Fix OptimizeMax to handle an odd case where one of the max operands
is another max which folds. This fixes PR7454.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106594 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index d14d7d9..e8da89a 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -1643,8 +1643,11 @@
NewRHS = Sel->getOperand(1);
else if (SE.getSCEV(Sel->getOperand(2)) == MaxRHS)
NewRHS = Sel->getOperand(2);
+ else if (const SCEVUnknown *SU = dyn_cast<SCEVUnknown>(MaxRHS))
+ NewRHS = SU->getValue();
else
- llvm_unreachable("Max doesn't match expected pattern!");
+ // Max doesn't match expected pattern.
+ return Cond;
// Determine the new comparison opcode. It may be signed or unsigned,
// and the original comparison may be either equality or inequality.