diff --git a/test/Transforms/InstCombine/vec_shuffle.ll b/test/Transforms/InstCombine/vec_shuffle.ll
index 55c0702f710..3ba0d41ba71 100644
--- a/test/Transforms/InstCombine/vec_shuffle.ll
+++ b/test/Transforms/InstCombine/vec_shuffle.ll
@@ -1468,9 +1468,52 @@ define <4 x i32> @splat_assoc_add(<4 x i32> %x, <4 x i32> %y) {
   ret <4 x i32> %r
 }
 
+; Undefs in splat mask are replaced with defined splat index
+
+define <4 x i32> @splat_assoc_add_undef_mask_elts(<4 x i32> %x, <4 x i32> %y) {
+; CHECK-LABEL: @splat_assoc_add_undef_mask_elts(
+; CHECK-NEXT:    [[TMP1:%.*]] = add <4 x i32> [[X:%.*]], <i32 42, i32 undef, i32 undef, i32 undef>
+; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = add <4 x i32> [[TMP2]], [[Y:%.*]]
+; CHECK-NEXT:    ret <4 x i32> [[R]]
+;
+  %splatx = shufflevector <4 x i32> %x, <4 x i32> undef, <4 x i32> <i32 0, i32 0, i32 undef, i32 undef>
+  %a = add <4 x i32> %y, <i32 42, i32 42, i32 42, i32 42>
+  %r = add <4 x i32> %splatx, %a
+  ret <4 x i32> %r
+}
+
+; Undefs in splat mask are replaced with defined splat index
+
+define <4 x i32> @splat_assoc_add_undef_mask_elt_at_splat_index(<4 x i32> %x, <4 x i32> %y) {
+; CHECK-LABEL: @splat_assoc_add_undef_mask_elt_at_splat_index(
+; CHECK-NEXT:    [[TMP1:%.*]] = add <4 x i32> [[X:%.*]], <i32 42, i32 undef, i32 undef, i32 undef>
+; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <4 x i32> [[TMP1]], <4 x i32> undef, <4 x i32> zeroinitializer
+; CHECK-NEXT:    [[R:%.*]] = add <4 x i32> [[TMP2]], [[Y:%.*]]
+; CHECK-NEXT:    ret <4 x i32> [[R]]
+;
+  %splatx = shufflevector <4 x i32> %x, <4 x i32> undef, <4 x i32> <i32 undef, i32 0, i32 0, i32 0>
+  %a = add <4 x i32> %y, <i32 42, i32 42, i32 42, i32 42>
+  %r = add <4 x i32> %splatx, %a
+  ret <4 x i32> %r
+}
+
 define <4 x i32> @splat_assoc_add_undef_constant_elts(<4 x i32> %x, <4 x i32> %y) {
 ; CHECK-LABEL: @splat_assoc_add_undef_constant_elts(
 ; CHECK-NEXT:    [[SPLATX:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> undef, <4 x i32> zeroinitializer
+; CHECK-NEXT:    [[A:%.*]] = add <4 x i32> [[Y:%.*]], <i32 42, i32 undef, i32 undef, i32 42>
+; CHECK-NEXT:    [[R:%.*]] = add <4 x i32> [[SPLATX]], [[A]]
+; CHECK-NEXT:    ret <4 x i32> [[R]]
+;
+  %splatx = shufflevector <4 x i32> %x, <4 x i32> undef, <4 x i32> zeroinitializer
+  %a = add <4 x i32> %y, <i32 42, i32 undef, i32 undef, i32 42>
+  %r = add <4 x i32> %splatx, %a
+  ret <4 x i32> %r
+}
+
+define <4 x i32> @splat_assoc_add_undef_constant_elt_at_splat_index(<4 x i32> %x, <4 x i32> %y) {
+; CHECK-LABEL: @splat_assoc_add_undef_constant_elt_at_splat_index(
+; CHECK-NEXT:    [[SPLATX:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> undef, <4 x i32> zeroinitializer
 ; CHECK-NEXT:    [[A:%.*]] = add <4 x i32> [[Y:%.*]], <i32 undef, i32 42, i32 undef, i32 42>
 ; CHECK-NEXT:    [[R:%.*]] = add <4 x i32> [[SPLATX]], [[A]]
 ; CHECK-NEXT:    ret <4 x i32> [[R]]
@@ -1481,6 +1524,45 @@ define <4 x i32> @splat_assoc_add_undef_constant_elts(<4 x i32> %x, <4 x i32> %y
   ret <4 x i32> %r
 }
 
