Permit ChangeCompareStride to rewrite a comparison when the factor
between the comparison's iv stride and the candidate stride is
exactly -1.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70244 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index c436cec..a6795a7 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -2028,7 +2028,9 @@
if (!isa<SCEVConstant>(SI->first))
continue;
int64_t SSInt = cast<SCEVConstant>(SI->first)->getValue()->getSExtValue();
- if (abs(SSInt) <= abs(CmpSSInt) || (SSInt % CmpSSInt) != 0)
+ if (SSInt == CmpSSInt ||
+ abs(SSInt) < abs(CmpSSInt) ||
+ (SSInt % CmpSSInt) != 0)
continue;
Scale = SSInt / CmpSSInt;