1; RUN: opt < %s -S -ipsccp | FileCheck %s
2; PR5596
3
4; IPSCCP should propagate the 0 argument, eliminate the switch, and propagate
5; the result.
6
7; CHECK: define i32 @main() #0 {
8; CHECK-NEXT: entry:
9; CHECK-NEXT: %call2 = tail call i32 @wwrite(i64 0) [[NUW:#[0-9]+]]
10; CHECK-NEXT: ret i32 123
11
12define i32 @main() noreturn nounwind {
13entry:
14  %call2 = tail call i32 @wwrite(i64 0) nounwind
15  ret i32 %call2
16}
17
18define internal i32 @wwrite(i64 %i) nounwind readnone {
19entry:
20  switch i64 %i, label %sw.default [
21    i64 3, label %return
22    i64 10, label %return
23  ]
24
25sw.default:
26  ret i32 123
27
28return:
29  ret i32 0
30}
31
32; CHECK: attributes #0 = { noreturn nounwind }
33; CHECK: attributes #1 = { nounwind readnone }
34; CHECK: attributes [[NUW]] = { nounwind }
35