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| author | Stephen Hines <srhines@google.com> | 2013-01-21 13:15:17 -0800 |
|---|---|---|
| committer | Stephen Hines <srhines@google.com> | 2013-01-21 13:15:17 -0800 |
| commit | 059800f9e3fee2852672f846d91a2da14da7783a (patch) | |
| tree | a6ef16b7263252ae1b8069295ea9cbbae0d9467d /lib/Analysis/BasicAliasAnalysis.cpp | |
| parent | cbefa15de4821975bb99fc6d74b3bdb42b2df45c (diff) | |
| parent | b6714227eda5d499f7667fc865f931126a8dc488 (diff) | |
| download | external_llvm-059800f9e3fee2852672f846d91a2da14da7783a.zip external_llvm-059800f9e3fee2852672f846d91a2da14da7783a.tar.gz external_llvm-059800f9e3fee2852672f846d91a2da14da7783a.tar.bz2 | |
Merge remote-tracking branch 'upstream/master' into merge-llvm
Conflicts:
lib/CodeGen/AsmPrinter/AsmPrinter.cpp
lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
lib/MC/MCAssembler.cpp
lib/Support/Atomic.cpp
lib/Support/Memory.cpp
lib/Target/ARM/ARMJITInfo.cpp
Change-Id: Ib339baf88df5b04870c8df1bedcfe1f877ccab8d
Diffstat (limited to 'lib/Analysis/BasicAliasAnalysis.cpp')
| -rw-r--r-- | lib/Analysis/BasicAliasAnalysis.cpp | 116 |
1 files changed, 50 insertions, 66 deletions
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp index a3bc06a..ca668b2 100644 --- a/lib/Analysis/BasicAliasAnalysis.cpp +++ b/lib/Analysis/BasicAliasAnalysis.cpp @@ -13,28 +13,28 @@ // //===----------------------------------------------------------------------===// -#include "llvm/Analysis/AliasAnalysis.h" #include "llvm/Analysis/Passes.h" -#include "llvm/Constants.h" -#include "llvm/DerivedTypes.h" -#include "llvm/Function.h" -#include "llvm/GlobalAlias.h" -#include "llvm/GlobalVariable.h" -#include "llvm/Instructions.h" -#include "llvm/IntrinsicInst.h" -#include "llvm/LLVMContext.h" -#include "llvm/Operator.h" -#include "llvm/Pass.h" +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/Analysis/AliasAnalysis.h" #include "llvm/Analysis/CaptureTracking.h" -#include "llvm/Analysis/MemoryBuiltins.h" #include "llvm/Analysis/InstructionSimplify.h" +#include "llvm/Analysis/MemoryBuiltins.h" #include "llvm/Analysis/ValueTracking.h" -#include "llvm/Target/TargetData.h" -#include "llvm/Target/TargetLibraryInfo.h" -#include "llvm/ADT/SmallPtrSet.h" -#include "llvm/ADT/SmallVector.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/DerivedTypes.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/GlobalAlias.h" +#include "llvm/IR/GlobalVariable.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/IntrinsicInst.h" +#include "llvm/IR/LLVMContext.h" +#include "llvm/IR/Operator.h" +#include "llvm/Pass.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/GetElementPtrTypeIterator.h" +#include "llvm/Target/TargetLibraryInfo.h" #include <algorithm> using namespace llvm; @@ -58,12 +58,12 @@ static bool isNonEscapingLocalObject(const Value *V) { // then it has not escaped before entering the function. Check if it escapes // inside the function. if (const Argument *A = dyn_cast<Argument>(V)) - if (A->hasByValAttr() || A->hasNoAliasAttr()) { - // Don't bother analyzing arguments already known not to escape. - if (A->hasNoCaptureAttr()) - return true; + if (A->hasByValAttr() || A->hasNoAliasAttr()) + // Note even if the argument is marked nocapture we still need to check + // for copies made inside the function. The nocapture attribute only + // specifies that there are no copies made that outlive the function. return !PointerMayBeCaptured(V, false, /*StoreCaptures=*/true); - } + return false; } @@ -84,7 +84,7 @@ static bool isEscapeSource(const Value *V) { /// getObjectSize - Return the size of the object specified by V, or /// UnknownSize if unknown. -static uint64_t getObjectSize(const Value *V, const TargetData &TD, +static uint64_t getObjectSize(const Value *V, const DataLayout &TD, const