diff options
Diffstat (limited to 'llvm/lib/Analysis/LoopAccessAnalysis.cpp')
| -rw-r--r-- | llvm/lib/Analysis/LoopAccessAnalysis.cpp | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp index a0df64b..ff5bc59 100644 --- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp +++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp @@ -467,7 +467,7 @@ public: /// (i.e. the pointers have computable bounds). bool canCheckPtrAtRT(RuntimePointerChecking &RtCheck, ScalarEvolution *SE, Loop *TheLoop, const ValueToValueMap &Strides, - bool ShouldCheckStride = false); + bool ShouldCheckWrap = false); /// \brief Goes over all memory accesses, checks whether a RT check is needed /// and builds sets of dependent accesses. @@ -551,10 +551,21 @@ static bool hasComputableBounds(PredicatedScalarEvolution &PSE, return AR->isAffine(); } +/// \brief Check whether a pointer address cannot wrap. +static bool isNoWrap(PredicatedScalarEvolution &PSE, + const ValueToValueMap &Strides, Value *Ptr, Loop *L) { + const SCEV *PtrScev = PSE.getSCEV(Ptr); + if (PSE.getSE()->isLoopInvariant(PtrScev, L)) + return true; + + int Stride = getPtrStride(PSE, Ptr, L, Strides); + return Stride == 1; +} + bool AccessAnalysis::canCheckPtrAtRT(RuntimePointerChecking &RtCheck, ScalarEvolution *SE, Loop *TheLoop, const ValueToValueMap &StridesMap, - bool ShouldCheckStride) { + bool ShouldCheckWrap) { // Find pointers with computable bounds. We are going to use this information // to place a runtime bound check. bool CanDoRT = true; @@ -589,8 +600,7 @@ bool AccessAnalysis::canCheckPtrAtRT(RuntimePointerChecking &RtCheck, if (hasComputableBounds(PSE, StridesMap, Ptr, TheLoop) && // When we run after a failing dependency check we have to make sure // we don't have wrapping pointers. - (!ShouldCheckStride || - getPtrStride(PSE, Ptr, TheLoop, StridesMap) == 1)) { + (!ShouldCheckWrap || isNoWrap(PSE, StridesMap, Ptr, TheLoop))) { // The id of the dependence set. unsigned DepId; |