diff --git a/llvm/test/Transforms/InstCombine/icmp-of-or-x.ll b/llvm/test/Transforms/InstCombine/icmp-of-or-x.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/icmp-of-or-x.ll
@@ -0,0 +1,219 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+
+declare void @llvm.assume(i1)
+declare void @barrier()
+declare void @use.v2i8(<2 x i8>)
+
+define i1 @or_ugt(i8 %x, i8 %y) {
+; CHECK-LABEL: @or_ugt(
+; CHECK-NEXT:    [[XN1:%.*]] = or i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[XN1]], [[X]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %xn1 = or i8 %x, %y
+  %r = icmp ugt i8 %xn1, %x
+  ret i1 %r
+}
+
+define <2 x i1> @or_ule(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @or_ule(
+; CHECK-NEXT:    [[XN1:%.*]] = or <2 x i8> [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp ule <2 x i8> [[XN1]], [[X]]
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %xn1 = or <2 x i8> %x, %y
+  %r = icmp ule <2 x i8> %xn1, %x
+  ret <2 x i1> %r
+}
+
+define <2 x i1> @or_slt_pos(<2 x i8> %xx, <2 x i8> %yy, <2 x i8> %z) {
+; CHECK-LABEL: @or_slt_pos(
+; CHECK-NEXT:    [[X:%.*]] = add <2 x i8> [[XX:%.*]], [[Z:%.*]]
+; CHECK-NEXT:    [[Y:%.*]] = and <2 x i8> [[YY:%.*]], <i8 127, i8 127>
+; CHECK-NEXT:    [[XN1:%.*]] = or <2 x i8> [[X]], [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp slt <2 x i8> [[X]], [[XN1]]
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %x = add <2 x i8> %xx, %z
+  %y = and <2 x i8> %yy, <i8 127, i8 127>
+  %xn1 = or <2 x i8> %x, %y
+  %r = icmp slt <2 x i8> %x, %xn1
+  ret <2 x i1> %r
+}
+
+define i1 @or_sle_pos(i8 %x, i8 %y) {
+; CHECK-LABEL: @or_sle_pos(
+; CHECK-NEXT:    [[NS:%.*]] = icmp sgt i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @llvm.assume(i1 [[NS]])
+; CHECK-NEXT:    [[XN1:%.*]] = or i8 [[X:%.*]], [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp sle i8 [[XN1]], [[X]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ns = icmp sge i8 %y, 0
+  call void @llvm.assume(i1 %ns)
+  %xn1 = or i8 %x, %y
+  %r = icmp sle i8 %xn1, %x
+  ret i1 %r
+}
+
+define i1 @or_sle_fail_maybe_neg(i8 %x, i8 %y) {
+; CHECK-LABEL: @or_sle_fail_maybe_neg(
+; CHECK-NEXT:    [[XN1:%.*]] = or i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp sle i8 [[XN1]], [[X]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %xn1 = or i8 %x, %y
+  %r = icmp sle i8 %xn1, %x
+  ret i1 %r
+}
+
+define i1 @or_eq_noundef(i8 %x, i8 noundef %y) {
+; CHECK-LABEL: @or_eq_noundef(
+; CHECK-NEXT:    [[XN1:%.*]] = or i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[XN1]], [[X]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %xn1 = or i8 %x, %y
+  %r = icmp eq i8 %xn1, %x
+  ret i1 %r
+}
+
+define i1 @or_eq_fail_maybe_undef(i8 %x, i8 %y) {
+; CHECK-LABEL: @or_eq_fail_maybe_undef(
+; CHECK-NEXT:    [[XN1:%.*]] = or i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[XN1]], [[X]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %xn1 = or i8 %x, %y
+  %r = icmp eq i8 %xn1, %x
+  ret i1 %r
+}
+
+define <2 x i1> @or_ne_noundef(<2 x i8> %x, <2 x i8> noundef %y) {
+; CHECK-LABEL: @or_ne_noundef(
+; CHECK-NEXT:    [[XN1:%.*]] = or <2 x i8> [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp ne <2 x i8> [[XN1]], [[X]]
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %xn1 = or <2 x i8> %x, %y
+  %r = icmp ne <2 x i8> %xn1, %x
+  ret <2 x i1> %r
+}
+
+define <2 x i1> @or_ne_noundef_fail_reuse(<2 x i8> %x, <2 x i8> noundef %y) {
+; CHECK-LABEL: @or_ne_noundef_fail_reuse(
+; CHECK-NEXT:    [[XN1:%.*]] = or <2 x i8> [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp ne <2 x i8> [[XN1]], [[X]]
