Just mark the sign bit as known zero, rather than any other irrelevant bits
known zero in the LHS. Fixes PR12541.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155818 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index a430f62..1418e01 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -564,7 +564,7 @@
Depth+1);
// If it's known zero, our sign bit is also zero.
if (LHSKnownZero.isNegative())
- KnownZero |= LHSKnownZero;
+ KnownZero.setBit(BitWidth - 1);
}
break;