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Make promoteOp work for CT*

Proof?

ubyte %bar(ubyte %x) {
entry:
        %tmp.1 = call ubyte %llvm.ctlz( ubyte %x )
        ret ubyte %tmp.1
}

==>

zapnot $16,1,$0
CTLZ $0,$0
subq $0,56,$0
zapnot $0,1,$0
ret $31,($26),1

llvm-svn: 21691
This commit is contained in:
Andrew Lenharth 2005-05-04 19:11:05 +00:00
parent 1c462db06f
commit 9282d00d4f

View File

@ -1534,6 +1534,34 @@ SDOperand SelectionDAGLegalize::PromoteOp(SDOperand Op) {
AddLegalizedOperand(Op.getValue(1), Result.getValue(1));
break;
}
case ISD::CTPOP:
case ISD::CTTZ:
case ISD::CTLZ:
Tmp1 = Node->getOperand(0);
//Zero extend the argument
Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, NVT, Tmp1);
// Perform the larger operation, then subtract if needed.
Tmp1 = DAG.getNode(Node->getOpcode(), NVT, Tmp1);
switch(Node->getOpcode())
{
case ISD::CTPOP:
Result = Tmp1;
break;
case ISD::CTTZ:
//if Tmp1 == sizeinbits(NVT) then Tmp1 = sizeinbits(Old VT)
Tmp2 = DAG.getSetCC(ISD::SETEQ, MVT::i1, Tmp1,
DAG.getConstant(getSizeInBits(NVT), NVT));
Result = DAG.getNode(ISD::SELECT, NVT, Tmp2,
DAG.getConstant(getSizeInBits(VT),NVT), Tmp1);
break;
case ISD::CTLZ:
//Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT))
Result = DAG.getNode(ISD::SUB, NVT, Tmp1,
DAG.getConstant(getSizeInBits(NVT) -
getSizeInBits(VT), NVT));
break;
}
break;
}
assert(Result.Val && "Didn't set a result!");