+; CHECK-NEXT:    call void @use.v2i8(<2 x i8> [[XN1]])
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %xn1 = or <2 x i8> %x, %y
+  %r = icmp ne <2 x i8> %xn1, %x
+  call void @use.v2i8(<2 x i8> %xn1)
+  ret <2 x i1> %r
+}
+
+define i1 @or_slt_intmin(i8 %x) {
+; CHECK-LABEL: @or_slt_intmin(
+; CHECK-NEXT:    [[XN1:%.*]] = or i8 [[X:%.*]], -128
+; CHECK-NEXT:    [[R:%.*]] = icmp slt i8 [[XN1]], [[X]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %xn1 = or i8 %x, 128
+  %r = icmp slt i8 %xn1, %x
+  ret i1 %r
+}
+
+define <2 x i1> @or_slt_intmin_2(<2 x i8> %xx, <2 x i8> %z) {
+; CHECK-LABEL: @or_slt_intmin_2(
+; CHECK-NEXT:    [[X:%.*]] = add <2 x i8> [[XX:%.*]], [[Z:%.*]]
+; CHECK-NEXT:    [[XN1:%.*]] = or <2 x i8> [[X]], <i8 -128, i8 -128>
+; CHECK-NEXT:    [[R:%.*]] = icmp slt <2 x i8> [[X]], [[XN1]]
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %x = add <2 x i8> %xx, %z
+  %xn1 = or <2 x i8> %x, <i8 128, i8 128>
+  %r = icmp slt <2 x i8> %x, %xn1
+  ret <2 x i1> %r
+}
+
+define i1 @or_sle_intmin_indirect_2(i8 %xx, i8 %C, i8 %z) {
+; CHECK-LABEL: @or_sle_intmin_indirect_2(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[C:%.*]], -128
+; CHECK-NEXT:    br i1 [[CMP]], label [[NEG:%.*]], label [[POS:%.*]]
+; CHECK:       neg:
+; CHECK-NEXT:    [[NC:%.*]] = sub i8 0, [[C]]
+; CHECK-NEXT:    [[CP2:%.*]] = and i8 [[NC]], [[C]]
+; CHECK-NEXT:    [[X:%.*]] = add i8 [[XX:%.*]], [[Z:%.*]]
+; CHECK-NEXT:    [[XN1:%.*]] = or i8 [[X]], [[CP2]]
+; CHECK-NEXT:    [[R:%.*]] = icmp sle i8 [[X]], [[XN1]]
+; CHECK-NEXT:    ret i1 [[R]]
+; CHECK:       pos:
+; CHECK-NEXT:    call void @barrier()
+; CHECK-NEXT:    ret i1 false
+;
+  %x = add i8 %xx, %z
+  %NC = sub i8 0, %C
+  %CP2 = and i8 %C, %NC
+  %cmp = icmp slt i8 %CP2, 0
+  br i1 %cmp, label %neg, label %pos
+neg:
+  %xn1 = or i8 %x, %CP2
+  %r = icmp sle i8 %x, %xn1
+  ret i1 %r
+pos:
+  call void @barrier()
+  ret i1 0
+}
+
+define i1 @or_sge_intmin(i8 %x) {
+; CHECK-LABEL: @or_sge_intmin(
+; CHECK-NEXT:    [[XN1:%.*]] = or i8 [[X:%.*]], -128
+; CHECK-NEXT:    [[R:%.*]] = icmp sge i8 [[XN1]], [[X]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %xn1 = or i8 %x, 128
+  %r = icmp sge i8 %xn1, %x
+  ret i1 %r
+}
+
+define i1 @or_sgt_intmin_indirect(i8 %x, i8 %C) {
+; CHECK-LABEL: @or_sgt_intmin_indirect(
+; CHECK-NEXT:    [[C_NOT:%.*]] = icmp eq i8 [[C:%.*]], -128
+; CHECK-NEXT:    br i1 [[C_NOT]], label [[NEG:%.*]], label [[POS:%.*]]
+; CHECK:       neg:
+; CHECK-NEXT:    [[NC:%.*]] = sub i8 0, [[C]]
+; CHECK-NEXT:    [[CP2:%.*]] = and i8 [[NC]], [[C]]
+; CHECK-NEXT:    [[XN1:%.*]] = or i8 [[CP2]], [[X:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp sgt i8 [[XN1]], [[X]]
+; CHECK-NEXT:    ret i1 [[R]]
+; CHECK:       pos:
+; CHECK-NEXT:    call void @barrier()
+; CHECK-NEXT:    ret i1 false
+;
+  %NC = sub i8 0, %C
+  %CP2 = and i8 %C, %NC
+  %c = icmp sge i8 %CP2, 0
+  br i1 %c, label %pos, label %neg
+neg:
+  %xn1 = or i8 %x, %CP2
+  %r = icmp sgt i8 %xn1, %x
+  ret i1 %r
+pos:
+  call void @barrier()
+  ret i1 0
+}
+
+define <2 x i1> @or_sgt_intmin_2(<2 x i8> %xx, <2 x i8> %z) {
+; CHECK-LABEL: @or_sgt_intmin_2(
+; CHECK-NEXT:    [[X:%.*]] = add <2 x i8> [[XX:%.*]], [[Z:%.*]]
+; CHECK-NEXT:    [[XN1:%.*]] = or <2 x i8> [[X]], <i8 -128, i8 -128>
+; CHECK-NEXT:    [[R:%.*]] = icmp sgt <2 x i8> [[X]], [[XN1]]
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %x = add <2 x i8> %xx, %z
+  %xn1 = or <2 x i8> %x, <i8 128, i8 128>
+  %r = icmp sgt <2 x i8> %x, %xn1
+  ret <2 x i1> %r
+}