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 +1,385 @@
+; 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>)
+declare void @use.i8(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_notY_eq_0(i8 %x, i8 %y) {
+; CHECK-LABEL: @or_eq_notY_eq_0(
+; CHECK-NEXT:    [[NY:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[OR:%.*]] = or i8 [[NY]], [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[OR]], [[NY]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %ny = xor i8 %y, -1
+  %or = or i8 %x, %ny
+  %cmp = icmp eq i8 %or, %ny
+  ret i1 %cmp
+}
+
+define i1 @or_eq_notY_eq_0_fail_multiuse(i8 %x, i8 %y) {
+; CHECK-LABEL: @or_eq_notY_eq_0_fail_multiuse(
+; CHECK-NEXT:    [[NY:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[OR:%.*]] = or i8 [[NY]], [[X:%.*]]
+; CHECK-NEXT:    call void @use.i8(i8 [[OR]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[OR]], [[NY]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %ny = xor i8 %y, -1
+  %or = or i8 %x, %ny
+  call void @use.i8(i8 %or)
+  %cmp = icmp eq i8 %or, %ny
+  ret i1 %cmp
+}
+
+define i1 @or_ne_notY_eq_1s(i8 %x, i8 %y) {
+; CHECK-LABEL: @or_ne_notY_eq_1s(
+; CHECK-NEXT:    [[NY:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[OR:%.*]] = or i8 [[NY]], [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i8 [[OR]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %ny = xor i8 %y, -1
+  %or = or i8 %x, %ny
+  %cmp = icmp ne i8 %or, %x
+  ret i1 %cmp
+}
+
+define i1 @or_ne_notY_eq_1s_fail_bad_not(i8 %x, i8 %y) {
+; CHECK-LABEL: @or_ne_notY_eq_1s_fail_bad_not(
+; CHECK-NEXT:    [[NY:%.*]] = xor i8 [[Y:%.*]], -2
+; CHECK-NEXT:    [[OR:%.*]] = or i8 [[NY]], [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i8 [[OR]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %ny = xor i8 %y, -2
+  %or = or i8 %x, %ny
+  %cmp = icmp ne i8 %or, %x
+  ret i1 %cmp
+}
+
+define <2 x i1> @or_ne_vecC(<2 x i8> %x) {
+; CHECK-LABEL: @or_ne_vecC(
+; CHECK-NEXT:    [[OR:%.*]] = or <2 x i8> [[X:%.*]], <i8 9, i8 42>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne <2 x i8> [[OR]], <i8 9, i8 42>
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %or = or <2 x i8> %x, <i8 9, i8 42>
+  %cmp = icmp ne <2 x i8> %or, <i8 9, i8 42>
+  ret <2 x i1> %cmp
+}
+
+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
+}
+
+define i1 @or_simplify_ule(i8 %y_in, i8 %rhs_in, i1 %c) {
+; CHECK-LABEL: @or_simplify_ule(
+; CHECK-NEXT:    [[RHS:%.*]] = and i8 [[RHS_IN:%.*]], -2
+; CHECK-NEXT:    [[Y:%.*]] = or i8 [[Y_IN:%.*]], [[RHS_IN]]
+; CHECK-NEXT:    [[LBO:%.*]] = or i8 [[Y]], 1
+; CHECK-NEXT:    [[R:%.*]] = icmp ule i8 [[LBO]], [[RHS]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %y = or i8 %y_in, 1
+  %rhs = and i8 %rhs_in, -2
