+; RUN: opt %s -S -simplifycfg | FileCheck %s
+; Check for when one branch implies the value of a successors conditional and
+; it's not simply the same conditional repeated.
+
+define void @test(i32 %length.i, i32 %i) {
+; CHECK-LABEL: @test
+ %iplus1 = add nsw i32 %i, 1
+ %var29 = icmp slt i32 %iplus1, %length.i
+; CHECK: br i1 %var29, label %in_bounds, label %out_of_bounds
+ br i1 %var29, label %next, label %out_of_bounds
+
+next:
+; CHECK-LABEL: in_bounds:
+; CHECK-NEXT: ret void
+ %var30 = icmp slt i32 %i, %length.i
+ br i1 %var30, label %in_bounds, label %out_of_bounds2
+
+in_bounds:
+ ret void
+
+out_of_bounds:
+ call void @foo(i64 0)
+ unreachable
+
+out_of_bounds2:
+ call void @foo(i64 1)
+ unreachable
+}
+
+; If the add is not nsw, it's not safe to use the fact about i+1 to imply the
+; i condition since it could have overflowed.
+define void @test_neg(i32 %length.i, i32 %i) {
+; CHECK-LABEL: @test_neg
+ %iplus1 = add i32 %i, 1
+ %var29 = icmp slt i32 %iplus1, %length.i
+; CHECK: br i1 %var29, label %next, label %out_of_bounds
+ br i1 %var29, label %next, label %out_of_bounds
+
+next:
+ %var30 = icmp slt i32 %i, %length.i
+; CHECK: br i1 %var30, label %in_bounds, label %out_of_bounds2
+ br i1 %var30, label %in_bounds, label %out_of_bounds2
+
+in_bounds:
+ ret void
+
+out_of_bounds:
+ call void @foo(i64 0)
+ unreachable
+
+out_of_bounds2:
+ call void @foo(i64 1)
+ unreachable
+}
+
+
+define void @test2(i32 %length.i, i32 %i) {
+; CHECK-LABEL: @test2
+ %iplus100 = add nsw i32 %i, 100
+ %var29 = icmp slt i32 %iplus100, %length.i
+; CHECK: br i1 %var29, label %in_bounds, label %out_of_bounds
+ br i1 %var29, label %next, label %out_of_bounds
+
+next:
+ %var30 = icmp slt i32 %i, %length.i
+ br i1 %var30, label %in_bounds, label %out_of_bounds2
+
+in_bounds:
+ ret void
+
+out_of_bounds:
+ call void @foo(i64 0)
+ unreachable
+
+out_of_bounds2:
+ call void @foo(i64 1)
+ unreachable
+}
+
+declare void @foo(i64)
+