Fix optimization of ISD::TRUNCATE on vector operands. Based on a patch
by Micah Villmow for PR6335.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97461 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 2762ce8..eca9f3f 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1441,8 +1441,10 @@
case ISD::TRUNCATE: {
// Simplify the input, using demanded bit information, and compute the known
// zero/one bits live out.
+ unsigned OperandBitWidth =
+ Op.getOperand(0).getValueType().getScalarType().getSizeInBits();
APInt TruncMask = NewMask;
- TruncMask.zext(Op.getOperand(0).getValueSizeInBits());
+ TruncMask.zext(OperandBitWidth);
if (SimplifyDemandedBits(Op.getOperand(0), TruncMask,
KnownZero, KnownOne, TLO, Depth+1))
return true;
@@ -1453,15 +1455,14 @@
// on the known demanded bits.
if (Op.getOperand(0).getNode()->hasOneUse()) {
SDValue In = Op.getOperand(0);
- unsigned InBitWidth = In.getValueSizeInBits();
switch (In.getOpcode()) {
default: break;
case ISD::SRL:
// Shrink SRL by a constant if none of the high bits shifted in are
// demanded.
if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(In.getOperand(1))){
- APInt HighBits = APInt::getHighBitsSet(InBitWidth,
- InBitWidth - BitWidth);
+ APInt HighBits = APInt::getHighBitsSet(OperandBitWidth,
+ OperandBitWidth - BitWidth);
HighBits = HighBits.lshr(ShAmt->getZExtValue());
HighBits.trunc(BitWidth);