xref: /llvm-project/llvm/test/Transforms/LoopUnrollAndJam/multiple_exit_blocks.ll (revision 055fb7795aa219a3d274d280ec9129784f169f56)
1; REQUIRES: asserts
2; RUN: opt -debug-only=loop-unroll-and-jam -passes="loop-unroll-and-jam" -enable-unroll-and-jam -allow-unroll-and-jam -unroll-and-jam-count=8 -disable-output %s 2>&1 | FileCheck %s
3
4; CHECK: Loop Unroll and Jam: F[h] Loop %bb8
5; CHECK: Won't unroll-and-jam; only loops with single exit blocks can be unrolled and jammed
6
7@a = external global i16, align 2
8@e = external global i32, align 4
9@f = external global i16, align 2
10@b = external global i16, align 2
11@c = external global i64, align 8
12
13define void @h() {
14bb:
15  store i32 4, ptr @e, align 4
16  %i15 = load i16, ptr @b, align 2
17  %i17 = icmp slt i16 %i15, 1
18  br label %bb8
19
20bb8:                                              ; preds = %bb, %bb47
21  %storemerge15 = phi i32 [ 4, %bb ], [ %i49, %bb47 ]
22  br label %bb24
23
24bb24:                                             ; preds = %bb43, %bb8
25  %storemerge312 = phi i16 [ 0, %bb8 ], [ %i45, %bb43 ]
26  br i1 %i17, label %bb46.preheader, label %bb43
27
28bb46.preheader:                                   ; preds = %bb24
29  store i16 %storemerge312, ptr @f, align 2
30  br label %bb46
31
32bb43:                                             ; preds = %bb24
33  %i45 = add nuw nsw i16 %storemerge312, 1
34  %i13 = icmp ult i16 %storemerge312, 7
35  br i1 %i13, label %bb24, label %bb47
36
37bb46:                                             ; preds = %bb46.preheader, %bb46
38  br label %bb46
39
40bb47:                                             ; preds = %bb43
41  %i49 = add nsw i32 %storemerge15, -1
42  store i32 %i49, ptr @e, align 4
43  %i7.not = icmp eq i32 %i49, 0
44  br i1 %i7.not, label %bb50, label %bb8
45
46bb50:                                             ; preds = %bb47
47  store i16 %i45, ptr @f, align 2
48  ret void
49}
50