ShuffleVectorInst::commuteShuffleMask(Indices, InVecNumElts);
}
+ // A splat of an inserted scalar constant becomes a vector constant:
+ // shuf (inselt ?, C, IndexC), undef, <IndexC, IndexC...> --> <C, C...>
+ // NOTE: We may have commuted above, so analyze the updated Indices, not the
+ // original mask constant.
+ Constant *C;
+ ConstantInt *IndexC;
+ if (match(Op0, m_InsertElement(m_Value(), m_Constant(C),
+ m_ConstantInt(IndexC)))) {
+ // Match a splat shuffle mask of the insert index allowing undef elements.
+ int InsertIndex = IndexC->getZExtValue();
+ if (all_of(Indices, [InsertIndex](int MaskElt) {
+ return MaskElt == InsertIndex || MaskElt == -1;
+ })) {
+ assert(isa<UndefValue>(Op1) && "Expected undef operand 1 for splat");
+
+ // Shuffle mask undefs become undefined constant result elements.
+ SmallVector<Constant *, 16> VecC(MaskNumElts, C);
+ for (unsigned i = 0; i != MaskNumElts; ++i)
+ if (Indices[i] == -1)
+ VecC[i] = UndefValue::get(C->getType());
+ return ConstantVector::get(VecC);
+ }
+ }
+
// A shuffle of a splat is always the splat itself. Legal if the shuffle's
// value type is same as the input vectors' type.
if (auto *OpShuf = dyn_cast<ShuffleVectorInst>(Op0))
define <4 x float> @splat_constant(<4 x float> %x) {
; CHECK-LABEL: @splat_constant(
; CHECK-NEXT: [[INS3:%.*]] = insertelement <4 x float> [[X:%.*]], float 3.000000e+00, i32 3
-; CHECK-NEXT: [[SPLAT3:%.*]] = shufflevector <4 x float> [[INS3]], <4 x float> undef, <4 x i32> <i32 3, i32 3, i32 3, i32 3>
-; CHECK-NEXT: [[R:%.*]] = fadd <4 x float> [[INS3]], [[SPLAT3]]
+; CHECK-NEXT: [[R:%.*]] = fadd <4 x float> [[INS3]], <float 3.000000e+00, float 3.000000e+00, float 3.000000e+00, float 3.000000e+00>
; CHECK-NEXT: ret <4 x float> [[R]]
;
%ins3 = insertelement <4 x float> %x, float 3.0, i32 3
define <5 x i8> @splat_inserted_constant(<4 x i8> %x) {
; CHECK-LABEL: @splat_inserted_constant(
-; CHECK-NEXT: [[INS3:%.*]] = insertelement <4 x i8> [[X:%.*]], i8 42, i64 3
-; CHECK-NEXT: [[SPLAT5:%.*]] = shufflevector <4 x i8> [[INS3]], <4 x i8> undef, <5 x i32> <i32 3, i32 3, i32 3, i32 3, i32 3>
-; CHECK-NEXT: ret <5 x i8> [[SPLAT5]]
+; CHECK-NEXT: ret <5 x i8> <i8 42, i8 42, i8 42, i8 42, i8 42>
;
%ins3 = insertelement <4 x i8> %x, i8 42, i64 3
%splat5 = shufflevector <4 x i8> %ins3, <4 x i8> undef, <5 x i32> <i32 3, i32 3, i32 3, i32 3, i32 3>
define <4 x float> @splat_inserted_constant_undef_elt(<4 x float> %x) {
; CHECK-LABEL: @splat_inserted_constant_undef_elt(
-; CHECK-NEXT: [[INS1:%.*]] = insertelement <4 x float> [[X:%.*]], float 1.200000e+01, i32 1
-; CHECK-NEXT: [[SPLAT1:%.*]] = shufflevector <4 x float> [[INS1]], <4 x float> undef, <4 x i32> <i32 1, i32 1, i32 undef, i32 1>
-; CHECK-NEXT: ret <4 x float> [[SPLAT1]]
+; CHECK-NEXT: ret <4 x float> <float 1.200000e+01, float 1.200000e+01, float undef, float 1.200000e+01>
;
%ins1 = insertelement <4 x float> %x, float 12.0, i32 1
%splat1 = shufflevector <4 x float> %ins1, <4 x float> undef, <4 x i32> <i32 1, i32 1, i32 undef, i32 1>
define <2 x i8> @splat_inserted_constant_not_canonical(<3 x i8> %x, <3 x i8> %y) {
; CHECK-LABEL: @splat_inserted_constant_not_canonical(
-; CHECK-NEXT: [[INS2:%.*]] = insertelement <3 x i8> [[X:%.*]], i8 23, i7 2
-; CHECK-NEXT: [[SPLAT2:%.*]] = shufflevector <3 x i8> [[Y:%.*]], <3 x i8> [[INS2]], <2 x i32> <i32 undef, i32 5>
-; CHECK-NEXT: ret <2 x i8> [[SPLAT2]]
+; CHECK-NEXT: ret <2 x i8> <i8 undef, i8 23>
;
%ins2 = insertelement <3 x i8> %x, i8 23, i7 2
%splat2 = shufflevector <3 x i8> %y, <3 x i8> %ins2, <2 x i32> <i32 undef, i32 5>