantFoldInstruction(), llvm::ConstantFoldLoadThroughGEPConstantExpr(), GEP, llvm::Constant::getNullValue(), llvm::ConstantExpr::getOpcode(), llvm::isSafeToDestroyConstant(), llvm::AArch64CC::MI, llvm::Value::replaceAllUsesWith(), SI, llvm::Value::user_begin(), and llvm::Value::user_end().
Referenced by OptimizeAwayTrappingUsesOfLoads().
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CleanupPointerRootUsers - 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 183 of file GlobalOpt.cpp.
References llvm::SmallVectorImpl< T >::clear(), llvm::RegState::Dead, llvm::dyn_cast(), llvm::Instruction::eraseFromParent(), llvm::User::getOperand(), I, llvm::isAllocationFn(), llvm::GlobalVariable::isConstant(), IsSafeComputationToRemove(), llvm::isSafeToDestroyConstant(), llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), SI, llvm::SmallVectorTemplateCommon< T >::size(), llvm::Value::user_begin(), and llvm::Value::user_end().
Referenced by OptimizeAwayTrappingUsesOfLoads().
CommitValueTo - We have decided that Addr (which satisfies the predicate isSimpleEnoughPointerToCommit) should get Val as its value.
Make it happen.
Definition at line 2149 of file GlobalOpt.cpp.
References EvaluateStoreInto(), llvm::User::getOperand(), llvm::GlobalVariable::hasInitializer(), and llvm::GlobalVariable::setInitializer().
Referenced by EvaluateStaticConstructor().
Definition at line 2710 of file GlobalOpt.cpp.
Referenced by setUsedInitializer().
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ConstantPropUsersOf - Walk the use list of V, constant folding all of the instructions that are foldable.
Definition at line 806 of file GlobalOpt.cpp.
References llvm::ConstantFoldInstruction(), I, llvm::Value::user_begin(), and llvm::Value::user_end().
Referenced by OptimizeGlobalAddressOfMalloc().
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cxxDtorIsEmpty - Returns whether the given function is an empty C++ destructor and can therefore be eliminated.
Note that we assume that other optimization passes have already simplified the code so we only look for a function with a single basic block, where the only allowed instructions are 'ret', 'call' to an empty C++ dtor and other side-effect free instructions.
Definition at line 2945 of file GlobalOpt.cpp.
References llvm::BasicBlock::begin(), llvm::Function::begin(), llvm::BasicBlock::end(), llvm::Function::end(), llvm::Function::getEntryBlock(), I, llvm::SmallPtrSetImpl< PtrType >::insert(), and llvm::GlobalValue::isDeclaration().
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EvaluateStaticConstructor - Evaluate static constructors in the function, if we can.
Return true if we can, false otherwise.
Definition at line 2684 of file GlobalOpt.cpp.
References CommitValueTo(), llvm::dbgs(), DEBUG, llvm::Eval(), Evaluator, llvm::Value::getName(), I, and llvm::GlobalVariable::setConstant().
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EvaluateStoreInto - Evaluate a piece of a constantexpr store into a global initializer.
This returns 'Init' modified to reflect 'Val' stored into it. At this point, the GEP operands of Addr [0, OpNo) have been stepped into.
Definition at line 2101 of file GlobalOpt.cpp.
References llvm::ConstantArray::get(), llvm::ConstantStruct::get(), llvm::ConstantVector::get(), llvm::Constant::getAggregateElement(), llvm::User::getNumOperands(), llvm::User::getOperand(), llvm::Value::getType(), llvm::Type::getVectorNumElements(), llvm::ConstantInt::getZExtValue(), llvm::Type::isArrayTy(), and llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back().
Referenced by CommitValueTo().
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Definition at line 2916 of file GlobalOpt.cpp.
References llvm::Module::getFunction(), llvm::Function::getFunctionType(), llvm::TargetLibraryInfo::getName(), llvm::FunctionType::getNumParams(), llvm::FunctionType::getParamType(), llvm::FunctionType::getReturnType(), llvm::TargetLibraryInfo::has(), llvm::Type::isIntegerTy(), and llvm::Type::isPointerTy().
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Definition at line 1147 of file GlobalOpt.cpp.
References llvm::PHINode::Create(), llvm::PointerType::get(), llvm::Value::getName(), llvm::PHINode::getNumIncomingValues(), llvm::Value::getType(), and llvm::AArch64DB::ST.
