mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-13 20:32:21 +00:00
refactor the MemoryBuiltin analysis:
- provide more extensive set of functions to detect library allocation functions (e.g., malloc, calloc, strdup, etc) - provide an API to compute the size and offset of an object pointed by Move a few clients (GVN, AA, instcombine, ...) to the new API. This implementation is a lot more aggressive than each of the custom implementations being replaced. Patch reviewed by Nick Lewycky and Chandler Carruth, thanks. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158919 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nuno Lopes
parent
2114a8aaba
commit
9e72a79ef4
@ -15,6 +15,14 @@
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#ifndef LLVM_ANALYSIS_MEMORYBUILTINS_H
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#define LLVM_ANALYSIS_MEMORYBUILTINS_H
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/SmallPtrSet.h"
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#include "llvm/Operator.h"
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#include "llvm/Support/DataTypes.h"
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#include "llvm/Support/InstVisitor.h"
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#include "llvm/Support/IRBuilder.h"
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#include "llvm/Support/TargetFolder.h"
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namespace llvm {
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class CallInst;
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class PointerType;
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@ -22,24 +30,50 @@ class TargetData;
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class Type;
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class Value;
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/// \brief Tests if a value is a call to a library function that allocates or
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/// reallocates memory (either malloc, calloc, realloc, or strdup like).
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bool isAllocationFn(const Value *V, bool LookThroughBitCast = false);
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/// \brief Tests if a value is a call to a function that returns a NoAlias
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/// pointer (including malloc/calloc/strdup-like functions).
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bool isNoAliasFn(const Value *V, bool LookThroughBitCast = false);
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/// \brief Tests if a value is a call to a library function that allocates
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/// uninitialized memory (such as malloc).
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bool isMallocLikeFn(const Value *V, bool LookThroughBitCast = false);
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/// \brief Tests if a value is a call to a library function that allocates
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/// zero-filled memory (such as calloc).
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bool isCallocLikeFn(const Value *V, bool LookThroughBitCast = false);
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/// \brief Tests if a value is a call to a library function that allocates
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/// memory (either malloc, calloc, or strdup like).
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bool isAllocLikeFn(const Value *V, bool LookThroughBitCast = false);
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/// \brief Tests if a value is a call to a library function that reallocates
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/// memory (such as realloc).
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bool isReallocLikeFn(const Value *V, bool LookThroughBitCast = false);
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//===----------------------------------------------------------------------===//
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// malloc Call Utility Functions.
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//
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/// isMalloc - Returns true if the value is either a malloc call or a bitcast of
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/// the result of a malloc call
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bool isMalloc(const Value *I);
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/// extractMallocCall - Returns the corresponding CallInst if the instruction
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/// is a malloc call. Since CallInst::CreateMalloc() only creates calls, we
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/// ignore InvokeInst here.
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const CallInst *extractMallocCall(const Value *I);
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CallInst *extractMallocCall(Value *I);
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static inline CallInst *extractMallocCall(Value *I) {
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return const_cast<CallInst*>(extractMallocCall((const Value*)I));
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}
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/// extractMallocCallFromBitCast - Returns the corresponding CallInst if the
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/// instruction is a bitcast of the result of a malloc call.
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const CallInst *extractMallocCallFromBitCast(const Value *I);
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CallInst *extractMallocCallFromBitCast(Value *I);
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static inline CallInst *extractMallocCallFromBitCast(Value *I) {
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return const_cast<CallInst*>(extractMallocCallFromBitCast((const Value*)I));
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}
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/// isArrayMalloc - Returns the corresponding CallInst if the instruction
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/// is a call to malloc whose array size can be determined and the array size
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@ -67,7 +101,7 @@ Type *getMallocAllocatedType(const CallInst *CI);
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/// determined.
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Value *getMallocArraySize(CallInst *CI, const TargetData *TD,
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bool LookThroughSExt = false);
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//===----------------------------------------------------------------------===//
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// calloc Call Utility Functions.
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@ -76,7 +110,9 @@ Value *getMallocArraySize(CallInst *CI, const TargetData *TD,
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/// extractCallocCall - Returns the corresponding CallInst if the instruction
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/// is a calloc call.
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const CallInst *extractCallocCall(const Value *I);
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CallInst *extractCallocCall(Value *I);
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static inline CallInst *extractCallocCall(Value *I) {
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return const_cast<CallInst*>(extractCallocCall((const Value*)I));
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}
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//===----------------------------------------------------------------------===//
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@ -90,6 +126,126 @@ static inline CallInst *isFreeCall(Value *I) {
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return const_cast<CallInst*>(isFreeCall((const Value*)I));
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}
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//===----------------------------------------------------------------------===//
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// Utility functions to compute size of objects.
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//
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/// \brief Compute the size of the object pointed by Ptr. Returns true and the
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/// object size in Size if successful, and false otherwise.
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/// If RoundToAlign is true, then Size is rounded up to the aligment of allocas,
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/// byval arguments, and global variables.
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bool getObjectSize(const Value *Ptr, uint64_t &Size, const TargetData *TD,
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bool RoundToAlign = false);
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typedef std::pair<APInt, APInt> SizeOffsetType;
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/// \brief Evaluate the size and offset of an object ponted by a Value*
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/// statically. Fails if size or offset are not known at compile time.
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class ObjectSizeOffsetVisitor
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: public InstVisitor<ObjectSizeOffsetVisitor, SizeOffsetType> {
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const TargetData *TD;
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bool RoundToAlign;
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unsigned IntTyBits;
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APInt Zero;
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APInt align(APInt Size, uint64_t Align);
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SizeOffsetType unknown() {
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return std::make_pair(APInt(), APInt());
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}
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public:
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ObjectSizeOffsetVisitor(const TargetData *TD, LLVMContext &Context,
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bool RoundToAlign = false);
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SizeOffsetType compute(Value *V);
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bool knownSize(SizeOffsetType &SizeOffset) {
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return SizeOffset.first.getBitWidth() > 1;
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}
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bool knownOffset(SizeOffsetType &SizeOffset) {
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return SizeOffset.second.getBitWidth() > 1;
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}
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bool bothKnown(SizeOffsetType &SizeOffset) {
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return knownSize(SizeOffset) && knownOffset(SizeOffset);
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}
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SizeOffsetType visitAllocaInst(AllocaInst &I);
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SizeOffsetType visitArgument(Argument &A);
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SizeOffsetType visitCallSite(CallSite CS);
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SizeOffsetType visitConstantPointerNull(ConstantPointerNull&);
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SizeOffsetType visitExtractValueInst(ExtractValueInst &I);
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SizeOffsetType visitGEPOperator(GEPOperator &GEP);
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SizeOffsetType visitGlobalVariable(GlobalVariable &GV);
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SizeOffsetType visitIntToPtrInst(IntToPtrInst&);
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SizeOffsetType visitLoadInst(LoadInst &I);
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SizeOffsetType visitPHINode(PHINode&);
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SizeOffsetType visitSelectInst(SelectInst &I);
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SizeOffsetType visitUndefValue(UndefValue&);
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SizeOffsetType visitInstruction(Instruction &I);
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};
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typedef std::pair<Value*, Value*> SizeOffsetEvalType;
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typedef IRBuilder<true, TargetFolder> BuilderTy;
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typedef DenseMap<const Value*, SizeOffsetEvalType> CacheMapTy;
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typedef SmallPtrSet<const Value*, 8> PtrSetTy;
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/// \brief Evaluate the size and offset of an object ponted by a Value*.
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/// May create code to compute the result at run-time.
