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| author | Hal Finkel <hfinkel@anl.gov> | 2016-07-11 01:32:20 +0000 |
|---|---|---|
| committer | Hal Finkel <hfinkel@anl.gov> | 2016-07-11 01:32:20 +0000 |
| commit | 5c12d8fe8f7ac9a3ec13ddad1561d63477e014f6 (patch) | |
| tree | dd44cb608cfc199b1e9db70058b537669b386dcb /llvm/lib/Analysis/BasicAliasAnalysis.cpp | |
| parent | 47646c09818bd3571d72b3f0e312b1f301ec66ee (diff) | |
| download | llvm-5c12d8fe8f7ac9a3ec13ddad1561d63477e014f6.zip llvm-5c12d8fe8f7ac9a3ec13ddad1561d63477e014f6.tar.gz llvm-5c12d8fe8f7ac9a3ec13ddad1561d63477e014f6.tar.bz2 | |
BasicAA should look through functions with returned arguments
Motivated by the work on the llvm.noalias intrinsic, teach BasicAA to look
through returned-argument functions when answering queries. This is essential
so that we don't loose all other AA information when supplementing with
llvm.noalias.
Differential Revision: http://reviews.llvm.org/D9383
llvm-svn: 275035
Diffstat (limited to 'llvm/lib/Analysis/BasicAliasAnalysis.cpp')
| -rw-r--r-- | llvm/lib/Analysis/BasicAliasAnalysis.cpp | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/llvm/lib/Analysis/BasicAliasAnalysis.cpp b/llvm/lib/Analysis/BasicAliasAnalysis.cpp index 7efcd724..43d5c3cc 100644 --- a/llvm/lib/Analysis/BasicAliasAnalysis.cpp +++ b/llvm/lib/Analysis/BasicAliasAnalysis.cpp @@ -376,6 +376,12 @@ bool BasicAAResult::DecomposeGEPExpression(const Value *V, const GEPOperator *GEPOp = dyn_cast<GEPOperator>(Op); if (!GEPOp) { + if (auto CS = ImmutableCallSite(V)) + if (const Value *RV = CS.getReturnedArgOperand()) { + V = RV; + continue; + } + // If it's not a GEP, hand it off to SimplifyInstruction to see if it // can come up with something. This matches what GetUnderlyingObject does. if (const Instruction *I = dyn_cast<Instruction>(V)) @@ -817,7 +823,10 @@ static AliasResult aliasSameBasePointerGEPs(const GEPOperator *GEP1, uint64_t V2Size, const DataLayout &DL) { - assert(GEP1->getPointerOperand() == GEP2->getPointerOperand() && + assert(GEP1->getPointerOperand()->stripPointerCasts() == + GEP2->getPointerOperand()->stripPointerCasts() && + GEP1->getPointerOperand()->getType() == + GEP2->getPointerOperand()->getType() && "Expected GEPs with the same pointer operand"); // Try to determine whether GEP1 and GEP2 index through arrays, into structs, @@ -1075,7 +1084,10 @@ AliasResult BasicAAResult::aliasGEP(const GEPOperator *GEP1, uint64_t V1Size, // If we know the two GEPs are based off of the exact same pointer (and not // just the same underlying object), see if that tells us anything about // the resulting pointers. - if (GEP1->getPointerOperand() == GEP2->getPointerOperand()) { + if (GEP1->getPointerOperand()->stripPointerCasts() == + GEP2->getPointerOperand()->stripPointerCasts() && + GEP1->getPointerOperand()->getType() == + GEP2->getPointerOperand()->getType()) { AliasResult R = aliasSameBasePointerGEPs(GEP1, V1Size, GEP2, V2Size, DL); // If we couldn't find anything interesting, don't abandon just yet. if (R != MayAlias) |