Referenced by PerformHeapAllocSRoA(), and RewriteHeapSROALoadUser().
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GlobalUsersSafeToSRA - Look at all uses of the global and decide whether it is safe for us to perform this transformation.
Definition at line 458 of file GlobalOpt.cpp.
References IsUserOfGlobalSafeForSRA(), and llvm::Value::users().
Referenced by SRAGlobal().
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Definition at line 2805 of file GlobalOpt.cpp.
References llvm::Value::hasNUsesOrMore(), and N.
Referenced by hasUsesToReplace().
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Definition at line 2789 of file GlobalOpt.cpp.
References llvm::Value::hasOneUse(), and llvm::Value::use_empty().
Referenced by hasUsesToReplace().
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Definition at line 2823 of file GlobalOpt.cpp.
References llvm::GlobalAlias::getAliasee(), llvm::GlobalValue::hasLocalLinkage(), hasMoreThanOneUseOtherThanLLVMUsed(), hasUseOtherThanLLVMUsed(), mayHaveOtherReferences(), llvm::MipsISD::Ret, and llvm::Constant::stripPointerCasts().
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isLeakCheckerRoot - 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 105 of file GlobalOpt.cpp.
References llvm::Type::ArrayTyID, llvm::StructType::element_begin(), llvm::StructType::element_end(), llvm::SmallVectorBase::empty(), llvm::SequentialType::getElementType(), llvm::GlobalValue::getType(), llvm::Type::getTypeID(), llvm::GlobalValue::hasPrivateLinkage(), I, llvm::StructType::isOpaque(), llvm::Type::PointerTyID, llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), llvm::Type::StructTyID, and llvm::Type::VectorTyID.
Referenced by OptimizeAwayTrappingUsesOfLoads().
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 1891 of file GlobalOpt.cpp.
References llvm::CallingConv::C, llvm::Function::getCallingConv(), and llvm::CallingConv::X86_ThisCall.
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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 153 of file GlobalOpt.cpp.
References GEP, llvm::User::getNumOperands(), llvm::User::getOperand(), llvm::Value::hasOneUse(), I, llvm::isAllocationFn(), and llvm::Instruction::mayHaveSideEffects().
Referenced by CleanupPointerRootUsers().
isSafeSROAElementUse - Return true if the specified instruction is a safe user of a derived expression from a global that we want to SROA.
Definition at line 358 of file GlobalOpt.cpp.
References llvm::dyn_cast(), llvm::User::getNumOperands(), llvm::User::getOperand(), I, llvm::isSafeToDestroyConstant(), SI, and llvm::Value::users().
Referenced by IsUserOfGlobalSafeForSRA().
isSimpleEnoughPointerToCommit - Return true if this constant is simple enough for us to understand.
In particular, if it is a cast to anything other than from one pointer type to another pointer type, we punt. We basically just support direct accesses to globals and GEP's of globals. This should be kept up to date with CommitValueTo.
Definition at line 2052 of file GlobalOpt.cpp.
References llvm::ConstantFoldLoadThroughGEPConstantExpr(), llvm::dyn_cast(), llvm::GlobalVariable::getInitializer(), llvm::Value::getType(), llvm::GlobalVariable::hasUniqueInitializer(), and llvm::ConstantInt::isZero().
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Definition at line 2036 of file GlobalOpt.cpp.
References llvm::SmallPtrSetImpl< PtrType >::insert(), and isSimpleEnoughValueToCommitHelper().
Referenced by isSimpleEnoughValueToCommitHelper().
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isSimpleEnoughValueToCommit - Return true if the specified constant can be handled by the code generator.
We don't want to generate something like: void *X = &X/42; because the code generator doesn't have a relocation that can handle that.
This function should be called if C was not found (but just got inserted) in SimpleConstants to avoid having to rescan the same constants all the time.
Definition at line 1980 of file GlobalOpt.cpp.
References llvm::User::getNumOperands(), llvm::ConstantExpr::getOpcode(), llvm::User::getOperand(), llvm::Value::getType(), llvm::DataLayout::getTypeSizeInBits(), llvm::GlobalValue::hasDLLImportStorageClass(), isSimpleEnoughValueToCommit(), llvm::GlobalValue::isThreadLocal(), and llvm::User::operands().
