fix PR6940: sitofp(undef) folds to 0.0, not undef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102358 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SCCP.cpp b/lib/Transforms/Scalar/SCCP.cpp
index 59cdee6..907ece8 100644
--- a/lib/Transforms/Scalar/SCCP.cpp
+++ b/lib/Transforms/Scalar/SCCP.cpp
@@ -1452,6 +1452,8 @@
// After a zero extend, we know the top part is zero. SExt doesn't have
// to be handled here, because we don't know whether the top part is 1's
// or 0's.
+ case Instruction::SIToFP: // some FP values are not possible, just use 0.
+ case Instruction::UIToFP: // some FP values are not possible, just use 0.
markForcedConstant(I, Constant::getNullValue(ITy));
return true;
case Instruction::Mul: