return DAG.getVectorShuffle(VT, SDLoc(SVN), S0, S1, SVN->getMask());
}
+static SDValue simplifyShuffleMask(ShuffleVectorSDNode *SVN, SDValue N0,
+ SDValue N1, SelectionDAG &DAG) {
+ // TODO - handle cases other than BUILD_VECTOR.
+ auto *BV0 = dyn_cast<BuildVectorSDNode>(N0);
+ auto *BV1 = dyn_cast<BuildVectorSDNode>(N1);
+ if (!BV0 && !BV1)
+ return SDValue();
+
+ EVT VT = SVN->getValueType(0);
+ unsigned NumElts = VT.getVectorNumElements();
+
+ bool Changed = false;
+ SmallVector<int, 8> NewMask;
+ for (unsigned i = 0; i != NumElts; ++i) {
+ int Idx = SVN->getMaskElt(i);
+ if (BV0 && 0 <= Idx && Idx < (int)NumElts &&
+ BV0->getOperand(Idx).isUndef()) {
+ Changed = true;
+ Idx = -1;
+ } else if (BV1 && Idx > (int)NumElts &&
+ BV1->getOperand(Idx - NumElts).isUndef()) {
+ Changed = true;
+ Idx = -1;
+ }
+ NewMask.push_back(Idx);
+ }
+ if (Changed)
+ return DAG.getVectorShuffle(VT, SDLoc(SVN), N0, N1, NewMask);
+
+ return SDValue();
+}
+
// Tries to turn a shuffle of two CONCAT_VECTORS into a single concat,
// or turn a shuffle of a single concat into simpler shuffle then concat.
static SDValue partitionShuffleOfConcats(SDNode *N, SelectionDAG &DAG) {
return DAG.getVectorShuffle(VT, SDLoc(N), N0, N1, NewMask);
}
+ // Simplify shuffle mask if a referenced element is UNDEF.
+ if (SDValue V = simplifyShuffleMask(SVN, N0, N1, DAG))
+ return V;
+
// A shuffle of a single vector that is a splat can always be folded.
if (auto *N0Shuf = dyn_cast<ShuffleVectorSDNode>(N0))
if (N1->isUndef() && N0Shuf->isSplat())
; X32-LABEL: broadcast_shuffle_1000:
; X32: ## BB#0:
; X32-NEXT: movl {{[0-9]+}}(%esp), %eax
-; X32-NEXT: vmovddup {{.*#+}} xmm0 = mem[0,0]
-; X32-NEXT: vinsertf128 $1, %xmm0, %ymm0, %ymm0
+; X32-NEXT: vbroadcastsd (%eax), %ymm0
; X32-NEXT: retl
;
; X64-LABEL: broadcast_shuffle_1000:
; X64: ## BB#0:
-; X64-NEXT: vmovddup {{.*#+}} xmm0 = mem[0,0]
-; X64-NEXT: vinsertf128 $1, %xmm0, %ymm0, %ymm0
+; X64-NEXT: vbroadcastsd (%rdi), %ymm0
; X64-NEXT: retq
%1 = load double, double* %p
%2 = insertelement <2 x double> undef, double %1, i32 0
; X32-LABEL: broadcast_shuffle1032:
; X32: ## BB#0:
; X32-NEXT: movl {{[0-9]+}}(%esp), %eax
-; X32-NEXT: vmovsd {{.*#+}} xmm0 = mem[0],zero
-; X32-NEXT: vmovddup {{.*#+}} xmm1 = xmm0[0,0]
-; X32-NEXT: vinsertf128 $1, %xmm0, %ymm1, %ymm0
-; X32-NEXT: vpermilpd {{.*#+}} ymm0 = ymm0[1,0,3,2]
+; X32-NEXT: vmovddup {{.*#+}} xmm0 = mem[0,0]
+; X32-NEXT: vinsertf128 $1, %xmm0, %ymm0, %ymm0
; X32-NEXT: retl
;
; X64-LABEL: broadcast_shuffle1032:
; X64: ## BB#0:
-; X64-NEXT: vmovsd {{.*#+}} xmm0 = mem[0],zero
-; X64-NEXT: vmovddup {{.*#+}} xmm1 = xmm0[0,0]
-; X64-NEXT: vinsertf128 $1, %xmm0, %ymm1, %ymm0
-; X64-NEXT: vpermilpd {{.*#+}} ymm0 = ymm0[1,0,3,2]
+; X64-NEXT: vmovddup {{.*#+}} xmm0 = mem[0,0]
+; X64-NEXT: vinsertf128 $1, %xmm0, %ymm0, %ymm0
; X64-NEXT: retq
%1 = load double, double* %p
%2 = insertelement <2 x double> undef, double %1, i32 1