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[SelectionDAG] Teach LegalizeVectorOps to not unroll CTLZ_ZERO_UNDEF and CTTZ_ZERO_UNDEF if the non-ZERO_UNDEF form is legal or custom. Will be used to simplify X86 code in a follow on commit.

llvm-svn: 256476
This commit is contained in:
Craig Topper 2015-12-27 21:33:47 +00:00
parent ce5014e9fe
commit ec0fd66634

View File

@ -106,6 +106,7 @@ class VectorLegalizer {
SDValue ExpandStore(SDValue Op);
SDValue ExpandFNEG(SDValue Op);
SDValue ExpandBITREVERSE(SDValue Op);
SDValue ExpandCTLZ_CTTZ_ZERO_UNDEF(SDValue Op);
/// \brief Implements vector promotion.
///
@ -719,6 +720,9 @@ SDValue VectorLegalizer::Expand(SDValue Op) {
return UnrollVSETCC(Op);
case ISD::BITREVERSE:
return ExpandBITREVERSE(Op);
case ISD::CTLZ_ZERO_UNDEF:
case ISD::CTTZ_ZERO_UNDEF:
return ExpandCTLZ_CTTZ_ZERO_UNDEF(Op);
default:
return DAG.UnrollVectorOp(Op.getNode());
}
@ -1022,6 +1026,16 @@ SDValue VectorLegalizer::ExpandFNEG(SDValue Op) {
return DAG.UnrollVectorOp(Op.getNode());
}
SDValue VectorLegalizer::ExpandCTLZ_CTTZ_ZERO_UNDEF(SDValue Op) {
// If the non-ZERO_UNDEF version is supported we can let LegalizeDAG handle.
unsigned Opc = Op.getOpcode() == ISD::CTLZ_ZERO_UNDEF ? ISD::CTLZ : ISD::CTTZ;
if (TLI.isOperationLegalOrCustom(Opc, Op.getValueType()))
return Op;
// Otherwise go ahead and unroll.
return DAG.UnrollVectorOp(Op.getNode());
}
SDValue VectorLegalizer::UnrollVSETCC(SDValue Op) {
EVT VT = Op.getValueType();
unsigned NumElems = VT.getVectorNumElements();