return DAG.getBuildVector(VT, dl, ULTOp1);
}
+/// As another special case, use PSUBUS[BW] when it's profitable. E.g. for
+/// Op0 u<= Op1:
+/// t = psubus Op0, Op1
+/// pcmpeq t, <0..0>
+static SDValue LowerVSETCCWithSUBUS(SDValue Op0, SDValue Op1, MVT VT,
+ ISD::CondCode Cond, const SDLoc &dl,
+ const X86Subtarget &Subtarget,
+ SelectionDAG &DAG) {
+ if (!Subtarget.hasSSE2())
+ return SDValue();
+
+ MVT VET = VT.getVectorElementType();
+ if (VET != MVT::i8 && VET != MVT::i16)
+ return SDValue();
+
+ switch (Cond) {
+ default:
+ return SDValue();
+ case ISD::SETULT: {
+ // If the comparison is against a constant we can turn this into a
+ // setule. With psubus, setule does not require a swap. This is
+ // beneficial because the constant in the register is no longer
+ // destructed as the destination so it can be hoisted out of a loop.
+ // Only do this pre-AVX since vpcmp* is no longer destructive.
+ if (Subtarget.hasAVX())
+ return SDValue();
+ SDValue ULEOp1 = ChangeVSETULTtoVSETULE(dl, Op1, DAG);
+ if (!ULEOp1)
+ return SDValue();
+ Op1 = ULEOp1;
+ break;
+ }
+ // Psubus is better than flip-sign because it requires no inversion.
+ case ISD::SETUGE:
+ std::swap(Op0, Op1);
+ break;
+ case ISD::SETULE:
+ break;
+ }
+
+ SDValue Result = DAG.getNode(X86ISD::SUBUS, dl, VT, Op0, Op1);
+ return DAG.getNode(X86ISD::PCMPEQ, dl, VT, Result,
+ getZeroVector(VT, Subtarget, DAG, dl));
+}
+
static SDValue LowerVSETCC(SDValue Op, const X86Subtarget &Subtarget,
SelectionDAG &DAG) {
SDValue Op0 = Op.getOperand(0);
return Result;
}
+ // Try to use SUBUS and PCMPEQ.
+ if (SDValue V = LowerVSETCCWithSUBUS(Op0, Op1, VT, Cond, dl, Subtarget, DAG))
+ return V;
+
// We are handling one of the integer comparisons here. Since SSE only has
// GT and EQ comparisons for integer, swapping operands and multiple
// operations may be required for some comparisons.
bool Invert = Cond == ISD::SETNE ||
(Cond != ISD::SETEQ && ISD::isTrueWhenEqual(Cond));
- MVT VET = VT.getVectorElementType();
- bool HasSubus = Subtarget.hasSSE2() && (VET == MVT::i8 || VET == MVT::i16);
- bool Subus = false;
- if (HasSubus) {
- // As another special case, use PSUBUS[BW] when it's profitable. E.g. for
- // Op0 u<= Op1:
- // t = psubus Op0, Op1
- // pcmpeq t, <0..0>
- switch (Cond) {
- default: break;
- case ISD::SETULT: {
- // If the comparison is against a constant we can turn this into a
- // setule. With psubus, setule does not require a swap. This is
- // beneficial because the constant in the register is no longer
- // destructed as the destination so it can be hoisted out of a loop.
- // Only do this pre-AVX since vpcmp* is no longer destructive.
- if (Subtarget.hasAVX())
- break;
- if (SDValue ULEOp1 = ChangeVSETULTtoVSETULE(dl, Op1, DAG)) {
- Op1 = ULEOp1;
- Subus = true; Invert = false; Swap = false;
- }
- break;
- }
- // Psubus is better than flip-sign because it requires no inversion.
- case ISD::SETUGE: Subus = true; Invert = false; Swap = true; break;
- case ISD::SETULE: Subus = true; Invert = false; Swap = false; break;
- }
-
- if (Subus) {
- Opc = X86ISD::SUBUS;
- FlipSigns = false;
- }
- }
-
if (Swap)
std::swap(Op0, Op1);
if (Invert)
Result = DAG.getNOT(dl, Result, VT);
- if (Subus)
- Result = DAG.getNode(X86ISD::PCMPEQ, dl, VT, Result,
- getZeroVector(VT, Subtarget, DAG, dl));
-
return Result;
}