Referenced by isSimpleEnoughValueToCommit().
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IsUserOfGlobalSafeForSRA - U is a direct user of the specified global value.
Look at it and its uses and decide whether it is safe to SROA this global.
Definition at line 391 of file GlobalOpt.cpp.
References llvm::dyn_cast(), llvm::gep_type_begin(), llvm::gep_type_end(), llvm::User::getNumOperands(), llvm::generic_gep_type_iterator< ItTy >::getOperand(), llvm::User::getOperand(), llvm::ConstantInt::getZExtValue(), isSafeSROAElementUse(), and llvm::Value::users().
Referenced by GlobalUsersSafeToSRA().
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LoadUsesSimpleEnoughForHeapSRA - Verify that all uses of V (a load, or a phi of a load) are simple enough to perform heap SRA on.
This permits GEP's that index through the array and struct field, icmps of null, and PHIs.
Definition at line 1049 of file GlobalOpt.cpp.
References llvm::SmallPtrSetImpl< PtrType >::insert(), and llvm::Value::users().
Referenced by AllGlobalLoadUsesSimpleEnoughForHeapSRA().
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Definition at line 2816 of file GlobalOpt.cpp.
References llvm::GlobalValue::hasLocalLinkage().
Referenced by hasUsesToReplace().
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OptimizeAwayTrappingUsesOfLoads - 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 742 of file GlobalOpt.cpp.
References CleanupConstantGlobalUsers(), CleanupPointerRootUsers(), llvm::dbgs(), DEBUG, llvm::GlobalVariable::eraseFromParent(), llvm::User::getOperand(), isLeakCheckerRoot(), OptimizeAwayTrappingUsesOfValue(), llvm::Value::use_empty(), llvm::Value::user_begin(), and llvm::Value::user_end().
Referenced by OptimizeOnceStoredGlobal().
Definition at line 675 of file GlobalOpt.cpp.
References llvm::CallSiteBase< FunTy, BBTy, ValTy, UserTy, InstrTy, CallTy, InvokeTy, IterTy >::arg_size(), llvm::CS, llvm::CallSiteBase< FunTy, BBTy, ValTy, UserTy, InstrTy, CallTy, InvokeTy, IterTy >::getArgument(), llvm::CallSiteBase< FunTy, BBTy, ValTy, UserTy, InstrTy, CallTy, InvokeTy, IterTy >::getCalledValue(), llvm::ConstantExpr::getCast(), llvm::ConstantExpr::getGetElementPtr(), llvm::Value::getType(), I, llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), llvm::SmallVectorImpl< T >::reserve(), llvm::CallSiteBase< FunTy, BBTy, ValTy, UserTy, InstrTy, CallTy, InvokeTy, IterTy >::setArgument(), llvm::CallSiteBase< FunTy, BBTy, ValTy, UserTy, InstrTy, CallTy, InvokeTy, IterTy >::setCalledFunction(), SI, llvm::SmallVectorTemplateCommon< T >::size(), llvm::Value::user_begin(), and llvm::Value::user_end().
Referenced by OptimizeAwayTrappingUsesOfLoads().
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OptimizeGlobalAddressOfMalloc - This function takes the specified global variable, and transforms the program as if it always contained the result of the specified malloc.
Because it is always the result of the specified malloc, there is no reason to actually DO the malloc. Instead, turn the malloc into a global, and any loads of GV as uses of the new global.
Definition at line 827 of file GlobalOpt.cpp.
References ConstantPropUsersOf(), llvm::BinaryOperator::CreateNot(), DEBUG, llvm::dyn_cast(), llvm::Instruction::eraseFromParent(), llvm::GlobalVariable::eraseFromParent(), llvm::errs(), llvm::ArrayType::get(), llvm::UndefValue::get(), llvm::ConstantExpr::getBitCast(), llvm::Value::getContext(), llvm::SequentialType::getElementType(), llvm::ConstantInt::getFalse(), llvm::Module::getGlobalList(), llvm::Type::getInt1Ty(), llvm::Value::getName(), llvm::LoadInst::getOrdering(), llvm::GlobalValue::getParent(), llvm::CmpInst::getPredicate(), llvm::LoadInst::getSynchScope(), llvm::GlobalValue::getThreadLocalMode(), llvm::ConstantInt::getTrue(), llvm::GlobalValue::getType(), llvm::Value::getType(), llvm::Use::getUser(), llvm::ConstantInt::getZExtValue(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_SGE, llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_SLE, llvm::CmpInst::ICMP_SLT, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULE, llvm::CmpInst::ICMP_ULT, llvm::iplist< NodeTy, Traits >::insert(), llvm::GlobalValue::InternalLinkage, llvm::LoadInst::isUnordered(), llvm_unreachable, llvm::Value::replaceAllUsesWith(), llvm::User::replaceUsesOfWith(), SI, llvm::Value::use_begin(), llvm::Value::use_empty(), llvm::Instruction::user_back(), and llvm::Value::user_back().