+define <4 x i32> @splat_assoc_add_undef_mask_elts_undef_constant_elts(<4 x i32> %x, <4 x i32> %y) {
+; CHECK-LABEL: @splat_assoc_add_undef_mask_elts_undef_constant_elts(
+; CHECK-NEXT:    [[SPLATX:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> undef, <4 x i32> <i32 0, i32 undef, i32 0, i32 undef>
+; CHECK-NEXT:    [[A:%.*]] = add <4 x i32> [[Y:%.*]], <i32 42, i32 undef, i32 undef, i32 42>
+; CHECK-NEXT:    [[R:%.*]] = add <4 x i32> [[SPLATX]], [[A]]
+; CHECK-NEXT:    ret <4 x i32> [[R]]
+;
+  %splatx = shufflevector <4 x i32> %x, <4 x i32> undef, <4 x i32> <i32 0, i32 undef, i32 0, i32 undef>
+  %a = add <4 x i32> %y, <i32 42, i32 undef, i32 undef, i32 42>
+  %r = add <4 x i32> %splatx, %a
+  ret <4 x i32> %r
+}
+
+define <4 x i32> @splat_assoc_add_undef_mask_elt_at_splat_index_undef_constant_elts(<4 x i32> %x, <4 x i32> %y) {
+; CHECK-LABEL: @splat_assoc_add_undef_mask_elt_at_splat_index_undef_constant_elts(
+; CHECK-NEXT:    [[SPLATX:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> undef, <4 x i32> <i32 undef, i32 0, i32 0, i32 0>
+; CHECK-NEXT:    [[A:%.*]] = add <4 x i32> [[Y:%.*]], <i32 42, i32 undef, i32 undef, i32 42>
+; CHECK-NEXT:    [[R:%.*]] = add <4 x i32> [[SPLATX]], [[A]]
+; CHECK-NEXT:    ret <4 x i32> [[R]]
+;
+  %splatx = shufflevector <4 x i32> %x, <4 x i32> undef, <4 x i32> <i32 undef, i32 0, i32 0, i32 0>
+  %a = add <4 x i32> %y, <i32 42, i32 undef, i32 undef, i32 42>
+  %r = add <4 x i32> %splatx, %a
+  ret <4 x i32> %r
+}
+
+define <4 x i32> @splat_assoc_add_undef_mask_elt_at_splat_index_undef_constant_elt_at_splat_index(<4 x i32> %x, <4 x i32> %y) {
+; CHECK-LABEL: @splat_assoc_add_undef_mask_elt_at_splat_index_undef_constant_elt_at_splat_index(
+; CHECK-NEXT:    [[SPLATX:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> undef, <4 x i32> <i32 undef, i32 0, i32 0, i32 0>
+; CHECK-NEXT:    [[A:%.*]] = add <4 x i32> [[Y:%.*]], <i32 undef, i32 42, i32 undef, i32 42>
+; CHECK-NEXT:    [[R:%.*]] = add <4 x i32> [[SPLATX]], [[A]]
+; CHECK-NEXT:    ret <4 x i32> [[R]]
+;
+  %splatx = shufflevector <4 x i32> %x, <4 x i32> undef, <4 x i32> <i32 undef, i32 0, i32 0, i32 0>
+  %a = add <4 x i32> %y, <i32 undef, i32 42, i32 undef, i32 42>
+  %r = add <4 x i32> %splatx, %a
+  ret <4 x i32> %r
+}
+
 ; Non-zero splat index; commute operands; FMF intersect
 
 define <2 x float> @splat_assoc_fmul(<2 x float> %x, <2 x float> %y) {
@@ -1500,7 +1582,7 @@ define <2 x float> @splat_assoc_fmul(<2 x float> %x, <2 x float> %y) {
 
 define <3 x i8> @splat_assoc_mul(<3 x i8> %x, <3 x i8> %y, <3 x i8> %z) {
 ; CHECK-LABEL: @splat_assoc_mul(
-; CHECK-NEXT:    [[TMP1:%.*]] = mul <3 x i8> [[X:%.*]], [[Z:%.*]]
+; CHECK-NEXT:    [[TMP1:%.*]] = mul <3 x i8> [[Z:%.*]], [[X:%.*]]
 ; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <3 x i8> [[TMP1]], <3 x i8> undef, <3 x i32> <i32 2, i32 2, i32 2>
 ; CHECK-NEXT:    [[R:%.*]] = mul <3 x i8> [[TMP2]], [[Y:%.*]]
 ; CHECK-NEXT:    ret <3 x i8> [[R]]
@@ -1512,15 +1594,58 @@ define <3 x i8> @splat_assoc_mul(<3 x i8> %x, <3 x i8> %y, <3 x i8> %z) {
   ret <3 x i8> %r
 }
 
