1; RUN: opt < %s -loop-unswitch -enable-new-pm=0 -verify-loop-info -S < %s 2>&1 | FileCheck %s
2; RUN: opt < %s -loop-unswitch -enable-new-pm=0 -verify-loop-info -enable-mssa-loop-dependency=true -verify-memoryssa -S < %s 2>&1 | FileCheck %s
3
4; There are 1 case and 1 default case in the switch. after we unswitch, we know the
5; %a is definitely not 0 in one of the unswitched loop, make sure we take advantage
6; of that and simplify the branches in the loop.
7;
8; CHECK: define void @simplify_with_nonvalness(
9
10; This is the loop in which we know %a is definitely 0.
11; CHECK: sw.bb.us:
12; CHECK: br i1 true, label %if.then.us, label %if.end.us
13
14; This is the loop in which we do not know what %a is but we know %a is definitely NOT 0.
15; Make sure we use that information to simplify.
16; The icmp eq i32 %a, 0 in one of the unswitched loop is simplified to false.
17; CHECK: sw.bb.split:
18; CHECK: br i1 false, label %if.then, label %if.end
19
20define void @simplify_with_nonvalness(i32 %a) #0 {
21entry:
22  br label %for.cond
23
24for.cond:
25  %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]
26  %cmp = icmp slt i32 %i.0, 1024
27  br i1 %cmp, label %for.body, label %for.end
28
29for.body:
30  switch i32 %a, label %sw.default [
31    i32 0, label %sw.bb
32  ]
33
34sw.bb:
35  %cmp1 = icmp eq i32 %a, 0
36  br i1 %cmp1, label %if.then, label %if.end
37
38if.then:
39  call void (...) @bar()
40  br label %if.end
41
42if.end:
43  br label %sw.epilog
44
45sw.default:
46  br label %sw.epilog
47
48sw.epilog:
49  br label %for.inc
50
51for.inc:
52  %inc = add nsw i32 %i.0, 1
53  br label %for.cond
54
55for.end:
56  ret void
57}
58
59declare void @bar(...)
60