Referenced by TryToOptimizeStoreOfMallocToGlobal().
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Definition at line 1557 of file GlobalOpt.cpp.
References llvm::extractMallocCall(), llvm::ConstantExpr::getBitCast(), llvm::GlobalVariable::getInitializer(), llvm::getMallocAllocatedType(), llvm::Value::getType(), llvm::Constant::isNullValue(), llvm::Type::isPointerTy(), OptimizeAwayTrappingUsesOfLoads(), llvm::Value::stripPointerCasts(), and TryToOptimizeStoreOfMallocToGlobal().
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PerformHeapAllocSRoA - CI is an allocation of an array of structures.
Break it up into multiple allocations of arrays of the fields.
InsertedScalarizedLoads - As we process loads, if we can't immediately update all uses of the load, keep track of what scalarized loads are inserted for a given load.
Definition at line 1271 of file GlobalOpt.cpp.
References llvm::PHINode::addIncoming(), llvm::DenseMapBase< DenseMap< KeyT, ValueT, KeyInfoT, BucketT >, KeyT, ValueT, KeyInfoT, BucketT >::begin(), llvm::BasicBlock::Create(), llvm::BranchInst::Create(), llvm::CallInst::CreateFree(), llvm::CallInst::CreateMalloc(), llvm::dbgs(), DEBUG, llvm::DenseMapBase< DenseMap< KeyT, ValueT, KeyInfoT, BucketT >, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::Instruction::eraseFromParent(), llvm::GlobalVariable::eraseFromParent(), llvm::ConstantInt::get(), llvm::PointerType::get(), llvm::CallInst::getArgOperand(), llvm::BasicBlock::getContext(), llvm::Value::getContext(), llvm::StructType::getElementType(), llvm::SequentialType::getElementType(), GetHeapSROAValue(), llvm::PHINode::getIncomingBlock(), llvm::PHINode::getIncomingValue(), llvm::DataLayout::getIntPtrType(), llvm::getMallocAllocatedType(), llvm::Value::getName(), llvm::Constant::getNullValue(), llvm::StructType::getNumElements(), llvm::PHINode::getNumIncomingValues(), llvm::User::getOperand(), llvm::Instruction::getParent(), llvm::BasicBlock::getParent(), llvm::GlobalValue::getParent(), llvm::Type::getPointerAddressSpace(), llvm::StructLayout::getSizeInBytes(), llvm::DataLayout::getStructLayout(), llvm::BasicBlock::getTerminator(), llvm::GlobalValue::getThreadLocalMode(), llvm::Intrinsic::getType(), llvm::GlobalValue::getType(), llvm::Value::getType(), llvm::DataLayout::getTypeAllocSize(), I, llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_SLT, llvm::GlobalValue::InternalLinkage, llvm::Null, ReplaceUsesOfMallocWithGlobal(), RewriteUsesOfLoadForHeapSRoA(), SI, llvm::BasicBlock::splitBasicBlock(), llvm::AArch64DB::ST, llvm::Value::user_begin(), and llvm::Value::user_end().
Referenced by TryToOptimizeStoreOfMallocToGlobal().
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Definition at line 1877 of file GlobalOpt.cpp.
References llvm::CS, llvm::Function::getAttributes(), llvm::CallSiteBase< FunTy, BBTy, ValTy, UserTy, InstrTy, CallTy, InvokeTy, IterTy >::getAttributes(), llvm::Function::getContext(), llvm::Function::setAttributes(), llvm::CallSiteBase< FunTy, BBTy, ValTy, UserTy, InstrTy, CallTy, InvokeTy, IterTy >::setAttributes(), StripNest(), and llvm::Value::users().