TargetLibraryInfo &TLI, bool RoundToAlign = false) { uint64_t Size; @@ -96,7 +96,7 @@ static uint64_t getObjectSize(const Value *V, const TargetData &TD, /// isObjectSmallerThan - Return true if we can prove that the object specified /// by V is smaller than Size. static bool isObjectSmallerThan(const Value *V, uint64_t Size, - const TargetData &TD, + const DataLayout &TD, const TargetLibraryInfo &TLI) { // This function needs to use the aligned object size because we allow // reads a bit past the end given sufficient alignment. @@ -108,7 +108,7 @@ static bool isObjectSmallerThan(const Value *V, uint64_t Size, /// isObjectSize - Return true if we can prove that the object specified /// by V has size Size. static bool isObjectSize(const Value *V, uint64_t Size, - const TargetData &TD, const TargetLibraryInfo &TLI) { + const DataLayout &TD, const TargetLibraryInfo &TLI) { uint64_t ObjectSize = getObjectSize(V, TD, TLI); return ObjectSize != AliasAnalysis::UnknownSize && ObjectSize == Size; } @@ -151,7 +151,7 @@ namespace { /// represented in the result. static Value *GetLinearExpression(Value *V, APInt &Scale, APInt &Offset, ExtensionKind &Extension, - const TargetData &TD, unsigned Depth) { + const DataLayout &TD, unsigned Depth) { assert(V->getType()->isIntegerTy() && "Not an integer value"); // Limit our recursion depth. @@ -226,14 +226,14 @@ static Value *GetLinearExpression(Value *V, APInt &Scale, APInt &Offset, /// specified amount, but which may have other unrepresented high bits. As such, /// the gep cannot necessarily be reconstructed from its decomposed form. /// -/// When TargetData is around, this function is capable of analyzing everything +/// When DataLayout is around, this function is capable of analyzing everything /// that GetUnderlyingObject can look through. When not, it just looks /// through pointer casts. /// static const Value * DecomposeGEPExpression(const Value *V, int64_t &BaseOffs, SmallVectorImpl<VariableGEPIndex> &VarIndices, - const TargetData *TD) { + const DataLayout *TD) { // Limit recursion depth to limit compile time in crazy cases. unsigned MaxLookup = 6; @@ -277,7 +277,7 @@ DecomposeGEPExpression(const Value *V, int64_t &BaseOffs, ->getElementType()->isSized()) return V; - // If we are lacking TargetData information, we can't compute the offets of + // If we are lacking DataLayout information, we can't compute the offets of // elements computed by GEPs. However, we can handle bitcast equivalent // GEPs. if (TD == 0) { @@ -631,7 +631,7 @@ BasicAliasAnalysis::getModRefBehavior(const Function *F) { // For intrinsics, we can check the table. if (unsigned iid = F->getIntrinsicID()) { #define GET_INTRINSIC_MODREF_BEHAVIOR -#include "llvm/Intrinsics.gen" +#include "llvm/IR/Intrinsics.gen" #undef GET_INTRINSIC_MODREF_BEHAVIOR } @@ -868,7 +868,7 @@ BasicAliasAnalysis::aliasGEP(const GEPOperator *GEP1, uint64_t V1Size, const Value *GEP1BasePtr = DecomposeGEPExpression(GEP1, GEP1BaseOffset, GEP1VariableIndices, TD); // DecomposeGEPExpression and GetUnderlyingObject should return the - // same result except when DecomposeGEPExpression has no TargetData. + // same result except when DecomposeGEPExpression has no DataLayout. if (GEP1BasePtr != UnderlyingV1 || GEP2BasePtr != UnderlyingV2) { assert(TD == 0 && "DecomposeGEPExpression and GetUnderlyingObject disagree!"); @@ -902,7 +902,7 @@ BasicAliasAnalysis::aliasGEP(const GEPOperator *GEP1, uint64_t V1Size, DecomposeGEPExpression(GEP2, GEP2BaseOffset, GEP2VariableIndices, TD); // DecomposeGEPExpression and GetUnderlyingObject should return the - // same result except when DecomposeGEPExpression has no TargetData. + // same result except when DecomposeGEPExpression has no DataLayout. if (GEP1BasePtr != UnderlyingV1 || GEP2BasePtr != UnderlyingV2) { assert(TD == 0 && "DecomposeGEPExpression