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class ObjectSizeOffsetEvaluator
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: public InstVisitor<ObjectSizeOffsetEvaluator, SizeOffsetEvalType> {
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const TargetData *TD;
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LLVMContext &Context;
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BuilderTy Builder;
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ObjectSizeOffsetVisitor Visitor;
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IntegerType *IntTy;
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Value *Zero;
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CacheMapTy CacheMap;
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PtrSetTy SeenVals;
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SizeOffsetEvalType unknown() {
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return std::make_pair((Value*)0, (Value*)0);
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}
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SizeOffsetEvalType compute_(Value *V);
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public:
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ObjectSizeOffsetEvaluator(const TargetData *TD, LLVMContext &Context);
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SizeOffsetEvalType compute(Value *V);
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bool knownSize(SizeOffsetEvalType &SizeOffset) {
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return SizeOffset.first;
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}
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bool knownOffset(SizeOffsetEvalType &SizeOffset) {
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return SizeOffset.second;
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}
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bool anyKnown(SizeOffsetEvalType &SizeOffset) {
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return knownSize(SizeOffset) || knownOffset(SizeOffset);
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}
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bool bothKnown(SizeOffsetEvalType &SizeOffset) {
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return knownSize(SizeOffset) && knownOffset(SizeOffset);
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}
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SizeOffsetEvalType visitAllocaInst(AllocaInst &I);
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SizeOffsetEvalType visitCallSite(CallSite CS);
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SizeOffsetEvalType visitGEPOperator(GEPOperator &GEP);
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SizeOffsetEvalType visitIntToPtrInst(IntToPtrInst&);
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SizeOffsetEvalType visitLoadInst(LoadInst &I);
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SizeOffsetEvalType visitPHINode(PHINode &PHI);
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SizeOffsetEvalType visitSelectInst(SelectInst &I);
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SizeOffsetEvalType visitInstruction(Instruction &I);
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};
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} // End llvm namespace
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#endif
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@ -86,47 +86,10 @@ static bool isEscapeSource(const Value *V) {
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/// UnknownSize if unknown.
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static uint64_t getObjectSize(const Value *V, const TargetData &TD,
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bool RoundToAlign = false) {
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Type *AccessTy;
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unsigned Align;
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if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
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if (!GV->hasDefinitiveInitializer())
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return AliasAnalysis::UnknownSize;
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AccessTy = GV->getType()->getElementType();
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Align = GV->getAlignment();
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} else if (const AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
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if (!AI->isArrayAllocation())
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AccessTy = AI->getType()->getElementType();
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else
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return AliasAnalysis::UnknownSize;
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Align = AI->getAlignment();
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} else if (const CallInst* CI = extractMallocCall(V)) {
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if (!RoundToAlign && !isArrayMalloc(V, &TD))
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// The size is the argument to the malloc call.
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if (const ConstantInt* C = dyn_cast<ConstantInt>(CI->getArgOperand(0)))
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return C->getZExtValue();
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return AliasAnalysis::UnknownSize;
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} else if (const Argument *A = dyn_cast<Argument>(V)) {
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if (A->hasByValAttr()) {
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AccessTy = cast<PointerType>(A->getType())->getElementType();
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Align = A->getParamAlignment();
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} else {
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return AliasAnalysis::UnknownSize;
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}
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} else {
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return AliasAnalysis::UnknownSize;
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}
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if (!AccessTy->isSized())
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return AliasAnalysis::UnknownSize;
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uint64_t Size = TD.getTypeAllocSize(AccessTy);
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// If there is an explicitly specified alignment, and we need to
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// take alignment into account, round up the size. (If the alignment
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// is implicit, getTypeAllocSize is sufficient.)
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if (RoundToAlign && Align)
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Size = RoundUpToAlignment(Size, Align);
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return Size;
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uint64_t Size;
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if (getObjectSize(V, Size, &TD, RoundToAlign))
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return Size;
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return AliasAnalysis::UnknownSize;
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}
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/// isObjectSmallerThan - Return true if we can prove that the object specified
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@ -329,15 +329,8 @@ bool GlobalsModRef::AnalyzeIndirectGlobalMemory(GlobalValue *GV) {
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// Check the value being stored.
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Value *Ptr = GetUnderlyingObject(SI->getOperand(0));
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if (isMalloc(Ptr)) {
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// Okay, easy case.
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} else if (CallInst *CI = dyn_cast<CallInst>(Ptr)) {
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Function *F = CI->getCalledFunction();
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if (!F || !F->isDeclaration()) return false; // Too hard to analyze.
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if (F->getName() != "calloc") return false; // Not calloc.
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} else {
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if (!isAllocLikeFn(Ptr))
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return false; // Too hard to analyze.
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}
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// Analyze all uses of the allocation. If any of them are used in a
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// non-simple way (e.g. stored to another global) bail out.
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@ -454,19 +447,18 @@ void GlobalsModRef::AnalyzeCallGraph(CallGraph &CG, Module &M) {
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for (inst_iterator II = inst_begin(SCC[i]->getFunction()),
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E = inst_end(SCC[i]->getFunction());
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II != E && FunctionEffect != ModRef; ++II)
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if (isa<LoadInst>(*II)) {
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if (LoadInst *LI = dyn_cast<LoadInst>(&*II)) {
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FunctionEffect |= Ref;
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if (cast<LoadInst>(*II).isVolatile())
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if (LI->isVolatile())
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// Volatile loads may have side-effects, so mark them as writing
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// memory (for example, a flag inside the processor).
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FunctionEffect |= Mod;
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} else if (isa<StoreInst>(*II)) {
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} else if (StoreInst *SI = dyn_cast<StoreInst>(&*II)) {
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FunctionEffect |= Mod;
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if (cast<StoreInst>(*II).isVolatile())
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if (SI->isVolatile())
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// Treat volatile stores as reading memory somewhere.
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FunctionEffect |= Ref;
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} else if (isMalloc(&cast<Instruction>(*II)) ||
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isFreeCall(&cast<Instruction>(*II))) {
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} else if (isAllocationFn(&*II) || isFreeCall(&*II)) {
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FunctionEffect |= ModRef;
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} else if (IntrinsicInst *Intrinsic = dyn_cast<IntrinsicInst>(&*II)) {
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// The callgraph doesn't include intrinsic calls.
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@ -12,80 +12,165 @@
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//
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "memory-builtins"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/Analysis/MemoryBuiltins.h"
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#include "llvm/Constants.h"
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#include "llvm/GlobalVariable.h"
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#include "llvm/Instructions.h"
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#include "llvm/Intrinsics.h"
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#include "llvm/Metadata.h"
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#include "llvm/Module.h"
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#include "llvm/Analysis/ValueTracking.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/MathExtras.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Target/TargetData.h"
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#include "llvm/Transforms/Utils/Local.h"
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using namespace llvm;
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//===----------------------------------------------------------------------===//
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// malloc Call Utility Functions.
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//
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enum AllocType {
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MallocLike = 1<<0, // allocates
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CallocLike = 1<<1, // allocates + bzero
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ReallocLike = 1<<2, // reallocates
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StrDupLike = 1<<3,
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AllocLike = MallocLike | CallocLike | StrDupLike,
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AnyAlloc = MallocLike | CallocLike | ReallocLike | StrDupLike
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};
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/// isMalloc - Returns true if the value is either a malloc call or a
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/// bitcast of the result of a malloc call.
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bool llvm::isMalloc(const Value *I) {
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return extractMallocCall(I) || extractMallocCallFromBitCast(I);
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}
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struct AllocFnsTy {
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const char *Name;
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AllocType AllocTy;
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unsigned char NumParams;
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// First and Second size parameters (or -1 if unused)
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unsigned char FstParam, SndParam;
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};
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static bool isMallocCall(const CallInst *CI) {
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static const AllocFnsTy AllocationFnData[] = {
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{"malloc", MallocLike, 1, 0, -1},
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{"valloc", MallocLike, 1, 0, -1},
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{"_Znwj", MallocLike, 1, 0, -1}, // operator new(unsigned int)
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{"_Znwm", MallocLike, 1, 0, -1}, // operator new(unsigned long)
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{"_Znaj", MallocLike, 1, 0, -1}, // operator new[](unsigned int)
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{"_Znam", MallocLike, 1, 0, -1}, // operator new[](unsigned long)
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{"posix_memalign", MallocLike, 3, 2, -1},
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{"calloc", CallocLike, 2, 0, 1},
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{"realloc", ReallocLike, 2, 1, -1},
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{"reallocf", ReallocLike, 2, 1, -1},
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{"strdup", StrDupLike, 1, -1, -1},
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{"strndup", StrDupLike, 2, -1, -1}
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};
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static Function *getCalledFunction(const Value *V, bool LookThroughBitCast) {
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if (LookThroughBitCast)
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V = V->stripPointerCasts();
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const CallInst *CI = dyn_cast<CallInst>(V);
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if (!CI)
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return false;
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return 0;
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Function *Callee = CI->getCalledFunction();
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if (Callee == 0 || !Callee->isDeclaration())
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return false;
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if (Callee->getName() != "malloc" &&
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Callee->getName() != "_Znwj" && // operator new(unsigned int)
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Callee->getName() != "_Znwm" && // operator new(unsigned long)
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Callee->getName() != "_Znaj" && // operator new[](unsigned int)
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Callee->getName() != "_Znam") // operator new[](unsigned long)
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return false;
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if (!Callee || !Callee->isDeclaration())
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return 0;
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return Callee;
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}
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// Check malloc prototype.
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// FIXME: workaround for PR5130, this will be obsolete when a nobuiltin
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// attribute will exist.
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/// \brief Returns the allocation data for the given value if it is a call to a
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/// known allocation function, and NULL otherwise.
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static const AllocFnsTy *getAllocationData(const Value *V, AllocType AllocTy,
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bool LookThroughBitCast = false) {
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Function *Callee = getCalledFunction(V, LookThroughBitCast);
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if (!Callee)
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return 0;
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unsigned i = 0;
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bool found = false;
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for ( ; i < array_lengthof(AllocationFnData); ++i) {
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if (Callee->getName() == AllocationFnData[i].Name) {
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found = true;
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break;
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}
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}
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if (!found)
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return 0;
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const AllocFnsTy *FnData = &AllocationFnData[i];
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if ((FnData->AllocTy & AllocTy) == 0)
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return 0;
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// Check function prototype.
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// FIXME: Check the nobuiltin metadata?? (PR5130)
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unsigned FstParam = FnData->FstParam;
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unsigned SndParam = FnData->SndParam;
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FunctionType *FTy = Callee->getFunctionType();
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return FTy->getReturnType() == Type::getInt8PtrTy(FTy->getContext()) &&
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FTy->getNumParams() == 1 &&
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(FTy->getParamType(0)->isIntegerTy(32) ||
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FTy->getParamType(0)->isIntegerTy(64));
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||||
|
||||
if (FTy->getReturnType() == Type::getInt8PtrTy(FTy->getContext()) &&
|
||||
FTy->getNumParams() == FnData->NumParams &&
|
||||
(FstParam == (unsigned char)-1 ||
|
||||
(FTy->getParamType(FstParam)->isIntegerTy(32) ||
|
||||
FTy->getParamType(FstParam)->isIntegerTy(64))) &&
|
||||
(SndParam == (unsigned char)-1 ||
|
||||
FTy->getParamType(SndParam)->isIntegerTy(32) ||
|
||||
FTy->getParamType(SndParam)->isIntegerTy(64)))
|
||||
return FnData;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static bool hasNoAliasAttr(const Value *V, bool LookThroughBitCast) {
|
||||
Function *Callee = getCalledFunction(V, LookThroughBitCast);
|
||||
return Callee && Callee->hasFnAttr(Attribute::NoAlias);
|
||||
}
|
||||
|
||||
|
||||
/// \brief Tests if a value is a call to a library function that allocates or
|
||||
/// reallocates memory (either malloc, calloc, realloc, or strdup like).
|
||||
bool llvm::isAllocationFn(const Value *V, bool LookThroughBitCast) {
|
||||
return getAllocationData(V, AnyAlloc, LookThroughBitCast);
|
||||
}
|
||||
|
||||
/// \brief Tests if a value is a call to a function that returns a NoAlias
|
||||
/// pointer (including malloc/calloc/strdup-like functions).
|
||||
bool llvm::isNoAliasFn(const Value *V, bool LookThroughBitCast) {
|
||||
return isAllocLikeFn(V, LookThroughBitCast) ||
|
||||
hasNoAliasAttr(V, LookThroughBitCast);
|
||||
}
|
||||
|
||||
/// \brief Tests if a value is a call to a library function that allocates
|
||||
/// uninitialized memory (such as malloc).
|
||||
bool llvm::isMallocLikeFn(const Value *V, bool LookThroughBitCast) {
|
||||
return getAllocationData(V, MallocLike, LookThroughBitCast);
|
||||
}
|
||||
|
||||
/// \brief Tests if a value is a call to a library function that allocates
|
||||
/// zero-filled memory (such as calloc).
|
||||
bool llvm::isCallocLikeFn(const Value *V, bool LookThroughBitCast) {
|
||||
return getAllocationData(V, CallocLike, LookThroughBitCast);
|
||||
}
|
||||
|
||||
/// \brief Tests if a value is a call to a library function that allocates
|
||||
/// memory (either malloc, calloc, or strdup like).
|
||||
bool llvm::isAllocLikeFn(const Value *V, bool LookThroughBitCast) {
|
||||
return getAllocationData(V, AllocLike, LookThroughBitCast);
|
||||
}
|
||||
|
||||
/// \brief Tests if a value is a call to a library function that reallocates
|
||||
/// memory (such as realloc).
|
||||
bool llvm::isReallocLikeFn(const Value *V, bool LookThroughBitCast) {
|
||||
return getAllocationData(V, ReallocLike, LookThroughBitCast);
|
||||
}
|
||||
|
||||
/// extractMallocCall - Returns the corresponding CallInst if the instruction
|
||||
/// is a malloc call. Since CallInst::CreateMalloc() only creates calls, we
|
||||
/// ignore InvokeInst here.
|
||||
const CallInst *llvm::extractMallocCall(const Value *I) {
|
||||
const CallInst *CI = dyn_cast<CallInst>(I);
|
||||
return (isMallocCall(CI)) ? CI : NULL;
|
||||
}
|
||||
|
||||
CallInst *llvm::extractMallocCall(Value *I) {
|
||||
CallInst *CI = dyn_cast<CallInst>(I);
|
||||
return (isMallocCall(CI)) ? CI : NULL;
|
||||
}
|
||||
|
||||
static bool isBitCastOfMallocCall(const BitCastInst *BCI) {
|
||||
if (!BCI)
|
||||
return false;
|
||||
|
||||
return isMallocCall(dyn_cast<CallInst>(BCI->getOperand(0)));
|
||||
return isMallocLikeFn(I) ? cast<CallInst>(I) : 0;
|
||||
}
|
||||
|
||||
/// extractMallocCallFromBitCast - Returns the corresponding CallInst if the
|
||||
/// instruction is a bitcast of the result of a malloc call.
