xref: /llvm-project/llvm/test/Transforms/LoopSimplify/update_latch_md.ll (revision 80a89c55c6d958dc100c91d9e87c0f6e9f6794a6)
1; RUN: opt -passes=loop-simplify -S < %s | FileCheck %s
2
3; This will test whether or not the metadata from the current loop 1 latch
4; is removed, and applied to the new latch after running the loop-simplify
5; pass on this function. The loop simplify pass ensures that each loop has exit
6; blocks which only have predecessors that are inside of the loop. This
7; guarantees that the loop preheader/header will dominate the exit blocks. For
8; this function currently loop 2 does not have a dedicated exit block.
9
10; CHECK: loop_1_loopHeader.loopexit:
11; CHECK: br label %loop_1_loopHeader, !llvm.loop [[LOOP_1_LATCH_MD:![0-9]+]]
12; CHECK: loop_2_loopHeader
13; CHECK: br i1 %grt_B, label %loop_1_loopHeader.loopexit, label %loop_2_do
14; CHECK-NOT:  br i1 %grt_B, label %loop_1_loopHeader, label %loop_2_do, !llvm.loop{{.*}}
15
16define void @function(i32 %A) {
17entry:
18  %B = add i32 %A, 45
19  %C = add i32 %A, 22
20  br label %loop_1_loopHeader
21
22loop_1_loopHeader:                              ; preds = %loop_2_loopHeader, %entry
23  %loop_1_idx = phi i32 [ 1, %entry], [ %loop_1_update_idx, %loop_2_loopHeader ]
24  %grt_C = icmp slt i32 %loop_1_idx, %C
25  br i1 %grt_C, label %exit, label %loop_1_do
26
27loop_1_do:                                      ; preds = %loop_1_loopHeader
28  %loop_1_update_idx = add nuw nsw i32 %loop_1_idx, 1
29  br label %loop_2_loopHeader
30
31loop_2_loopHeader:                              ; preds = %loop_2_do, %_loop_1_do
32  %loop_2_idx = phi i32 [ 1, %loop_1_do ], [ %loop_2_update_idx, %loop_2_do ]
33  %grt_B = icmp slt i32 %loop_2_idx, %B
34  br i1 %grt_B, label %loop_1_loopHeader, label %loop_2_do, !llvm.loop !0
35
36loop_2_do:                                      ; preds = %loop_2_loopHeader
37  %loop_2_update_idx = add nuw nsw i32 %loop_2_idx, 1
38  br label %loop_2_loopHeader, !llvm.loop !2
39
40exit:                                       ; preds = %loop_1_loopHeader
41  ret void
42}
43
44!0 = distinct !{!0, !1}
45!1 = !{!"llvm.loop.unroll.disable"}
46!2 = distinct !{!2, !1}
47
48