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ReplaceUsesOfMallocWithGlobal - The Alloc pointer is stored into GV somewhere.
Transform all uses of the allocation into loads from the global and uses of the resultant pointer. Further, delete the store into GV. This assumes that these value pass the 'ValueIsOnlyUsedLocallyOrStoredToOneGlobal' predicate.
Definition at line 1006 of file GlobalOpt.cpp.
References llvm::Instruction::eraseFromParent(), llvm::Value::getName(), llvm::User::replaceUsesOfWith(), SI, llvm::Value::use_begin(), llvm::Value::use_empty(), and llvm::Value::user_begin().
Referenced by PerformHeapAllocSRoA().
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RewriteHeapSROALoadUser - Given a load instruction and a value derived from the load, rewrite the derived value to use the HeapSRoA'd load.
Definition at line 1191 of file GlobalOpt.cpp.
References llvm::GetElementPtrInst::Create(), GetHeapSROAValue(), llvm::Value::getName(), llvm::Constant::getNullValue(), llvm::Value::getType(), llvm::SmallVectorTemplateBase< T, isPodLike >::push_back(), llvm::Value::replaceAllUsesWith(), llvm::Value::user_begin(), and llvm::Value::user_end().
Referenced by RewriteUsesOfLoadForHeapSRoA().
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RewriteUsesOfLoadForHeapSRoA - We are performing Heap SRoA on a global.
Ptr is a value loaded from the global. Eliminate all uses of Ptr, making them use FieldGlobals instead. All uses of loaded values satisfy AllGlobalLoadUsesSimpleEnoughForHeapSRA.
Definition at line 1255 of file GlobalOpt.cpp.
References llvm::iplist< NodeTy, Traits >::erase(), llvm::Instruction::eraseFromParent(), RewriteHeapSROALoadUser(), llvm::Value::use_empty(), llvm::Value::user_begin(), and llvm::Value::user_end().
Referenced by PerformHeapAllocSRoA().
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Definition at line 2714 of file GlobalOpt.cpp.
References llvm::GlobalValue::AppendingLinkage, llvm::array_pod_sort(), compareNames(), llvm::SmallPtrSetImplBase::empty(), llvm::GlobalVariable::eraseFromParent(), llvm::ArrayType::get(), llvm::ConstantArray::get(), llvm::Value::getContext(), llvm::Type::getInt8PtrTy(), llvm::GlobalValue::getParent(), llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(), llvm::AArch64CC::NV, llvm::GlobalVariable::removeFromParent(), llvm::GlobalObject::setSection(), and llvm::Value::takeName().
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SRAGlobal - 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 472 of file GlobalOpt.cpp.
References llvm::GetElementPtrInst::Create(), llvm::dbgs(), DEBUG, llvm::iplist< NodeTy, Traits >::erase(), GEP, llvm::DataLayout::getABITypeAlignment(), llvm::PointerType::getAddressSpace(), llvm::GlobalObject::getAlignment(), llvm::Value::getContext(), llvm::StructLayout::getElementOffset(), llvm::ConstantExpr::getGetElementPtr(), llvm::Module::getGlobalList(), llvm::GlobalVariable::getInitializer(), llvm::Type::getInt32Ty(), llvm::Value::getName(), llvm::Constant::getNullValue(), llvm::User::getNumOperands(), llvm::User::getOperand(), llvm::GlobalValue::getParent(), llvm::DataLayout::getStructLayout(), llvm::GlobalValue::getThreadLocalMode(), llvm::GlobalValue::getType(), llvm::DataLayout::getTypeAllocSize(), GlobalUsersSafeToSRA(), llvm::GlobalValue::hasLocalLinkage(), llvm::Value::hasNUsesOrMore(), llvm::tgtok::In, llvm::iplist< NodeTy, Traits >::insert(), llvm::GlobalValue::InternalLinkage, llvm::GlobalVariable::isConstant(), llvm::MinAlign(), llvm::SmallVectorTemplateBase< T, isPodLike >::push_back(), llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), llvm::Value::replaceAllUsesWith(), llvm::GlobalObject::setAlignment(), llvm::Value::use_empty(), and llvm::Value::user_back().
| STATISTIC | ( | NumMarked | , |
| "Number of globals marked constant" | |||
| ) |
| STATISTIC | ( | NumUnnamed | , |
| "Number of globals marked unnamed_addr" | |||
| ) |
| STATISTIC | ( | NumHeapSRA | , |
| "Number of heap objects SRA'd" | |||
| ) |
| STATISTIC | ( | NumSubstitute | , |
| "Number of globals with initializers stored into them" | |||
| ) |
| STATISTIC | ( | NumDeleted | , |
| "Number of globals deleted" | |||
| ) |
| STATISTIC | ( | NumFnDeleted | , |
| "Number of functions 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" | |||
| ) |
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Definition at line 1864 of file GlobalOpt.cpp.