|
||||
CallInst *llvm::extractMallocCallFromBitCast(Value *I) {
|
||||
BitCastInst *BCI = dyn_cast<BitCastInst>(I);
|
||||
return (isBitCastOfMallocCall(BCI)) ? cast<CallInst>(BCI->getOperand(0))
|
||||
: NULL;
|
||||
}
|
||||
|
||||
const CallInst *llvm::extractMallocCallFromBitCast(const Value *I) {
|
||||
const BitCastInst *BCI = dyn_cast<BitCastInst>(I);
|
||||
return (isBitCastOfMallocCall(BCI)) ? cast<CallInst>(BCI->getOperand(0))
|
||||
: NULL;
|
||||
return BCI ? extractMallocCall(BCI->getOperand(0)) : 0;
|
||||
}
|
||||
|
||||
static Value *computeArraySize(const CallInst *CI, const TargetData *TD,
|
||||
@ -134,7 +219,7 @@ const CallInst *llvm::isArrayMalloc(const Value *I, const TargetData *TD) {
|
||||
/// 1: PointerType is the bitcast's result type.
|
||||
/// >1: Unique PointerType cannot be determined, return NULL.
|
||||
PointerType *llvm::getMallocType(const CallInst *CI) {
|
||||
assert(isMalloc(CI) && "getMallocType and not malloc call");
|
||||
assert(isMallocLikeFn(CI) && "getMallocType and not malloc call");
|
||||
|
||||
PointerType *MallocType = NULL;
|
||||
unsigned NumOfBitCastUses = 0;
|
||||
@ -176,53 +261,17 @@ Type *llvm::getMallocAllocatedType(const CallInst *CI) {
|
||||
/// determined.
|
||||
Value *llvm::getMallocArraySize(CallInst *CI, const TargetData *TD,
|
||||
bool LookThroughSExt) {
|
||||
assert(isMalloc(CI) && "getMallocArraySize and not malloc call");
|
||||
assert(isMallocLikeFn(CI) && "getMallocArraySize and not malloc call");
|
||||
return computeArraySize(CI, TD, LookThroughSExt);
|
||||
}
|
||||
|
||||
|
||||
//===----------------------------------------------------------------------===//
|
||||
// calloc Call Utility Functions.
|
||||
//
|
||||
|
||||
static bool isCallocCall(const CallInst *CI) {
|
||||
if (!CI)
|
||||
return false;
|
||||
|
||||
Function *Callee = CI->getCalledFunction();
|
||||
if (Callee == 0 || !Callee->isDeclaration())
|
||||
return false;
|
||||
if (Callee->getName() != "calloc")
|
||||
return false;
|
||||
|
||||
// Check malloc prototype.
|
||||
// FIXME: workaround for PR5130, this will be obsolete when a nobuiltin
|
||||
// attribute exists.
|
||||
FunctionType *FTy = Callee->getFunctionType();
|
||||
return FTy->getReturnType() == Type::getInt8PtrTy(FTy->getContext()) &&
|
||||
FTy->getNumParams() == 2 &&
|
||||
((FTy->getParamType(0)->isIntegerTy(32) &&
|
||||
FTy->getParamType(1)->isIntegerTy(32)) ||
|
||||
(FTy->getParamType(0)->isIntegerTy(64) &&
|
||||
FTy->getParamType(1)->isIntegerTy(64)));
|
||||
}
|
||||
|
||||
/// extractCallocCall - Returns the corresponding CallInst if the instruction
|
||||
/// is a calloc call.
|
||||
const CallInst *llvm::extractCallocCall(const Value *I) {
|
||||
const CallInst *CI = dyn_cast<CallInst>(I);
|
||||
return isCallocCall(CI) ? CI : 0;
|
||||
return isCallocLikeFn(I) ? cast<CallInst>(I) : 0;
|
||||
}
|
||||
|
||||
CallInst *llvm::extractCallocCall(Value *I) {
|
||||
CallInst *CI = dyn_cast<CallInst>(I);
|
||||
return isCallocCall(CI) ? CI : 0;
|
||||
}
|
||||
|
||||
|
||||
//===----------------------------------------------------------------------===//
|
||||
// free Call Utility Functions.
|
||||
//
|
||||
|
||||
/// isFreeCall - Returns non-null if the value is a call to the builtin free()
|
||||
const CallInst *llvm::isFreeCall(const Value *I) {
|
||||
@ -251,3 +300,388 @@ const CallInst *llvm::isFreeCall(const Value *I) {
|
||||
|
||||
return CI;
|
||||
}
|
||||
|
||||
|
||||
|
||||
//===----------------------------------------------------------------------===//
|
||||
// Utility functions to compute size of objects.
|
||||
//
|
||||
|
||||
|
||||
/// \brief Compute the size of the object pointed by Ptr. Returns true and the
|
||||
/// object size in Size if successful, and false otherwise.
|
||||
/// If RoundToAlign is true, then Size is rounded up to the aligment of allocas,
|
||||
/// byval arguments, and global variables.
|
||||
bool llvm::getObjectSize(const Value *Ptr, uint64_t &Size, const TargetData *TD,
|
||||
bool RoundToAlign) {
|
||||
if (!TD)
|
||||
return false;
|
||||
|
||||
ObjectSizeOffsetVisitor Visitor(TD, Ptr->getContext(), RoundToAlign);
|
||||
SizeOffsetType Data = Visitor.compute(const_cast<Value*>(Ptr));
|
||||
if (!Visitor.bothKnown(Data))
|
||||
return false;
|
||||
|
||||
APInt ObjSize = Data.first, Offset = Data.second;
|
||||
// check for overflow
|
||||
if (Offset.slt(0) || ObjSize.ult(Offset))
|
||||
Size = 0;
|
||||
else
|
||||
Size = (ObjSize - Offset).getZExtValue();
|
||||
return true;
|
||||
}
|
||||
|
||||
|
||||
STATISTIC(ObjectVisitorArgument,
|
||||
"Number of arguments with unsolved size and offset");
|
||||
STATISTIC(ObjectVisitorLoad,
|
||||
"Number of load instructions with unsolved size and offset");
|
||||
|
||||
|
||||
APInt ObjectSizeOffsetVisitor::align(APInt Size, uint64_t Align) {
|
||||
if (RoundToAlign && Align)
|
||||
return APInt(IntTyBits, RoundUpToAlignment(Size.getZExtValue(), Align));
|
||||
return Size;
|
||||
}
|
||||
|
||||
ObjectSizeOffsetVisitor::ObjectSizeOffsetVisitor(const TargetData *TD,
|
||||
LLVMContext &Context,
|
||||
bool RoundToAlign)
|
||||
: TD(TD), RoundToAlign(RoundToAlign) {
|
||||
IntegerType *IntTy = TD->getIntPtrType(Context);
|
||||
IntTyBits = IntTy->getBitWidth();
|
||||
Zero = APInt::getNullValue(IntTyBits);
|
||||
}
|
||||
|
||||
SizeOffsetType ObjectSizeOffsetVisitor::compute(Value *V) {
|
||||
V = V->stripPointerCasts();
|
||||
|
||||
if (GEPOperator *GEP = dyn_cast<GEPOperator>(V))
|
||||
return visitGEPOperator(*GEP);
|
||||
if (Instruction *I = dyn_cast<Instruction>(V))
|
||||
return visit(*I);
|
||||
if (Argument *A = dyn_cast<Argument>(V))
|
||||
return visitArgument(*A);
|
||||
if (ConstantPointerNull *P = dyn_cast<ConstantPointerNull>(V))
