[LoopUnrollAnalyzer] Fix a crash in analyzeLoopUnrollCost.
Condition might be simplified to a Constant, but it doesn't have to be
ConstantInt, so we should dyn_cast, instead of cast.
This fixes PR27886.
llvm-svn: 270924
diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
index 8e65af9..b3f138c 100644
--- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -464,41 +464,37 @@
// Add in the live successors by first checking whether we have terminator
// that may be simplified based on the values simplified by this call.
+ BasicBlock *KnownSucc = nullptr;
if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
if (BI->isConditional()) {
if (Constant *SimpleCond =
SimplifiedValues.lookup(BI->getCondition())) {
- BasicBlock *Succ = nullptr;
// Just take the first successor if condition is undef
if (isa<UndefValue>(SimpleCond))
- Succ = BI->getSuccessor(0);
- else
- Succ = BI->getSuccessor(
- cast<ConstantInt>(SimpleCond)->isZero() ? 1 : 0);
- if (L->contains(Succ))
- BBWorklist.insert(Succ);
- else
- ExitWorklist.insert({BB, Succ});
- continue;
+ KnownSucc = BI->getSuccessor(0);
+ else if (ConstantInt *SimpleCondVal =
+ dyn_cast<ConstantInt>(SimpleCond))
+ KnownSucc = BI->getSuccessor(SimpleCondVal->isZero() ? 1 : 0);
}
}
} else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
if (Constant *SimpleCond =
SimplifiedValues.lookup(SI->getCondition())) {
- BasicBlock *Succ = nullptr;
// Just take the first successor if condition is undef
if (isa<UndefValue>(SimpleCond))
- Succ = SI->getSuccessor(0);
- else
- Succ = SI->findCaseValue(cast<ConstantInt>(SimpleCond))
- .getCaseSuccessor();
- if (L->contains(Succ))
- BBWorklist.insert(Succ);
- else
- ExitWorklist.insert({BB, Succ});
- continue;
+ KnownSucc = SI->getSuccessor(0);
+ else if (ConstantInt *SimpleCondVal =
+ dyn_cast<ConstantInt>(SimpleCond))
+ KnownSucc = SI->findCaseValue(SimpleCondVal).getCaseSuccessor();
}
}
+ if (KnownSucc) {
+ if (L->contains(KnownSucc))
+ BBWorklist.insert(KnownSucc);
+ else
+ ExitWorklist.insert({BB, KnownSucc});
+ continue;
+ }
// Add BB's successors to the worklist.
for (BasicBlock *Succ : successors(BB))