}
}
+/// \brief Try to lower a vector shuffle as a 128-bit shuffles.
+static SDValue lowerV4X128VectorShuffle(SDLoc DL, MVT VT,
+ ArrayRef<int> Mask,
+ SDValue V1, SDValue V2,
+ SelectionDAG &DAG) {
+ assert(VT.getScalarSizeInBits() == 64 &&
+ "Unexpected element type size for 128bit shuffle.");
+
+ // To handle 256 bit vector requires VLX and most probably
+ // function lowerV2X128VectorShuffle() is better solution.
+ assert(VT.getSizeInBits() == 512 &&
+ "Unexpected vector size for 128bit shuffle.");
+
+ SmallVector<int, 4> WidenedMask;
+ if (!canWidenShuffleElements(Mask, WidenedMask))
+ return SDValue();
+
+ // Form a 128-bit permutation.
+ // Convert the 64-bit shuffle mask selection values into 128-bit selection
+ // bits defined by a vshuf64x2 instruction's immediate control byte.
+ unsigned PermMask = 0, Imm = 0;
+ unsigned ControlBitsNum = WidenedMask.size() / 2;
+
+ for (int i = 0, Size = WidenedMask.size(); i < Size; ++i) {
+ if (WidenedMask[i] == SM_SentinelZero)
+ return SDValue();
+
+ // Use first element in place of undef mask.
+ Imm = (WidenedMask[i] == SM_SentinelUndef) ? 0 : WidenedMask[i];
+ PermMask |= (Imm % WidenedMask.size()) << (i * ControlBitsNum);
+ }
+
+ return DAG.getNode(X86ISD::SHUF128, DL, VT, V1, V2,
+ DAG.getConstant(PermMask, DL, MVT::i8));
+}
+
static SDValue lowerVectorShuffleWithPERMV(SDLoc DL, MVT VT,
ArrayRef<int> Mask, SDValue V1,
SDValue V2, SelectionDAG &DAG) {
ArrayRef<int> Mask = SVOp->getMask();
assert(Mask.size() == 8 && "Unexpected mask size for v8 shuffle!");
+ if (SDValue Shuf128 =
+ lowerV4X128VectorShuffle(DL, MVT::v8f64, Mask, V1, V2, DAG))
+ return Shuf128;
+
if (SDValue Unpck =
lowerVectorShuffleWithUNPCK(DL, MVT::v8f64, Mask, V1, V2, DAG))
return Unpck;
ArrayRef<int> Mask = SVOp->getMask();
assert(Mask.size() == 8 && "Unexpected mask size for v8 shuffle!");
+ if (SDValue Shuf128 =
+ lowerV4X128VectorShuffle(DL, MVT::v8i64, Mask, V1, V2, DAG))
+ return Shuf128;
+
if (SDValue Unpck =
lowerVectorShuffleWithUNPCK(DL, MVT::v8i64, Mask, V1, V2, DAG))
return Unpck;