|
||||
return visitConstantPointerNull(*P);
|
||||
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
|
||||
return visitGlobalVariable(*GV);
|
||||
if (UndefValue *UV = dyn_cast<UndefValue>(V))
|
||||
return visitUndefValue(*UV);
|
||||
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
|
||||
if (CE->getOpcode() == Instruction::IntToPtr)
|
||||
return unknown(); // clueless
|
||||
|
||||
DEBUG(dbgs() << "ObjectSizeOffsetVisitor::compute() unhandled value: " << *V
|
||||
<< '\n');
|
||||
return unknown();
|
||||
}
|
||||
|
||||
SizeOffsetType ObjectSizeOffsetVisitor::visitAllocaInst(AllocaInst &I) {
|
||||
if (!I.getAllocatedType()->isSized())
|
||||
return unknown();
|
||||
|
||||
APInt Size(IntTyBits, TD->getTypeAllocSize(I.getAllocatedType()));
|
||||
if (!I.isArrayAllocation())
|
||||
return std::make_pair(align(Size, I.getAlignment()), Zero);
|
||||
|
||||
Value *ArraySize = I.getArraySize();
|
||||
if (const ConstantInt *C = dyn_cast<ConstantInt>(ArraySize)) {
|
||||
Size *= C->getValue().zextOrSelf(IntTyBits);
|
||||
return std::make_pair(align(Size, I.getAlignment()), Zero);
|
||||
}
|
||||
return unknown();
|
||||
}
|
||||
|
||||
SizeOffsetType ObjectSizeOffsetVisitor::visitArgument(Argument &A) {
|
||||
// no interprocedural analysis is done at the moment
|
||||
if (!A.hasByValAttr()) {
|
||||
++ObjectVisitorArgument;
|
||||
return unknown();
|
||||
}
|
||||
PointerType *PT = cast<PointerType>(A.getType());
|
||||
APInt Size(IntTyBits, TD->getTypeAllocSize(PT->getElementType()));
|
||||
return std::make_pair(align(Size, A.getParamAlignment()), Zero);
|
||||
}
|
||||
|
||||
SizeOffsetType ObjectSizeOffsetVisitor::visitCallSite(CallSite CS) {
|
||||
const AllocFnsTy *FnData = getAllocationData(CS.getInstruction(), AnyAlloc);
|
||||
if (!FnData)
|
||||
return unknown();
|
||||
|
||||
// handle strdup-like functions separately
|
||||
if (FnData->AllocTy == StrDupLike) {
|
||||
// TODO
|
||||
return unknown();
|
||||
}
|
||||
|
||||
ConstantInt *Arg = dyn_cast<ConstantInt>(CS.getArgument(FnData->FstParam));
|
||||
if (!Arg)
|
||||
return unknown();
|
||||
|
||||
APInt Size = Arg->getValue();
|
||||
// size determined by just 1 parameter
|
||||
if (FnData->SndParam == (unsigned char)-1)
|
||||
return std::make_pair(Size, Zero);
|
||||
|
||||
Arg = dyn_cast<ConstantInt>(CS.getArgument(FnData->SndParam));
|
||||
if (!Arg)
|
||||
return unknown();
|
||||
|
||||
Size *= Arg->getValue();
|
||||
return std::make_pair(Size, Zero);
|
||||
|
||||
// TODO: handle more standard functions (+ wchar cousins):
|
||||
// - strdup / strndup
|
||||
// - strcpy / strncpy
|
||||
// - strcat / strncat
|
||||
// - memcpy / memmove
|
||||
// - strcat / strncat
|
||||
// - memset
|
||||
}
|
||||
|
||||
SizeOffsetType
|
||||
ObjectSizeOffsetVisitor::visitConstantPointerNull(ConstantPointerNull&) {
|
||||
return std::make_pair(Zero, Zero);
|
||||
}
|
||||
|
||||
SizeOffsetType
|
||||
ObjectSizeOffsetVisitor::visitExtractValueInst(ExtractValueInst&) {
|
||||
// Easy cases were already folded by previous passes.
|
||||
return unknown();
|
||||
}
|
||||
|
||||
SizeOffsetType ObjectSizeOffsetVisitor::visitGEPOperator(GEPOperator &GEP) {
|
||||
SizeOffsetType PtrData = compute(GEP.getPointerOperand());
|
||||
if (!bothKnown(PtrData) || !GEP.hasAllConstantIndices())
|
||||
return unknown();
|
||||
|
||||
SmallVector<Value*, 8> Ops(GEP.idx_begin(), GEP.idx_end());
|
||||
APInt Offset(IntTyBits,TD->getIndexedOffset(GEP.getPointerOperandType(),Ops));
|
||||
return std::make_pair(PtrData.first, PtrData.second + Offset);
|
||||
}
|
||||
|
||||
SizeOffsetType ObjectSizeOffsetVisitor::visitGlobalVariable(GlobalVariable &GV){
|
||||
if (!GV.hasDefinitiveInitializer())
|
||||
return unknown();
|
||||
|
||||
APInt Size(IntTyBits, TD->getTypeAllocSize(GV.getType()->getElementType()));
|
||||
return std::make_pair(align(Size, GV.getAlignment()), Zero);
|
||||
}
|
||||
|
||||
SizeOffsetType ObjectSizeOffsetVisitor::visitIntToPtrInst(IntToPtrInst&) {
|
||||
// clueless
|
||||
return unknown();
|
||||
}
|
||||
|
||||
SizeOffsetType ObjectSizeOffsetVisitor::visitLoadInst(LoadInst&) {
|
||||
++ObjectVisitorLoad;
|
||||
return unknown();
|
||||
}
|
||||
|
||||
SizeOffsetType ObjectSizeOffsetVisitor::visitPHINode(PHINode&) {
|
||||
// too complex to analyze statically.
|
||||
return unknown();
|
||||
}
|
||||
|
||||
SizeOffsetType ObjectSizeOffsetVisitor::visitSelectInst(SelectInst &I) {
|
||||
SizeOffsetType TrueSide = compute(I.getTrueValue());
|
||||
SizeOffsetType FalseSide = compute(I.getFalseValue());
|
||||
if (bothKnown(TrueSide) && bothKnown(FalseSide) && TrueSide == FalseSide)
|
||||
return TrueSide;
|
||||
return unknown();
|
||||
}
|
||||
|
||||
SizeOffsetType ObjectSizeOffsetVisitor::visitUndefValue(UndefValue&) {
|
||||
return std::make_pair(Zero, Zero);
|
||||
}
|
||||
|
||||
SizeOffsetType ObjectSizeOffsetVisitor::visitInstruction(Instruction &I) {
|
||||
DEBUG(dbgs() << "ObjectSizeOffsetVisitor unknown instruction:" << I << '\n');
|
||||
return unknown();
|
||||
}
|
||||
|
||||
|
||||
ObjectSizeOffsetEvaluator::ObjectSizeOffsetEvaluator(const TargetData *TD,
|
||||
LLVMContext &Context)
|
||||
: TD(TD), Context(Context), Builder(Context, TargetFolder(TD)),
|
||||
Visitor(TD, Context) {
|
||||
IntTy = TD->getIntPtrType(Context);
|
||||
Zero = ConstantInt::get(IntTy, 0);
|
||||
}
|
||||
|
||||
SizeOffsetEvalType ObjectSizeOffsetEvaluator::compute(Value *V) {
|
||||
SizeOffsetEvalType Result = compute_(V);
|
||||
|
||||
if (!bothKnown(Result)) {
|
||||
// erase everything that was computed in this iteration from the cache, so
|
||||
// that no dangling references are left behind. We could be a bit smarter if
|
||||
// we kept a dependency graph. It's probably not worth the complexity.
