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Do not fold (add (shl x, c1), (shl c2, c1)) -> (shl (add x, c2), c1), 

we want to canonicalize the other way.

llvm-svn: 26547
This commit is contained in:
Chris Lattner 2006-03-05 19:52:57 +00:00
parent c610e62e46
commit c726a5c31f
1 changed files with 0 additions and 18 deletions
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18
llvm/lib/Target/TargetLowering.cpp
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@ -580,24 +580,6 @@ bool TargetLowering::SimplifyDemandedBits(SDOperand Op, uint64_t DemandedMask,
CountTrailingZeros_64(~KnownZero2));
KnownZero = (1ULL << KnownZeroOut) - 1;
KnownOne = 0;
SDOperand SH = Op.getOperand(0);
// fold (add (shl x, c1), (shl c2, c1)) -> (shl (add x, c2), c1)
if (KnownZero && SH.getOpcode() == ISD::SHL && SH.Val->hasOneUse() &&
Op.Val->hasOneUse()) {
if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(SH.getOperand(1))) {
MVT::ValueType VT = Op.getValueType();
unsigned ShiftAmt = SA->getValue();
uint64_t AddAmt = AA->getValue();
uint64_t AddShr = AddAmt >> ShiftAmt;
if (AddAmt == (AddShr << ShiftAmt)) {
SDOperand ADD = TLO.DAG.getNode(ISD::ADD, VT, SH.getOperand(0),
TLO.DAG.getConstant(AddShr, VT));
SDOperand SHL = TLO.DAG.getNode(ISD::SHL, VT, ADD,SH.getOperand(1));
return TLO.CombineTo(Op, SHL);
}
}
}
}
break;
case ISD::SUB: