--- /dev/null
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -instcombine -S < %s | FileCheck %s
+
+define zeroext i1 @switch_ob_one_two_cases(i32 %arg) {
+; CHECK-LABEL: @switch_ob_one_two_cases(
+; CHECK-NEXT: bb:
+; CHECK-NEXT: [[TMP0:%.*]] = and i32 [[ARG:%.*]], -3
+; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i32 [[TMP0]], 0
+; CHECK-NEXT: ret i1 [[TMP1]]
+;
+bb:
+ switch i32 %arg, label %bb1 [
+ i32 0, label %bb2
+ i32 2, label %bb2
+ ]
+
+bb1:
+ br label %bb2
+
+bb2:
+ %i = phi i1 [ false, %bb1 ], [ true, %bb ], [ true, %bb ]
+ ret i1 %i
+}
+
+define zeroext i1 @switch_ob_one_two_cases2(i32 %arg) {
+; CHECK-LABEL: @switch_ob_one_two_cases2(
+; CHECK-NEXT: [[I:%.*]] = icmp eq i32 [[ARG:%.*]], 7
+; CHECK-NEXT: [[I1:%.*]] = icmp eq i32 [[ARG]], 11
+; CHECK-NEXT: [[I2:%.*]] = or i1 [[I]], [[I1]]
+; CHECK-NEXT: ret i1 [[I2]]
+;
+ %i = icmp eq i32 %arg, 7
+ %i1 = icmp eq i32 %arg, 11
+ %i2 = or i1 %i, %i1
+ ret i1 %i2
+}