diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Analysis/InstructionSimplify.cpp | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index 9b0ce11..37253f7 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -1522,13 +1522,27 @@ static Value *ExtractEquivalentCondition(Value *V, CmpInst::Predicate Pred, /// stripPointerAdjustments - This is like Value::stripPointerCasts, but also /// removes inbounds gep operations, regardless of their indices. +static Value *stripPointerAdjustmentsImpl(Value *V, + SmallPtrSet<GEPOperator*, 8> &VisitedGEPs) { + GEPOperator *GEP = dyn_cast<GEPOperator>(V); + if (GEP == 0 || !GEP->isInBounds()) + return V; + + // If we've already seen this GEP, we will end up infinitely looping. This + // can happen in unreachable code. + if (!VisitedGEPs.insert(GEP)) + return V; + + return stripPointerAdjustmentsImpl(GEP->getOperand(0)->stripPointerCasts(), + VisitedGEPs); +} + static Value *stripPointerAdjustments(Value *V) { - if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) - if (GEP->isInBounds()) - return stripPointerAdjustments(GEP->getOperand(0)->stripPointerCasts()); - return V; + SmallPtrSet<GEPOperator*, 8> VisitedGEPs; + return stripPointerAdjustmentsImpl(V, VisitedGEPs); } + /// SimplifyICmpInst - Given operands for an ICmpInst, see if we can /// fold the result. If not, this returns null. static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, |