Improve constant folding of undef for cmp and select operators.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134223 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index 9d78f8b..8709f6b 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -2204,15 +2204,15 @@
if (TrueVal == FalseVal)
return TrueVal;
- if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X
- return FalseVal;
- if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
- return TrueVal;
if (isa<UndefValue>(CondVal)) { // select undef, X, Y -> X or Y
if (isa<Constant>(TrueVal))
return TrueVal;
return FalseVal;
}
+ if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X
+ return FalseVal;
+ if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
+ return TrueVal;
return 0;
}