and GetUnderlyingObject disagree!"); @@ -937,7 +937,7 @@ BasicAliasAnalysis::aliasGEP(const GEPOperator *GEP1, uint64_t V1Size, DecomposeGEPExpression(GEP1, GEP1BaseOffset, GEP1VariableIndices, TD); // DecomposeGEPExpression and GetUnderlyingObject should return the - // same result except when DecomposeGEPExpression has no TargetData. + // same result except when DecomposeGEPExpression has no DataLayout. if (GEP1BasePtr != UnderlyingV1) { assert(TD == 0 && "DecomposeGEPExpression and GetUnderlyingObject disagree!"); @@ -1064,39 +1064,20 @@ BasicAliasAnalysis::aliasPHI(const PHINode *PN, uint64_t PNSize, Location(V2, V2Size, V2TBAAInfo)); if (PN > V2) std::swap(Locs.first, Locs.second); - - AliasResult Alias = - aliasCheck(PN->getIncomingValue(0), PNSize, PNTBAAInfo, - PN2->getIncomingValueForBlock(PN->getIncomingBlock(0)), - V2Size, V2TBAAInfo); - if (Alias == MayAlias) - return MayAlias; - - // If the first source of the PHI nodes NoAlias and the other inputs are - // the PHI node itself through some amount of recursion this does not add - // any new information so just return NoAlias. - // bb: - // ptr = ptr2 + 1 - // loop: - // ptr_phi = phi [bb, ptr], [loop, ptr_plus_one] - // ptr2_phi = phi [bb, ptr2], [loop, ptr2_plus_one] - // ... - // ptr_plus_one = gep ptr_phi, 1 - // ptr2_plus_one = gep ptr2_phi, 1 - // We assume for the recursion that the the phis (ptr_phi, ptr2_phi) do - // not alias each other. - bool ArePhisAssumedNoAlias = false; - AliasResult OrigAliasResult; - if (Alias == NoAlias) { - // Pretend the phis do not alias. - assert(AliasCache.count(Locs) && - "There must exist an entry for the phi node"); - OrigAliasResult = AliasCache[Locs]; - AliasCache[Locs] = NoAlias; - ArePhisAssumedNoAlias = true; - } - - for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i) { + // Analyse the PHIs' inputs under the assumption that the PHIs are + // NoAlias. + // If the PHIs are May/MustAlias there must be (recursively) an input + // operand from outside the PHIs' cycle that is MayAlias/MustAlias or + // there must be an operation on the PHIs within the PHIs' value cycle + // that causes a MayAlias. + // Pretend the phis do not alias. + AliasResult Alias = NoAlias; + assert(AliasCache.count(Locs) && + "There must exist an entry for the phi node"); + AliasResult OrigAliasResult = AliasCache[Locs]; + AliasCache[Locs] = NoAlias; + + for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { AliasResult ThisAlias = aliasCheck(PN->getIncomingValue(i), PNSize, PNTBAAInfo, PN2->getIncomingValueForBlock(PN->getIncomingBlock(i)), @@ -1107,7 +1088,7 @@ BasicAliasAnalysis::aliasPHI(const PHINode *PN, uint64_t PNSize, } // Reset if speculation failed. - if (ArePhisAssumedNoAlias && Alias != NoAlias) + if (Alias != NoAlias) AliasCache[Locs] = OrigAliasResult; return Alias; @@ -1245,6 +1226,7 @@ BasicAliasAnalysis::aliasCheck(const Value *V1, uint64_t V1Size, std::swap(V1, V2); std::swap(V1Size, V2Size); std::swap(O1, O2); + std::swap(V1TBAAInfo, V2TBAAInfo); } if (const GEPOperator *GV1 = dyn_cast<GEPOperator>(V1)) { AliasResult Result = aliasGEP(GV1, V1Size, V1TBAAInfo, V2, V2Size, V2TBAAInfo, O1, O2); @@ -1254,6 +1236,7 @@ BasicAliasAnalysis::aliasCheck(const Value *V1, uint64_t V1Size, if (isa<PHINode>(V2) && !isa<PHINode>(V1)) { std::swap(V1, V2); std::swap(V1Size, V2Size); + std::swap(V1TBAAInfo, V2TBAAInfo); } if (const PHINode *PN = dyn_cast<PHINode>(V1)) { AliasResult Result = aliasPHI(PN, V1Size, V1TBAAInfo, @@ -1264,6 +1247,7 @@ BasicAliasAnalysis::aliasCheck(const Value *V1, uint64_t V1Size, if (isa<SelectInst>(V2) && !isa<SelectInst>(V1)) { std::swap(V1, V2); std::swap(V1Size, V2Size); + std::swap(V1TBAAInfo, V2TBAAInfo); } if (const SelectInst *S1 = dyn_cast<SelectInst>(V1)) { AliasResult Result = aliasSelect(S1, V1Size, V1TBAAInfo, |