-define <3 x i8> @splat_assoc_mul_undef_elts(<3 x i8> %x, <3 x i8> %y, <3 x i8> %z) {
-; CHECK-LABEL: @splat_assoc_mul_undef_elts(
-; CHECK-NEXT:    [[SPLATX:%.*]] = shufflevector <3 x i8> [[X:%.*]], <3 x i8> undef, <3 x i32> <i32 2, i32 undef, i32 2>
+define <3 x i8> @splat_assoc_mul_undef_elt1(<3 x i8> %x, <3 x i8> %y, <3 x i8> %z) {
+; CHECK-LABEL: @splat_assoc_mul_undef_elt1(
+; CHECK-NEXT:    [[TMP1:%.*]] = mul <3 x i8> [[Z:%.*]], [[X:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <3 x i8> [[TMP1]], <3 x i8> undef, <3 x i32> <i32 2, i32 2, i32 2>
+; CHECK-NEXT:    [[R:%.*]] = mul <3 x i8> [[TMP2]], [[Y:%.*]]
+; CHECK-NEXT:    ret <3 x i8> [[R]]
+;
+  %splatx = shufflevector <3 x i8> %x, <3 x i8> undef, <3 x i32> <i32 undef, i32 2, i32 2>
+  %splatz = shufflevector <3 x i8> %z, <3 x i8> undef, <3 x i32> <i32 2, i32 2, i32 2>
+  %a = mul nsw <3 x i8> %y, %splatz
+  %r = mul nsw nuw <3 x i8> %a, %splatx
+  ret <3 x i8> %r
+}
+
+define <3 x i8> @splat_assoc_mul_undef_elt2(<3 x i8> %x, <3 x i8> %y, <3 x i8> %z) {
+; CHECK-LABEL: @splat_assoc_mul_undef_elt2(
+; CHECK-NEXT:    [[SPLATX:%.*]] = shufflevector <3 x i8> [[X:%.*]], <3 x i8> undef, <3 x i32> <i32 2, i32 2, i32 2>
+; CHECK-NEXT:    [[SPLATZ:%.*]] = shufflevector <3 x i8> [[Z:%.*]], <3 x i8> undef, <3 x i32> <i32 undef, i32 2, i32 2>
+; CHECK-NEXT:    [[A:%.*]] = mul nsw <3 x i8> [[SPLATZ]], [[Y:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = mul nuw nsw <3 x i8> [[A]], [[SPLATX]]
+; CHECK-NEXT:    ret <3 x i8> [[R]]
+;
+  %splatx = shufflevector <3 x i8> %x, <3 x i8> undef, <3 x i32> <i32 2, i32 2, i32 2>
+  %splatz = shufflevector <3 x i8> %z, <3 x i8> undef, <3 x i32> <i32 undef, i32 2, i32 2>
+  %a = mul nsw <3 x i8> %y, %splatz
+  %r = mul nsw nuw <3 x i8> %a, %splatx
+  ret <3 x i8> %r
+}
+
+define <3 x i8> @splat_assoc_mul_undef_elt_at_splat_index1(<3 x i8> %x, <3 x i8> %y, <3 x i8> %z) {
+; CHECK-LABEL: @splat_assoc_mul_undef_elt_at_splat_index1(
+; CHECK-NEXT:    [[TMP1:%.*]] = mul <3 x i8> [[Z:%.*]], [[X:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <3 x i8> [[TMP1]], <3 x i8> undef, <3 x i32> <i32 2, i32 2, i32 2>
+; CHECK-NEXT:    [[R:%.*]] = mul <3 x i8> [[TMP2]], [[Y:%.*]]
+; CHECK-NEXT:    ret <3 x i8> [[R]]
+;
+  %splatx = shufflevector <3 x i8> %x, <3 x i8> undef, <3 x i32> <i32 2, i32 2, i32 undef>
+  %splatz = shufflevector <3 x i8> %z, <3 x i8> undef, <3 x i32> <i32 2, i32 2, i32 2>
+  %a = mul nsw <3 x i8> %y, %splatz
+  %r = mul nsw nuw <3 x i8> %a, %splatx
+  ret <3 x i8> %r
+}
+
+define <3 x i8> @splat_assoc_mul_undef_elt_at_splat_index2(<3 x i8> %x, <3 x i8> %y, <3 x i8> %z) {
+; CHECK-LABEL: @splat_assoc_mul_undef_elt_at_splat_index2(
+; CHECK-NEXT:    [[SPLATX:%.*]] = shufflevector <3 x i8> [[X:%.*]], <3 x i8> undef, <3 x i32> <i32 2, i32 2, i32 2>
 ; CHECK-NEXT:    [[SPLATZ:%.*]] = shufflevector <3 x i8> [[Z:%.*]], <3 x i8> undef, <3 x i32> <i32 2, i32 2, i32 undef>
 ; CHECK-NEXT:    [[A:%.*]] = mul nsw <3 x i8> [[SPLATZ]], [[Y:%.*]]
 ; CHECK-NEXT:    [[R:%.*]] = mul nuw nsw <3 x i8> [[A]], [[SPLATX]]
 ; CHECK-NEXT:    ret <3 x i8> [[R]]
 ;
-  %splatx = shufflevector <3 x i8> %x, <3 x i8> undef, <3 x i32> <i32 2, i32 undef, i32 2>
+  %splatx = shufflevector <3 x i8> %x, <3 x i8> undef, <3 x i32> <i32 2, i32 2, i32 2>
   %splatz = shufflevector <3 x i8> %z, <3 x i8> undef, <3 x i32> <i32 2, i32 2, i32 undef>
   %a = mul nsw <3 x i8> %y, %splatz
   %r = mul nsw nuw <3 x i8> %a, %splatx