References llvm::AttributeSet::getNumSlots(), llvm::AttributeSet::getSlotAttributes(), llvm::AttributeSet::getSlotIndex(), llvm::AttributeSet::hasAttribute(), llvm::Attribute::Nest, and llvm::AttributeSet::removeAttribute().
Referenced by RemoveNestAttribute().
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TryToOptimizeStoreOfMallocToGlobal - This function is called when we see a pointer global variable with a single value stored it that is a malloc or cast of malloc.
Definition at line 1460 of file GlobalOpt.cpp.
References AllGlobalLoadUsesSimpleEnoughForHeapSRA(), AllUsesOfLoadedValueWillTrapIfNull(), llvm::CallInst::CreateMalloc(), llvm::dyn_cast(), llvm::Instruction::eraseFromParent(), llvm::ConstantInt::get(), llvm::CallInst::getArgOperand(), llvm::DataLayout::getIntPtrType(), llvm::getMallocAllocatedType(), llvm::getMallocArraySize(), llvm::Value::getName(), llvm::StructType::getNumElements(), llvm::StructLayout::getSizeInBytes(), llvm::DataLayout::getStructLayout(), llvm::Value::getType(), llvm::DataLayout::getTypeAllocSize(), llvm::Type::isSized(), llvm::NotAtomic, OptimizeGlobalAddressOfMalloc(), PerformHeapAllocSRoA(), llvm::Value::replaceAllUsesWith(), and ValueIsOnlyUsedLocallyOrStoredToOneGlobal().
Referenced by OptimizeOnceStoredGlobal().
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TryToShrinkGlobalToBoolean - 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 1594 of file GlobalOpt.cpp.
References llvm::SelectInst::Create(), llvm::dbgs(), DEBUG, llvm::Instruction::eraseFromParent(), llvm::GlobalVariable::eraseFromParent(), llvm::ConstantInt::get(), llvm::PointerType::getAddressSpace(), llvm::Value::getContext(), llvm::SequentialType::getElementType(), llvm::ConstantInt::getFalse(), llvm::Module::getGlobalList(), llvm::GlobalVariable::getInitializer(), llvm::Type::getInt1Ty(), llvm::Value::getName(), llvm::User::getOperand(), llvm::LoadInst::getOrdering(), llvm::GlobalValue::getParent(), llvm::LoadInst::getSynchScope(), llvm::GlobalValue::getThreadLocalMode(), llvm::GlobalValue::getType(), llvm::Value::getType(), llvm::iplist< NodeTy, Traits >::insert(), llvm::GlobalValue::InternalLinkage, llvm::Type::isFloatingPointTy(), llvm::Constant::isNullValue(), llvm::Type::isPointerTy(), llvm::Type::isVectorTy(), llvm::Value::replaceAllUsesWith(), SI, llvm::Value::takeName(), llvm::Value::use_empty(), llvm::Value::user_back(), and llvm::Value::users().
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ValueIsOnlyUsedLocallyOrStoredToOneGlobal - Scan the use-list of V checking to make sure that there are no complex uses of V.
We permit simple things like dereferencing the pointer, but not storing through the address, unless it is to the specified global.
Definition at line 958 of file GlobalOpt.cpp.
References llvm::User::getNumOperands(), llvm::SmallPtrSetImpl< PtrType >::insert(), SI, and llvm::Value::users().
Referenced by TryToOptimizeStoreOfMallocToGlobal().
| Global Variable false |
Definition at line 98 of file GlobalOpt.cpp.
| globalopt |
Definition at line 98 of file GlobalOpt.cpp.
| Global Variable Optimizer |
Definition at line 98 of file GlobalOpt.cpp.
1.8.6