Teach SimplifyDemandedBits how to look through fpext and fptrunc to simplify their operand
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160823 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index 125c74a..46ba83b 100644
--- a/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -1074,6 +1074,12 @@
// like undef&0. The result is known zero, not undef.
UndefElts &= UndefElts2;
break;
+ case Instruction::FPTrunc:
+ case Instruction::FPExt:
+ TmpV = SimplifyDemandedVectorElts(I->getOperand(0), DemandedElts,
+ UndefElts, Depth+1);
+ if (TmpV) { I->setOperand(0, TmpV); MadeChange = true; }
+ break;
case Instruction::Call: {
IntrinsicInst *II = dyn_cast<IntrinsicInst>(I);