Changes in directory llvm/lib/CodeGen/SelectionDAG:
DAGCombiner.cpp updated: 1.144 -> 1.145
---
Log message:
1. If both vector operands of a vector_shuffle are undef, turn it into an undef.
2. A shuffle mask element can also be an undef.
---
Diffs of the changes: (+6 -3)
DAGCombiner.cpp | 9 ++++++---
1 files changed, 6 insertions(+), 3 deletions(-)
Index: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
diff -u llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:1.144
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:1.145
--- llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:1.144 Tue Apr 4 12:39:18 2006
+++ llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Thu Apr 6 18:20:43 2006
@@ -2673,16 +2673,19 @@
// If the LHS and the RHS are the same node, turn the RHS into an undef.
if (N->getOperand(0) == N->getOperand(1)) {
+ if (N->getOperand(0).getOpcode() == ISD::UNDEF)
+ return DAG.getNode(ISD::UNDEF, N->getValueType(0));
// Check the SHUFFLE mask, mapping any inputs from the 2nd operand into the
// first operand.
std::vector<SDOperand> MappedOps;
for (unsigned i = 0, e = ShufMask.getNumOperands(); i != e; ++i) {
- if (cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() >= NumElts)
{
+ if (ShufMask.getOperand(i).getOpcode() == ISD::UNDEF ||
+ cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() < NumElts) {
+ MappedOps.push_back(ShufMask.getOperand(i));
+ } else {
unsigned NewIdx =
cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() - NumElts;
MappedOps.push_back(DAG.getConstant(NewIdx, MVT::i32));
- } else {
- MappedOps.push_back(ShufMask.getOperand(i));
}
}
ShufMask = DAG.getNode(ISD::BUILD_VECTOR, ShufMask.getValueType(),
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