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Redo previous patch so optimization only done for i1. 

Simpler and safer.

llvm-svn: 44663
This commit is contained in:
Dale Johannesen 2007-12-06 17:53:31 +00:00
parent 6b644a6e05
commit 5eff4de9c8
1 changed files with 4 additions and 16 deletions
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20
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
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@ -2455,10 +2455,6 @@ SDOperand DAGCombiner::visitSELECT(SDNode *N) {
MVT::ValueType VT = N->getValueType(0);
MVT::ValueType VT0 = N0.getValueType();
// Some targets have SETCC types bigger than 1 bit, but do not set all the
// bits to 1; identified by getSetCCResultContents. Watch out for these.
// fold select C, X, X -> X
if (N1 == N2)
return N1;
@ -2483,22 +2479,14 @@ SDOperand DAGCombiner::visitSELECT(SDNode *N) {
return DAG.getNode(ISD::TRUNCATE, VT, XORNode);
}
// fold select C, 0, X -> ~C & X
if (VT == VT0 && N1C && N1C->isNullValue() &&
(N0.Val->getOpcode()!=ISD::SETCC || VT==MVT::i1 ||
TLI.getSetCCResultContents()==
TargetLowering::ZeroOrNegativeOneSetCCResult)) {
SDOperand XORNode;
XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(~0UL, VT));
if (VT == VT0 && VT == MVT::i1 && N1C && N1C->isNullValue()) {
SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
AddToWorkList(XORNode.Val);
return DAG.getNode(ISD::AND, VT, XORNode, N2);
}
// fold select C, X, 1 -> ~C | X
if (VT == VT0 && N2C && N2C->getValue() == 1 &&
(N0.Val->getOpcode()!=ISD::SETCC || VT==MVT::i1 ||
TLI.getSetCCResultContents()==
TargetLowering::ZeroOrNegativeOneSetCCResult)) {
SDOperand XORNode;
XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(~0UL, VT));
if (VT == VT0 && VT == MVT::i1 && N2C && N2C->getValue() == 1) {
SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
AddToWorkList(XORNode.Val);
return DAG.getNode(ISD::OR, VT, XORNode, N1);
}