1; RUN: opt -verify-loop-info -irce-print-changed-loops -irce -S
2
3; Make sure that IRCE doesn't apply in case of empty ranges.
4; (i + 30 < 40) if i in [-30, 10).
5; Intersected with iteration space, it is [0, 10).
6; (i - 60 < 40) if i in [60 , 100).
7; The intersection with safe iteration space is the empty range [60, 10).
8; It is better to eliminate one range check than attempt to eliminate both given
9; that we will never go to the main loop in the latter case and basically
10; only duplicate code with no benefits.
11
12define void @test_01(i32* %arr, i32* %a_len_ptr) #0 {
13
14; CHECK-LABEL: test_01(
15; CHECK-NOT:   preloop
16; CHECK:       entry:
17; CHECK-NEXT:    br i1 true, label %loop.preheader, label %main.pseudo.exit
18; CHECK:       in.bounds.1:
19; CHECK-NEXT:    %addr = getelementptr i32, i32* %arr, i32 %idx
20; CHECK-NEXT:    store i32 0, i32* %addr
21; CHECK-NEXT:    %off1 = add i32 %idx, 30
22; CHECK-NEXT:    %c2 = icmp slt i32 %off1, 40
23; CHECK-NEXT:    br i1 true, label %in.bounds.2, label %exit.loopexit2
24; CHECK:       in.bounds.2:
25; CHECK-NEXT:    %off2 = add i32 %idx, -60
26; CHECK-NEXT:    %c3 = icmp slt i32 %off2, 40
27; CHECK-NEXT:    br i1 %c3, label %in.bounds.3, label %exit.loopexit2
28; CHECK:       in.bounds.3:
29; CHECK-NEXT:    %next = icmp ult i32 %idx.next, 100
30; CHECK-NEXT:    [[COND1:%[^ ]+]] = icmp ult i32 %idx.next, 10
31; CHECK-NEXT:    br i1 [[COND1]], label %loop, label %main.exit.selector
32; CHECK:       main.exit.selector:
33; CHECK-NEXT:    %idx.next.lcssa = phi i32 [ %idx.next, %in.bounds.3 ]
34; CHECK-NEXT:    [[COND2:%[^ ]+]] = icmp ult i32 %idx.next.lcssa, 100
35; CHECK-NEXT:    br i1 [[COND2]], label %main.pseudo.exit, label %exit
36; CHECK:       postloop:
37
38entry:
39  br label %loop
40
41loop:
42  %idx = phi i32 [ 0, %entry ], [ %idx.next, %in.bounds.3 ]
43  %idx.next = add nsw nuw i32 %idx, 1
44  %c1 = icmp slt i32 %idx, 20
45  br i1 %c1, label %in.bounds.1, label %out.of.bounds
46
47in.bounds.1:
48  %addr = getelementptr i32, i32* %arr, i32 %idx
49  store i32 0, i32* %addr
50  %off1 = add i32 %idx, 30
51  %c2 = icmp slt i32 %off1, 40
52  br i1 %c2, label %in.bounds.2, label %exit
53
54in.bounds.2:
55  %off2 = add i32 %idx, -60
56  %c3 = icmp slt i32 %off2, 40
57  br i1 %c3, label %in.bounds.3, label %exit
58
59in.bounds.3:
60  %next = icmp ult i32 %idx.next, 100
61  br i1 %next, label %loop, label %exit
62
63out.of.bounds:
64  ret void
65
66exit:
67  ret void
68}
69