diff options
| -rw-r--r-- | llvm/lib/Analysis/ScalarEvolution.cpp | 27 |
1 files changed, 5 insertions, 22 deletions
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index 038204e8839..401e736396d 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -61,6 +61,7 @@ #include "llvm/Analysis/ScalarEvolution.h" #include "llvm/ADT/Optional.h" #include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/ScopeExit.h" #include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/Statistic.h" #include "llvm/Analysis/AssumptionCache.h" @@ -8058,34 +8059,16 @@ ScalarEvolution::isLoopEntryGuardedByCond(const Loop *L, return false; } -namespace { -/// RAII wrapper to prevent recursive application of isImpliedCond. -/// ScalarEvolution's PendingLoopPredicates set must be empty unless we are -/// currently evaluating isImpliedCond. -struct MarkPendingLoopPredicate { - Value *Cond; - SmallPtrSetImpl<Value *> &LoopPreds; - bool Pending; - - MarkPendingLoopPredicate(Value *C, SmallPtrSetImpl<Value *> &LP) - : Cond(C), LoopPreds(LP) { - Pending = !LoopPreds.insert(Cond).second; - } - ~MarkPendingLoopPredicate() { - if (!Pending) - LoopPreds.erase(Cond); - } -}; -} // end anonymous namespace - bool ScalarEvolution::isImpliedCond(ICmpInst::Predicate Pred, const SCEV *LHS, const SCEV *RHS, Value *FoundCondValue, bool Inverse) { - MarkPendingLoopPredicate Mark(FoundCondValue, PendingLoopPredicates); - if (Mark.Pending) + if (!PendingLoopPredicates.insert(FoundCondValue).second) return false; + auto ClearOnExit = + make_scope_exit([&]() { PendingLoopPredicates.erase(FoundCondValue); }); + // Recursively handle And and Or conditions. if (BinaryOperator *BO = dyn_cast<BinaryOperator>(FoundCondValue)) { if (BO->getOpcode() == Instruction::And) { |
