1 files changed, 55 insertions, 1 deletions
diff --git a/test/Transforms/InstSimplify/div.ll b/test/Transforms/InstSimplify/div.ll
index b8ce34aaa37e6..f096719359dcd 100644
--- a/test/Transforms/InstSimplify/div.ll
+++ b/test/Transforms/InstSimplify/div.ll
@@ -1,10 +1,64 @@
 ; RUN: opt < %s -instsimplify -S | FileCheck %s
 
+; Division-by-zero is undef. UB in any vector lane means the whole op is undef.
+
+define <2 x i8> @sdiv_zero_elt_vec_constfold(<2 x i8> %x) {
+; CHECK-LABEL: @sdiv_zero_elt_vec_constfold(
+; CHECK-NEXT:    ret <2 x i8> undef
+;
+  %div = sdiv <2 x i8> <i8 1, i8 2>, <i8 0, i8 -42>
+  ret <2 x i8> %div
+}
+
+define <2 x i8> @udiv_zero_elt_vec_constfold(<2 x i8> %x) {
+; CHECK-LABEL: @udiv_zero_elt_vec_constfold(
+; CHECK-NEXT:    ret <2 x i8> undef
+;
+  %div = udiv <2 x i8> <i8 1, i8 2>, <i8 42, i8 0>
+  ret <2 x i8> %div
+}
+
+define <2 x i8> @sdiv_zero_elt_vec(<2 x i8> %x) {
+; CHECK-LABEL: @sdiv_zero_elt_vec(
+; CHECK-NEXT:    ret <2 x i8> undef
+;
+  %div = sdiv <2 x i8> %x, <i8 -42, i8 0>
+  ret <2 x i8> %div
+}
+
+define <2 x i8> @udiv_zero_elt_vec(<2 x i8> %x) {
+; CHECK-LABEL: @udiv_zero_elt_vec(
+; CHECK-NEXT:    ret <2 x i8> undef
+;
+  %div = udiv <2 x i8> %x, <i8 0, i8 42>
+  ret <2 x i8> %div
+}
+
+; Division-by-zero is undef. UB in any vector lane means the whole op is undef.
+; Thus, we can simplify this: if any element of 'y' is 0, we can do anything.
+; Therefore, assume that all elements of 'y' must be 1.
+
+define <2 x i1> @sdiv_bool_vec(<2 x i1> %x, <2 x i1> %y) {
+; CHECK-LABEL: @sdiv_bool_vec(
+; CHECK-NEXT:    ret <2 x i1> %x
+;
+  %div = sdiv <2 x i1> %x, %y
+  ret <2 x i1> %div
+}
+
+define <2 x i1> @udiv_bool_vec(<2 x i1> %x, <2 x i1> %y) {
+; CHECK-LABEL: @udiv_bool_vec(
+; CHECK-NEXT:    ret <2 x i1> %x
+;
+  %div = udiv <2 x i1> %x, %y
+  ret <2 x i1> %div
+}
+
 declare i32 @external()
 
 define i32 @div1() {
 ; CHECK-LABEL: @div1(
-; CHECK:         [[CALL:%.*]] = call i32 @external(), !range !0
+; CHECK-NEXT:    [[CALL:%.*]] = call i32 @external(), !range !0
 ; CHECK-NEXT:    ret i32 0
 ;
   %call = call i32 @external(), !range !0