|
||||
for (PtrSetTy::iterator I=SeenVals.begin(), E=SeenVals.end(); I != E; ++I) {
|
||||
CacheMapTy::iterator CacheIt = CacheMap.find(*I);
|
||||
// non-computable results can be safely cached
|
||||
if (CacheIt != CacheMap.end() && anyKnown(CacheIt->second))
|
||||
CacheMap.erase(CacheIt);
|
||||
}
|
||||
}
|
||||
|
||||
SeenVals.clear();
|
||||
return Result;
|
||||
}
|
||||
|
||||
SizeOffsetEvalType ObjectSizeOffsetEvaluator::compute_(Value *V) {
|
||||
SizeOffsetType Const = Visitor.compute(V);
|
||||
if (Visitor.bothKnown(Const))
|
||||
return std::make_pair(ConstantInt::get(Context, Const.first),
|
||||
ConstantInt::get(Context, Const.second));
|
||||
|
||||
V = V->stripPointerCasts();
|
||||
|
||||
// check cache
|
||||
CacheMapTy::iterator CacheIt = CacheMap.find(V);
|
||||
if (CacheIt != CacheMap.end())
|
||||
return CacheIt->second;
|
||||
|
||||
// always generate code immediately before the instruction being
|
||||
// processed, so that the generated code dominates the same BBs
|
||||
Instruction *PrevInsertPoint = Builder.GetInsertPoint();
|
||||
if (Instruction *I = dyn_cast<Instruction>(V))
|
||||
Builder.SetInsertPoint(I);
|
||||
|
||||
// record the pointers that were handled in this run, so that they can be
|
||||
// cleaned later if something fails
|
||||
SeenVals.insert(V);
|
||||
|
||||
// now compute the size and offset
|
||||
SizeOffsetEvalType Result;
|
||||
if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
|
||||
Result = visitGEPOperator(*GEP);
|
||||
} else if (Instruction *I = dyn_cast<Instruction>(V)) {
|
||||
Result = visit(*I);
|
||||
} else if (isa<Argument>(V) ||
|
||||
(isa<ConstantExpr>(V) &&
|
||||
cast<ConstantExpr>(V)->getOpcode() == Instruction::IntToPtr) ||
|
||||
isa<GlobalVariable>(V)) {
|
||||
// ignore values where we cannot do more than what ObjectSizeVisitor can
|
||||
Result = unknown();
|
||||
} else {
|
||||
DEBUG(dbgs() << "ObjectSizeOffsetEvaluator::compute() unhandled value: "
|
||||
<< *V << '\n');
|
||||
Result = unknown();
|
||||
}
|
||||
|
||||
if (PrevInsertPoint)
|
||||
Builder.SetInsertPoint(PrevInsertPoint);
|
||||
|
||||
// Don't reuse CacheIt since it may be invalid at this point.
|
||||
CacheMap[V] = Result;
|
||||
return Result;
|
||||
}
|
||||
|
||||
SizeOffsetEvalType ObjectSizeOffsetEvaluator::visitAllocaInst(AllocaInst &I) {
|
||||
if (!I.getAllocatedType()->isSized())
|
||||
return unknown();
|
||||
|
||||
// must be a VLA
|
||||
assert(I.isArrayAllocation());
|
||||
Value *ArraySize = I.getArraySize();
|
||||
Value *Size = ConstantInt::get(ArraySize->getType(),
|
||||
TD->getTypeAllocSize(I.getAllocatedType()));
|
||||
Size = Builder.CreateMul(Size, ArraySize);
|
||||
return std::make_pair(Size, Zero);
|
||||
}
|
||||
|
||||
SizeOffsetEvalType ObjectSizeOffsetEvaluator::visitCallSite(CallSite CS) {
|
||||
const AllocFnsTy *FnData = getAllocationData(CS.getInstruction(), AnyAlloc);
|
||||
if (!FnData)
|
||||
return unknown();
|
||||
|
||||
// handle strdup-like functions separately
|
||||
if (FnData->AllocTy == StrDupLike) {
|
||||
// TODO
|
||||
return unknown();
|
||||
}
|
||||
|
||||
Value *FirstArg = CS.getArgument(FnData->FstParam);
|
||||
if (FnData->SndParam == (unsigned char)-1)
|
||||
return std::make_pair(FirstArg, Zero);
|
||||
|
||||
Value *SecondArg = CS.getArgument(FnData->SndParam);
|
||||
Value *Size = Builder.CreateMul(FirstArg, SecondArg);
|
||||
return std::make_pair(Size, Zero);
|
||||
|
||||
// TODO: handle more standard functions (+ wchar cousins):
|
||||
// - strdup / strndup
|
||||
// - strcpy / strncpy
|
||||
// - strcat / strncat
|
||||
// - memcpy / memmove
|
||||
// - strcat / strncat
|
||||
// - memset
|
||||
}
|
||||
|
||||
SizeOffsetEvalType
|
||||
ObjectSizeOffsetEvaluator::visitGEPOperator(GEPOperator &GEP) {
|
||||
SizeOffsetEvalType PtrData = compute_(GEP.getPointerOperand());
|
||||
if (!bothKnown(PtrData))
|
||||
return unknown();
|
||||
|
||||
Value *Offset = EmitGEPOffset(&Builder, *TD, &GEP);
|
||||
Offset = Builder.CreateAdd(PtrData.second, Offset);
|
||||
return std::make_pair(PtrData.first, Offset);
|
||||
}
|
||||
|
||||
SizeOffsetEvalType ObjectSizeOffsetEvaluator::visitIntToPtrInst(IntToPtrInst&) {
|
||||
// clueless
|
||||
return unknown();
|
||||
}
|
||||
|
||||
SizeOffsetEvalType ObjectSizeOffsetEvaluator::visitLoadInst(LoadInst&) {
|
||||
return unknown();
|
||||
}
|
||||
|
||||
SizeOffsetEvalType ObjectSizeOffsetEvaluator::visitPHINode(PHINode &PHI) {
|
||||
// create 2 PHIs: one for size and another for offset
|
||||
PHINode *SizePHI = Builder.CreatePHI(IntTy, PHI.getNumIncomingValues());
|
||||
PHINode *OffsetPHI = Builder.CreatePHI(IntTy, PHI.getNumIncomingValues());
|
||||
|
||||
// insert right away in the cache to handle recursive PHIs
|
||||
CacheMap[&PHI] = std::make_pair(SizePHI, OffsetPHI);
|
||||
|
||||
// compute offset/size for each PHI incoming pointer
|
||||
for (unsigned i = 0, e = PHI.getNumIncomingValues(); i != e; ++i) {
|
||||
Builder.SetInsertPoint(PHI.getIncomingBlock(i)->getFirstInsertionPt());
|
||||
SizeOffsetEvalType EdgeData = compute_(PHI.getIncomingValue(i));
|
||||
|
||||
if (!bothKnown(EdgeData)) {
|
||||
OffsetPHI->replaceAllUsesWith(UndefValue::get(IntTy));
|
||||
OffsetPHI->eraseFromParent();
|
||||
SizePHI->replaceAllUsesWith(UndefValue::get(IntTy));
|
||||
SizePHI->eraseFromParent();
|
||||
return unknown();
|
||||
}
|
||||
SizePHI->addIncoming(EdgeData.first, PHI.getIncomingBlock(i));
|
||||
OffsetPHI->addIncoming(EdgeData.second, PHI.getIncomingBlock(i));
|
||||
}
|
||||
return std::make_pair(SizePHI, OffsetPHI);
|
||||
}
|
||||
|
||||
SizeOffsetEvalType ObjectSizeOffsetEvaluator::visitSelectInst(SelectInst &I) {
|
||||
SizeOffsetEvalType TrueSide = compute_(I.getTrueValue());
|
||||
SizeOffsetEvalType FalseSide = compute_(I.getFalseValue());
|
||||
|
||||
if (!bothKnown(TrueSide) || !bothKnown(FalseSide))
|
||||
return unknown();
|
||||
if (TrueSide == FalseSide)
|
||||
return TrueSide;
|
||||
|
||||
Value *Size = Builder.CreateSelect(I.getCondition(), TrueSide.first,
|
||||
FalseSide.first);
|
||||
Value *Offset = Builder.CreateSelect(I.getCondition(), TrueSide.second,
|
||||
FalseSide.second);
|
||||
return std::make_pair(Size, Offset);
|
||||
}
|
||||
|
||||
SizeOffsetEvalType ObjectSizeOffsetEvaluator::visitInstruction(Instruction &I) {
|
||||
DEBUG(dbgs() << "ObjectSizeOffsetEvaluator unknown instruction:" << I <<'\n');
|
||||
return unknown();
|
||||
}
|
||||
|
||||
@ -474,8 +474,7 @@ getPointerDependencyFrom(const AliasAnalysis::Location &MemLoc, bool isLoad,
|
||||
// a subsequent bitcast of the malloc call result. There can be stores to
|
||||
// the malloced memory between the malloc call and its bitcast uses, and we
|
||||
// need to continue scanning until the malloc call.
