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Fold (zext (and x, cst)) -> (and (zext x), cst).

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91380 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng
2009-12-15 00:52:11 +00:00
parent 9682043ab5
commit 8acb3100de
2 changed files with 17 additions and 4 deletions
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13
lib/CodeGen/SelectionDAG/DAGCombiner.cpp
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@@ -3202,6 +3202,19 @@ SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
X, DAG.getConstant(Mask, VT));
}
// Fold (zext (and x, cst)) -> (and (zext x), cst)
if (N0.getOpcode() == ISD::AND &&
N0.getOperand(1).getOpcode() == ISD::Constant &&
N0.getOperand(0).getOpcode() != ISD::TRUNCATE &&
N0.getOperand(0).hasOneUse()) {
APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
Mask.zext(VT.getSizeInBits());
return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT,
N0.getOperand(0)),
DAG.getConstant(Mask, VT));
}
// fold (zext (load x)) -> (zext (truncate (zextload x)))
if (ISD::isNON_EXTLoad(N0.getNode()) &&
((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||