ret <2 x float> %r
}
+; TODO: Reduce the width of the binop by moving it ahead of a shuffle.
+
+define <4 x i8> @widening_shuffle_add_1(<2 x i8> %x) {
+; CHECK-LABEL: @widening_shuffle_add_1(
+; CHECK-NEXT: [[WIDEX:%.*]] = shufflevector <2 x i8> [[X:%.*]], <2 x i8> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
+; CHECK-NEXT: [[R:%.*]] = add <4 x i8> [[WIDEX]], <i8 42, i8 43, i8 44, i8 45>
+; CHECK-NEXT: ret <4 x i8> [[R]]
+;
+ %widex = shufflevector <2 x i8> %x, <2 x i8> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
+ %r = add <4 x i8> %widex, <i8 42, i8 43, i8 44, i8 45>
+ ret <4 x i8> %r
+}
+
+; TODO: Reduce the width of the binop by moving it ahead of a shuffle.
+
+define <4 x i8> @widening_shuffle_add_2(<2 x i8> %x) {
+; CHECK-LABEL: @widening_shuffle_add_2(
+; CHECK-NEXT: [[WIDEX:%.*]] = shufflevector <2 x i8> [[X:%.*]], <2 x i8> undef, <4 x i32> <i32 1, i32 0, i32 undef, i32 undef>
+; CHECK-NEXT: [[R:%.*]] = add <4 x i8> [[WIDEX]], <i8 42, i8 43, i8 44, i8 45>
+; CHECK-NEXT: ret <4 x i8> [[R]]
+;
+ %widex = shufflevector <2 x i8> %x, <2 x i8> undef, <4 x i32> <i32 1, i32 0, i32 undef, i32 undef>
+ %r = add <4 x i8> %widex, <i8 42, i8 43, i8 44, i8 45>
+ ret <4 x i8> %r
+}
+
+; Widening shuffles have the same mask/constant constraint as non-size-changing shuffles.
+
+define <4 x i8> @widening_shuffle_add_invalid_constant(<2 x i8> %x) {
+; CHECK-LABEL: @widening_shuffle_add_invalid_constant(
+; CHECK-NEXT: [[WIDEX:%.*]] = shufflevector <2 x i8> [[X:%.*]], <2 x i8> undef, <4 x i32> <i32 1, i32 1, i32 undef, i32 undef>
+; CHECK-NEXT: [[R:%.*]] = add <4 x i8> [[WIDEX]], <i8 42, i8 43, i8 44, i8 45>
+; CHECK-NEXT: ret <4 x i8> [[R]]
+;
+ %widex = shufflevector <2 x i8> %x, <2 x i8> undef, <4 x i32> <i32 1, i32 1, i32 undef, i32 undef>
+ %r = add <4 x i8> %widex, <i8 42, i8 43, i8 44, i8 45>
+ ret <4 x i8> %r
+}
+
+; And widening shuffles have an additional constraint - they must not extend with anything but undefs.
+
+define <4 x i8> @widening_shuffle_add_invalid_mask(<2 x i8> %x) {
+; CHECK-LABEL: @widening_shuffle_add_invalid_mask(
+; CHECK-NEXT: [[WIDEX:%.*]] = shufflevector <2 x i8> [[X:%.*]], <2 x i8> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 0>
+; CHECK-NEXT: [[R:%.*]] = add <4 x i8> [[WIDEX]], <i8 42, i8 43, i8 44, i8 45>
+; CHECK-NEXT: ret <4 x i8> [[R]]
+;
+ %widex = shufflevector <2 x i8> %x, <2 x i8> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 0>
+ %r = add <4 x i8> %widex, <i8 42, i8 43, i8 44, i8 45>
+ ret <4 x i8> %r
+}
+
define <4 x i32> @shuffle_17add2(<4 x i32> %v) {
; CHECK-LABEL: @shuffle_17add2(
; CHECK-NEXT: [[TMP1:%.*]] = shl <4 x i32> [[V:%.*]], <i32 1, i32 1, i32 1, i32 1>