|
||||
if (isa<AllocaInst>(Inst) ||
|
||||
(isa<CallInst>(Inst) && extractMallocCall(Inst))) {
|
||||
if (isa<AllocaInst>(Inst) || isNoAliasFn(Inst)) {
|
||||
const Value *AccessPtr = GetUnderlyingObject(MemLoc.Ptr, TD);
|
||||
|
||||
if (AccessPtr == Inst || AA->isMustAlias(Inst, AccessPtr))
|
||||
|
||||
@ -172,7 +172,7 @@ Instruction *InstCombiner::SimplifyMemSet(MemSetInst *MI) {
|
||||
Instruction *InstCombiner::visitCallInst(CallInst &CI) {
|
||||
if (isFreeCall(&CI))
|
||||
return visitFree(CI);
|
||||
if (extractMallocCall(&CI) || extractCallocCall(&CI))
|
||||
if (isAllocLikeFn(&CI))
|
||||
return visitMalloc(CI);
|
||||
|
||||
// If the caller function is nounwind, mark the call as nounwind, even if the
|
||||
@ -246,84 +246,10 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
|
||||
switch (II->getIntrinsicID()) {
|
||||
default: break;
|
||||
case Intrinsic::objectsize: {
|
||||
// We need target data for just about everything so depend on it.
|
||||
if (!TD) return 0;
|
||||
|
||||
Type *ReturnTy = CI.getType();
|
||||
uint64_t DontKnow = II->getArgOperand(1) == Builder->getTrue() ? 0 : -1ULL;
|
||||
|
||||
// Get to the real allocated thing and offset as fast as possible.
|
||||
Value *Op1 = II->getArgOperand(0)->stripPointerCasts();
|
||||
|
||||
uint64_t Offset = 0;
|
||||
uint64_t Size = -1ULL;
|
||||
|
||||
// Try to look through constant GEPs.
|
||||
if (GEPOperator *GEP = dyn_cast<GEPOperator>(Op1)) {
|
||||
if (!GEP->hasAllConstantIndices()) return 0;
|
||||
|
||||
// Get the current byte offset into the thing. Use the original
|
||||
// operand in case we're looking through a bitcast.
|
||||
SmallVector<Value*, 8> Ops(GEP->idx_begin(), GEP->idx_end());
|
||||
if (!GEP->getPointerOperandType()->isPointerTy())
|
||||
return 0;
|
||||
Offset = TD->getIndexedOffset(GEP->getPointerOperandType(), Ops);
|
||||
|
||||
Op1 = GEP->getPointerOperand()->stripPointerCasts();
|
||||
|
||||
// Make sure we're not a constant offset from an external
|
||||
// global.
|
||||
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Op1))
|
||||
if (!GV->hasDefinitiveInitializer()) return 0;
|
||||
}
|
||||
|
||||
// If we've stripped down to a single global variable that we
|
||||
// can know the size of then just return that.
|
||||
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Op1)) {
|
||||
if (GV->hasDefinitiveInitializer()) {
|
||||
Constant *C = GV->getInitializer();
|
||||
Size = TD->getTypeAllocSize(C->getType());
|
||||
} else {
|
||||
// Can't determine size of the GV.
|
||||
Constant *RetVal = ConstantInt::get(ReturnTy, DontKnow);
|
||||
return ReplaceInstUsesWith(CI, RetVal);
|
||||
}
|
||||
} else if (AllocaInst *AI = dyn_cast<AllocaInst>(Op1)) {
|
||||
// Get alloca size.
|
||||
if (AI->getAllocatedType()->isSized()) {
|
||||
Size = TD->getTypeAllocSize(AI->getAllocatedType());
|
||||
if (AI->isArrayAllocation()) {
|
||||
const ConstantInt *C = dyn_cast<ConstantInt>(AI->getArraySize());
|
||||
if (!C) return 0;
|
||||
Size *= C->getZExtValue();
|
||||
}
|
||||
}
|
||||
} else if (CallInst *MI = extractMallocCall(Op1)) {
|
||||
// Get allocation size.
|
||||
Value *Arg = MI->getArgOperand(0);
|
||||
if (ConstantInt *CI = dyn_cast<ConstantInt>(Arg))
|
||||
Size = CI->getZExtValue();
|
||||
|
||||
} else if (CallInst *MI = extractCallocCall(Op1)) {
|
||||
// Get allocation size.
|
||||
Value *Arg1 = MI->getArgOperand(0);
|
||||
Value *Arg2 = MI->getArgOperand(1);
|
||||
if (ConstantInt *CI1 = dyn_cast<ConstantInt>(Arg1))
|
||||
if (ConstantInt *CI2 = dyn_cast<ConstantInt>(Arg2))
|
||||
Size = (CI1->getValue() * CI2->getValue()).getZExtValue();
|
||||
}
|
||||
|
||||
// Do not return "I don't know" here. Later optimization passes could
|
||||
// make it possible to evaluate objectsize to a constant.
|
||||
if (Size == -1ULL)
|
||||
return 0;
|
||||
|
||||
if (Size < Offset) {
|
||||
// Out of bound reference? Negative index normalized to large
|
||||
// index? Just return "I don't know".
|
||||
return ReplaceInstUsesWith(CI, ConstantInt::get(ReturnTy, DontKnow));
|
||||
}
|
||||
return ReplaceInstUsesWith(CI, ConstantInt::get(ReturnTy, Size-Offset));
|
||||
uint64_t Size;
|
||||
if (getObjectSize(II->getArgOperand(0), Size, TD))
|
||||
return ReplaceInstUsesWith(CI, ConstantInt::get(CI.getType(), Size));
|
||||
return 0;
|
||||
}
|
||||
case Intrinsic::bswap:
|
||||
// bswap(bswap(x)) -> x
|
||||
@ -768,7 +694,7 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
|
||||
TerminatorInst *TI = II->getParent()->getTerminator();
|
||||
bool CannotRemove = false;
|
||||
for (++BI; &*BI != TI; ++BI) {
|
||||
if (isa<AllocaInst>(BI) || isMalloc(BI)) {
|
||||
if (isa<AllocaInst>(BI)) {
|
||||
CannotRemove = true;
|
||||
break;
|
||||
}
|
||||
|
||||
@ -1068,7 +1068,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
|
||||
// If the bitcast is of an allocation, and the allocation will be
|
||||
// converted to match the type of the cast, don't touch this.
