- SDValue Tmp1 = getTargetVShiftNode(X86ISD::VSHLI, dl, VT,
- Op.getOperand(0), ShAmt, DAG);
+ // (sext (vzext x)) -> (vsext x)
+ SDValue Op0 = Op.getOperand(0);
+ SDValue Op00 = Op0.getOperand(0);
+ SDValue Tmp1;
+ // Hopefully, this VECTOR_SHUFFLE is just a VZEXT.
+ if (Op0.getOpcode() == ISD::BITCAST &&
+ Op00.getOpcode() == ISD::VECTOR_SHUFFLE)
+ Tmp1 = LowerVectorIntExtend(Op00, DAG);
+ if (Tmp1.getNode()) {
+ SDValue Tmp1Op0 = Tmp1.getOperand(0);
+ assert(Tmp1Op0.getOpcode() == X86ISD::VZEXT &&
+ "This optimization is invalid without a VZEXT.");
+ return DAG.getNode(X86ISD::VSEXT, dl, VT, Tmp1Op0.getOperand(0));
+ }
+
+ // If the above didn't work, then just use Shift-Left + Shift-Right.
+ Tmp1 = getTargetVShiftNode(X86ISD::VSHLI, dl, VT, Op0, ShAmt, DAG);