+  %lbo = or i8 %y, %rhs
+  %r = icmp ule i8 %lbo, %rhs
+  ret i1 %r
+}
+
+define i1 @or_simplify_uge(i8 %y_in, i8 %rhs_in, i1 %c) {
+; CHECK-LABEL: @or_simplify_uge(
+; CHECK-NEXT:    ret i1 false
+;
+  %y = or i8 %y_in, 129
+  %rhs = and i8 %rhs_in, 127
+  %lbo = or i8 %y, %rhs
+  %r = icmp uge i8 %rhs, %lbo
+  ret i1 %r
+}
+
+define i1 @or_simplify_ule_fail(i8 %y_in, i8 %rhs_in) {
+; CHECK-LABEL: @or_simplify_ule_fail(
+; CHECK-NEXT:    [[RHS:%.*]] = and i8 [[RHS_IN:%.*]], 127
+; CHECK-NEXT:    [[Y:%.*]] = or i8 [[RHS]], [[Y_IN:%.*]]
+; CHECK-NEXT:    [[LBO:%.*]] = or i8 [[Y]], 64
+; CHECK-NEXT:    [[R:%.*]] = icmp ule i8 [[LBO]], [[RHS]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %y = or i8 %y_in, 64
+  %rhs = and i8 %rhs_in, 127
+  %lbo = or i8 %y, %rhs
+  %r = icmp ule i8 %lbo, %rhs
+  ret i1 %r
+}
+
+define i1 @or_simplify_ugt(i8 %y_in, i8 %rhs_in) {
+; CHECK-LABEL: @or_simplify_ugt(
+; CHECK-NEXT:    [[RHS:%.*]] = and i8 [[RHS_IN:%.*]], -2
+; CHECK-NEXT:    [[Y:%.*]] = or i8 [[Y_IN:%.*]], [[RHS_IN]]
+; CHECK-NEXT:    [[LBO:%.*]] = or i8 [[Y]], 1
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[LBO]], [[RHS]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %y = or i8 %y_in, 1
+  %rhs = and i8 %rhs_in, -2
+  %lbo = or i8 %y, %rhs
+  %r = icmp ugt i8 %lbo, %rhs
+  ret i1 %r
+}
+
+define i1 @or_simplify_ult(i8 %y_in, i8 %rhs_in) {
+; CHECK-LABEL: @or_simplify_ult(
+; CHECK-NEXT:    [[RHS:%.*]] = and i8 [[RHS_IN:%.*]], -5
+; CHECK-NEXT:    [[Y:%.*]] = or i8 [[Y_IN:%.*]], [[RHS_IN]]
+; CHECK-NEXT:    [[LBO:%.*]] = or i8 [[Y]], 36
+; CHECK-NEXT:    [[R:%.*]] = icmp ult i8 [[RHS]], [[LBO]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %y = or i8 %y_in, 36
+  %rhs = and i8 %rhs_in, -5
+  %lbo = or i8 %y, %rhs
+  %r = icmp ult i8 %rhs, %lbo
+  ret i1 %r
+}
+
+define i1 @or_simplify_ugt_fail(i8 %y_in, i8 %rhs_in) {
+; CHECK-LABEL: @or_simplify_ugt_fail(
+; CHECK-NEXT:    [[RHS:%.*]] = or i8 [[RHS_IN:%.*]], 1
+; CHECK-NEXT:    [[LBO:%.*]] = or i8 [[RHS]], [[Y_IN:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[LBO]], [[RHS]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %y = and i8 %y_in, -2
+  %rhs = or i8 %rhs_in, 1
+  %lbo = or i8 %y, %rhs
+  %r = icmp ugt i8 %lbo, %rhs
+  ret i1 %r
+}
+
+define i1 @pr64610(ptr %b) {
+; CHECK-LABEL: @pr64610(
+; CHECK-NEXT:    [[V:%.*]] = load i1, ptr [[B:%.*]], align 2
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[V]], i32 74, i32 0
+; CHECK-NEXT:    [[OR:%.*]] = or i32 [[S]], 1
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i32 [[OR]], [[S]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %v = load i1, ptr %b, align 2
+  %s = select i1 %v, i32 74, i32 0
+  %or = or i32 %s, 1
+  %r = icmp ugt i32 %or, %s
+  ret i1 %r
+}