diff --git a/llvm/test/Transforms/InstSimplify/vec-icmp-of-cast.ll b/llvm/test/Transforms/InstSimplify/vec-icmp-of-cast.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/InstSimplify/vec-icmp-of-cast.ll
@@ -0,0 +1,200 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=instsimplify -S | FileCheck %s
+
+define <2 x i1> @icmp_eq_zext_is_false(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_eq_zext_is_false(
+; CHECK-NEXT:    [[XEXT:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <2 x i32> [[XEXT]], <i32 511, i32 1234>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = zext <2 x i8> %x to <2 x i32>
+  %cmp = icmp eq <2 x i32> %xext, <i32 511, i32 1234>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_ugt_zext_is_false(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_ugt_zext_is_false(
+; CHECK-NEXT:    [[XEXT:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt <2 x i32> [[XEXT]], <i32 256, i32 1234>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = zext <2 x i8> %x to <2 x i32>
+  %cmp = icmp ugt <2 x i32> %xext, <i32 256, i32 1234>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_ugt_zext_todo_off_by1(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_ugt_zext_todo_off_by1(
+; CHECK-NEXT:    [[XEXT:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt <2 x i32> [[XEXT]], <i32 1234, i32 255>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = zext <2 x i8> %x to <2 x i32>
+  %cmp = icmp ugt <2 x i32> %xext, <i32 1234, i32 255>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_uge_zext_is_false(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_uge_zext_is_false(
+; CHECK-NEXT:    [[XEXT:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp uge <2 x i32> [[XEXT]], <i32 256, i32 1234>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = zext <2 x i8> %x to <2 x i32>
+  %cmp = icmp uge <2 x i32> %xext, <i32 256, i32 1234>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_eq_zext_fail(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_eq_zext_fail(
+; CHECK-NEXT:    [[XEXT:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <2 x i32> [[XEXT]], <i32 511, i32 123>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = zext <2 x i8> %x to <2 x i32>
+  %cmp = icmp eq <2 x i32> %xext, <i32 511, i32 123>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_eq_zext_unused(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_eq_zext_unused(
+; CHECK-NEXT:    [[XEXT:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <2 x i32> [[XEXT]], <i32 254, i32 123>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = zext <2 x i8> %x to <2 x i32>
+  %cmp = icmp eq <2 x i32> %xext, <i32 254, i32 123>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_ne_zext_is_true(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_ne_zext_is_true(
+; CHECK-NEXT:    [[XEXT:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne <2 x i32> [[XEXT]], <i32 256, i32 1234>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = zext <2 x i8> %x to <2 x i32>
+  %cmp = icmp ne <2 x i32> %xext, <i32 256, i32 1234>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_ult_zext_is_true(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_ult_zext_is_true(
+; CHECK-NEXT:    [[XEXT:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult <2 x i32> [[XEXT]], <i32 256, i32 1234>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = zext <2 x i8> %x to <2 x i32>
+  %cmp = icmp ult <2 x i32> %xext, <i32 256, i32 1234>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_ule_zext_is_true(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_ule_zext_is_true(
+; CHECK-NEXT:    [[XEXT:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ule <2 x i32> [[XEXT]], <i32 256, i32 -1>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = zext <2 x i8> %x to <2 x i32>
+  %cmp = icmp ule <2 x i32> %xext, <i32 256, i32 -1>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_ne_zext_fail(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_ne_zext_fail(
+; CHECK-NEXT:    [[XEXT:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne <2 x i32> [[XEXT]], <i32 256, i32 123>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = zext <2 x i8> %x to <2 x i32>
+  %cmp = icmp ne <2 x i32> %xext, <i32 256, i32 123>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_ne_zext_unused(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_ne_zext_unused(
+; CHECK-NEXT:    [[XEXT:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne <2 x i32> [[XEXT]], <i32 1, i32 123>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = zext <2 x i8> %x to <2 x i32>
+  %cmp = icmp ne <2 x i32> %xext, <i32 1, i32 123>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_sge_zext_is_false_true(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_sge_zext_is_false_true(
+; CHECK-NEXT:    [[XEXT:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge <2 x i32> [[XEXT]], <i32 257, i32 -450>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = zext <2 x i8> %x to <2 x i32>
+  %cmp = icmp sge <2 x i32> %xext, <i32 257, i32 -450>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_sle_zext_is_false_false(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_sle_zext_is_false_false(
+; CHECK-NEXT:    [[XEXT:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sle <2 x i32> [[XEXT]], <i32 -256, i32 -450>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = zext <2 x i8> %x to <2 x i32>
+  %cmp = icmp sle <2 x i32> %xext, <i32 -256, i32 -450>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_eq_sext_is_false(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_eq_sext_is_false(
+; CHECK-NEXT:    [[XEXT:%.*]] = sext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <2 x i32> [[XEXT]], <i32 255, i32 129>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = sext <2 x i8> %x to <2 x i32>
+  %cmp = icmp eq <2 x i32> %xext, <i32 255, i32 129>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_eq_sext_fail(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_eq_sext_fail(
+; CHECK-NEXT:    [[XEXT:%.*]] = sext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <2 x i32> [[XEXT]], <i32 255, i32 -1>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = sext <2 x i8> %x to <2 x i32>
+  %cmp = icmp eq <2 x i32> %xext, <i32 255, i32 -1>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_ne_sext_is_true(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_ne_sext_is_true(
+; CHECK-NEXT:    [[XEXT:%.*]] = sext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne <2 x i32> [[XEXT]], <i32 199, i32 1234>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = sext <2 x i8> %x to <2 x i32>
+  %cmp = icmp ne <2 x i32> %xext, <i32 199, i32 1234>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_sgt_sext_is_true_false(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_sgt_sext_is_true_false(
+; CHECK-NEXT:    [[XEXT:%.*]] = sext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt <2 x i32> [[XEXT]], <i32 -250, i32 450>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = sext <2 x i8> %x to <2 x i32>
+  %cmp = icmp sgt <2 x i32> %xext, <i32 -250, i32 450>
+  ret <2 x i1> %cmp
+}
+
+define <2 x i1> @icmp_slt_sext_is_true_false(<2 x i8> %x) {
+; CHECK-LABEL: @icmp_slt_sext_is_true_false(
+; CHECK-NEXT:    [[XEXT:%.*]] = sext <2 x i8> [[X:%.*]] to <2 x i32>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt <2 x i32> [[XEXT]], <i32 257, i32 -450>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %xext = sext <2 x i8> %x to <2 x i32>
+  %cmp = icmp slt <2 x i32> %xext, <i32 257, i32 -450>
+  ret <2 x i1> %cmp
+}