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[SSE2] Minor tidyup of v16i8 SHL lowering. NFC.

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Removed code that was replicating v8i16 'shift + mask' implementation that is done more nicely by making use of LowerScalarImmediateShift


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236388 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Simon Pilgrim 2015-05-02 14:42:43 +00:00
parent d85813d9a5
commit 6b7b96f74c
1 changed files with 5 additions and 16 deletions
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21
lib/Target/X86/X86ISelLowering.cpp
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@ -16688,24 +16688,15 @@ static SDValue LowerShift(SDValue Op, const X86Subtarget* Subtarget,
}
if (VT == MVT::v16i8 && Op->getOpcode() == ISD::SHL) {
assert(Subtarget->hasSSE2() && "Need SSE2 for pslli/pcmpeq.");
// a = a << 5;
// Turn 'a' into a mask suitable for VSELECT: a = a << 5;
Op = DAG.getNode(ISD::SHL, dl, VT, Amt, DAG.getConstant(5, dl, VT));
Op = DAG.getNode(ISD::BITCAST, dl, VT, Op);
// Turn 'a' into a mask suitable for VSELECT
SDValue VSelM = DAG.getConstant(0x80, dl, VT);
SDValue OpVSel = DAG.getNode(ISD::AND, dl, VT, VSelM, Op);
OpVSel = DAG.getNode(X86ISD::PCMPEQ, dl, VT, OpVSel, VSelM);
SDValue CM1 = DAG.getConstant(0x0f, dl, VT);
SDValue CM2 = DAG.getConstant(0x3f, dl, VT);
// r = VSELECT(r, psllw(r & (char16)15, 4), a);
SDValue M = DAG.getNode(ISD::AND, dl, VT, R, CM1);
M = getTargetVShiftByConstNode(X86ISD::VSHLI, dl, MVT::v8i16, M, 4, DAG);
M = DAG.getNode(ISD::BITCAST, dl, VT, M);
// r = VSELECT(r, shl(r, 4), a);
SDValue M = DAG.getNode(ISD::SHL, dl, VT, R, DAG.getConstant(4, dl, VT));
R = DAG.getNode(ISD::VSELECT, dl, VT, OpVSel, M, R);
// a += a
@ -16713,10 +16704,8 @@ static SDValue LowerShift(SDValue Op, const X86Subtarget* Subtarget,
OpVSel = DAG.getNode(ISD::AND, dl, VT, VSelM, Op);
OpVSel = DAG.getNode(X86ISD::PCMPEQ, dl, VT, OpVSel, VSelM);
// r = VSELECT(r, psllw(r & (char16)63, 2), a);
M = DAG.getNode(ISD::AND, dl, VT, R, CM2);
M = getTargetVShiftByConstNode(X86ISD::VSHLI, dl, MVT::v8i16, M, 2, DAG);
M = DAG.getNode(ISD::BITCAST, dl, VT, M);
// r = VSELECT(r, shl(r, 2), a);
M = DAG.getNode(ISD::SHL, dl, VT, R, DAG.getConstant(2, dl, VT));
R = DAG.getNode(ISD::VSELECT, dl, VT, OpVSel, M, R);
// a += a