|
||||
if (isa<AllocaInst>(BCI->getOperand(0)) ||
|
||||
isMalloc(BCI->getOperand(0))) {
|
||||
isAllocationFn(BCI->getOperand(0))) {
|
||||
// See if the bitcast simplifies, if so, don't nuke this GEP yet.
|
||||
if (Instruction *I = visitBitCast(*BCI)) {
|
||||
if (I != BCI) {
|
||||
|
||||
@ -275,39 +275,9 @@ static Value *getStoredPointerOperand(Instruction *I) {
|
||||
}
|
||||
|
||||
static uint64_t getPointerSize(const Value *V, AliasAnalysis &AA) {
|
||||
const TargetData *TD = AA.getTargetData();
|
||||
|
||||
if (const CallInst *CI = extractMallocCall(V)) {
|
||||
if (const ConstantInt *C = dyn_cast<ConstantInt>(CI->getArgOperand(0)))
|
||||
return C->getZExtValue();
|
||||
}
|
||||
|
||||
if (const CallInst *CI = extractCallocCall(V)) {
|
||||
if (const ConstantInt *C1 = dyn_cast<ConstantInt>(CI->getArgOperand(0)))
|
||||
if (const ConstantInt *C2 = dyn_cast<ConstantInt>(CI->getArgOperand(1)))
|
||||
return (C1->getValue() * C2->getValue()).getZExtValue();
|
||||
}
|
||||
|
||||
if (TD == 0)
|
||||
return AliasAnalysis::UnknownSize;
|
||||
|
||||
if (const AllocaInst *A = dyn_cast<AllocaInst>(V)) {
|
||||
// Get size information for the alloca
|
||||
if (const ConstantInt *C = dyn_cast<ConstantInt>(A->getArraySize()))
|
||||
return C->getZExtValue() * TD->getTypeAllocSize(A->getAllocatedType());
|
||||
}
|
||||
|
||||
if (const Argument *A = dyn_cast<Argument>(V)) {
|
||||
if (A->hasByValAttr())
|
||||
if (PointerType *PT = dyn_cast<PointerType>(A->getType()))
|
||||
return TD->getTypeAllocSize(PT->getElementType());
|
||||
}
|
||||
|
||||
if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
|
||||
if (!GV->mayBeOverridden())
|
||||
return TD->getTypeAllocSize(GV->getType()->getElementType());
|
||||
}
|
||||
|
||||
uint64_t Size;
|
||||
if (getObjectSize(V, Size, AA.getTargetData()))
|
||||
return Size;
|
||||
return AliasAnalysis::UnknownSize;
|
||||
}
|
||||
|
||||
@ -705,16 +675,13 @@ bool DSE::handleEndBlock(BasicBlock &BB) {
|
||||
// Find all of the alloca'd pointers in the entry block.
|
||||
BasicBlock *Entry = BB.getParent()->begin();
|
||||
for (BasicBlock::iterator I = Entry->begin(), E = Entry->end(); I != E; ++I) {
|
||||
if (AllocaInst *AI = dyn_cast<AllocaInst>(I))
|
||||
DeadStackObjects.insert(AI);
|
||||
if (isa<AllocaInst>(I))
|
||||
DeadStackObjects.insert(I);
|
||||
|
||||
// Okay, so these are dead heap objects, but if the pointer never escapes
|
||||
// then it's leaked by this function anyways.
|
||||
CallInst *CI = extractMallocCall(I);
|
||||
if (!CI)
|
||||
CI = extractCallocCall(I);
|
||||
if (CI && !PointerMayBeCaptured(CI, true, true))
|
||||
DeadStackObjects.insert(CI);
|
||||
else if (isAllocLikeFn(I) && !PointerMayBeCaptured(I, true, true))
|
||||
DeadStackObjects.insert(I);
|
||||
}
|
||||
|
||||
// Treat byval arguments the same, stores to them are dead at the end of the
|
||||
@ -773,18 +740,8 @@ bool DSE::handleEndBlock(BasicBlock &BB) {
|
||||
continue;
|
||||
}
|
||||
|
||||
if (AllocaInst *A = dyn_cast<AllocaInst>(BBI)) {
|
||||
DeadStackObjects.remove(A);
|
||||
continue;
|
||||
}
|
||||
|
||||
if (CallInst *CI = extractMallocCall(BBI)) {
|
||||
DeadStackObjects.remove(CI);
|
||||
continue;
|
||||
}
|
||||
|
||||
if (CallInst *CI = extractCallocCall(BBI)) {
|
||||
DeadStackObjects.remove(CI);
|
||||
if (isa<AllocaInst>(BBI) || isAllocLikeFn(BBI)) {
|
||||
DeadStackObjects.remove(BBI);
|
||||
continue;
|
||||
}
|
||||
|
||||
|
||||
@ -1436,7 +1436,7 @@ bool GVN::processNonLocalLoad(LoadInst *LI) {
|
||||
Instruction *DepInst = DepInfo.getInst();
|
||||
|
||||
// Loading the allocation -> undef.
|
||||
if (isa<AllocaInst>(DepInst) || isMalloc(DepInst) ||
|
||||
if (isa<AllocaInst>(DepInst) || isMallocLikeFn(DepInst) ||
|
||||
// Loading immediately after lifetime begin -> undef.
|
||||
isLifetimeStart(DepInst)) {
|
||||
ValuesPerBlock.push_back(AvailableValueInBlock::get(DepBB,
|
||||
@ -1951,7 +1951,7 @@ bool GVN::processLoad(LoadInst *L) {
|
||||
// If this load really doesn't depend on anything, then we must be loading an
|
||||
// undef value. This can happen when loading for a fresh allocation with no
|
||||
// intervening stores, for example.
|
||||
if (isa<AllocaInst>(DepInst) || isMalloc(DepInst)) {
|
||||
if (isa<AllocaInst>(DepInst) || isMallocLikeFn(DepInst)) {
|
||||
L->replaceAllUsesWith(UndefValue::get(L->getType()));
|
||||
markInstructionForDeletion(L);
|
||||
++NumGVNLoad;
|
||||
|
||||
@ -266,7 +266,7 @@ bool llvm::isInstructionTriviallyDead(Instruction *I) {
|
||||
return isa<UndefValue>(II->getArgOperand(1));
|
||||
}
|
||||
|
||||
if (extractMallocCall(I) || extractCallocCall(I)) return true;
|
||||
if (isAllocLikeFn(I)) return true;
|
||||
|
||||
if (CallInst *CI = isFreeCall(I))
|
||||
if (Constant *C = dyn_cast<Constant>(CI->getArgOperand(0)))
|
||||
|
||||
@ -42,7 +42,7 @@ define i32 @f() nounwind {
|
||||
|
||||
define i1 @baz() nounwind {
|
||||
; CHECK: @baz
|
||||
; CHECK-NEXT: ret i1 true
|
||||
; CHECK-NEXT: objectsize
|
||||
%1 = tail call i32 @llvm.objectsize.i32(i8* getelementptr inbounds ([0 x i8]* @window, i32 0, i32 0), i1 false)
|
||||
%2 = icmp eq i32 %1, -1
|
||||
ret i1 %2
|
||||
|
||||
Loading…
Reference in New Issue
Block a user