xref: /llvm-project/llvm/test/Analysis/LoopAccessAnalysis/load-store-index-loaded-in-loop.ll (revision 844c188c7988f33e392cde06574d95dab3d0d60a)
1; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 5
2; RUN: opt -passes='print<access-info>' -disable-output %s 2>&1 | FileCheck %s
3
4; Test case for https://github.com/llvm/llvm-project/issues/87189.
5; It is not safe to vectorize because %indices are loaded in the loop and the
6; same indices could be loaded in later iterations.
7; FIXME: currently this is incorrectly considered safe for vectorization with
8; runtime checks
9define void @B_indices_loaded_in_loop_A_stored(ptr %A, ptr noalias %B, i64 %N, i64 %off) {
10; CHECK-LABEL: 'B_indices_loaded_in_loop_A_stored'
11; CHECK-NEXT:    loop:
12; CHECK-NEXT:      Report: unsafe dependent memory operations in loop. Use #pragma clang loop distribute(enable) to allow loop distribution to attempt to isolate the offending operations into a separate loop
13; CHECK-NEXT:  Unsafe indirect dependence.
14; CHECK-NEXT:      Dependences:
15; CHECK-NEXT:        IndirectUnsafe:
16; CHECK-NEXT:            %l = load i32, ptr %gep.B, align 4 ->
17; CHECK-NEXT:            store i32 %inc, ptr %gep.B, align 4
18; CHECK-EMPTY:
19; CHECK-NEXT:        Unknown:
20; CHECK-NEXT:            %indices = load i8, ptr %gep.A, align 1 ->
21; CHECK-NEXT:            store i32 %l, ptr %gep.C, align 4
22; CHECK-EMPTY:
23; CHECK-NEXT:      Run-time memory checks:
24; CHECK-NEXT:      Grouped accesses:
25; CHECK-EMPTY:
26; CHECK-NEXT:      Non vectorizable stores to invariant address were not found in loop.
27; CHECK-NEXT:      SCEV assumptions:
28; CHECK-EMPTY:
29; CHECK-NEXT:      Expressions re-written:
30;
31entry:
32  br label %loop
33
34loop:
35  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
36  %iv.off = add nuw nsw i64 %iv, %off
37  %gep.A = getelementptr inbounds i8, ptr %A, i64 %iv.off
38  %indices = load i8, ptr %gep.A, align 1
39  %indices.ext = zext i8 %indices to i64
40  %gep.B = getelementptr inbounds i32, ptr %B, i64 %indices.ext
41  %l = load i32, ptr %gep.B, align 4
42  %inc = add i32 %l, 1
43  store i32 %inc, ptr %gep.B, align 4
44  %gep.C = getelementptr inbounds i32, ptr %A, i64 %iv
45  store i32 %l, ptr %gep.C, align 4
46  %iv.next = add nuw nsw i64 %iv, 1
47  %ec = icmp eq i64 %iv.next, %N
48  br i1 %ec, label %exit, label %loop
49
50exit:
51  ret void
52}
53
54; It is not safe to vectorize because %indices are loaded in the loop and the
55; same indices could be loaded in later iterations.
56define void @B_indices_loaded_in_loop_A_not_stored(ptr %A, ptr noalias %B, i64 %N) {
57; CHECK-LABEL: 'B_indices_loaded_in_loop_A_not_stored'
58; CHECK-NEXT:    loop:
59; CHECK-NEXT:      Report: unsafe dependent memory operations in loop. Use #pragma clang loop distribute(enable) to allow loop distribution to attempt to isolate the offending operations into a separate loop
60; CHECK-NEXT:  Unsafe indirect dependence.
61; CHECK-NEXT:      Dependences:
62; CHECK-NEXT:        IndirectUnsafe:
63; CHECK-NEXT:            %l = load i32, ptr %gep.B, align 4 ->
64; CHECK-NEXT:            store i32 %inc, ptr %gep.B, align 4
65; CHECK-EMPTY:
66; CHECK-NEXT:      Run-time memory checks:
67; CHECK-NEXT:      Grouped accesses:
68; CHECK-EMPTY:
69; CHECK-NEXT:      Non vectorizable stores to invariant address were not found in loop.
70; CHECK-NEXT:      SCEV assumptions:
71; CHECK-EMPTY:
72; CHECK-NEXT:      Expressions re-written:
73;
74entry:
75  br label %loop
76
77loop:
78  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
79  %gep.A = getelementptr inbounds i8, ptr %A, i64 %iv
80  %indices = load i8, ptr %gep.A, align 1
81  %indices.ext = zext i8 %indices to i64
82  %gep.B = getelementptr inbounds i32, ptr %B, i64 %indices.ext
83  %l = load i32, ptr %gep.B, align 4
84  %inc = add i32 %l, 1
85  store i32 %inc, ptr %gep.B, align 4
86  %iv.next = add nuw nsw i64 %iv, 1
87  %ec = icmp eq i64 %iv.next, %N
88  br i1 %ec, label %exit, label %loop
89
90exit:
91  ret void
92}
93