xref: /llvm-project/llvm/test/Analysis/LoopAccessAnalysis/forward-loop-carried.ll (revision 17139f38e55ec06b8546b9306e04e64d0408033a)
1; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 4
2; RUN: opt -passes='print<access-info>' -disable-output  < %s 2>&1 | FileCheck %s
3
4;   for (unsigned i = 0; i < 100; i++) {
5;     A[i+8] = B[i] + 2;
6;     C[i] = A[i] * 2;
7;   }
8
9target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
10
11define void @forward_loop_carried(ptr noalias %A, ptr noalias %B, ptr noalias %C, i64 %N) {
12; CHECK-LABEL: 'forward_loop_carried'
13; CHECK-NEXT:    for.body:
14; CHECK-NEXT:      Memory dependences are safe
15; CHECK-NEXT:      Dependences:
16; CHECK-NEXT:        Forward:
17; CHECK-NEXT:            store i32 %a_p1, ptr %Aidx_ahead, align 4 ->
18; CHECK-NEXT:            %a = load i32, ptr %Aidx, align 4
19; CHECK-EMPTY:
20; CHECK-NEXT:      Run-time memory checks:
21; CHECK-NEXT:      Grouped accesses:
22; CHECK-EMPTY:
23; CHECK-NEXT:      Non vectorizable stores to invariant address were not found in loop.
24; CHECK-NEXT:      SCEV assumptions:
25; CHECK-EMPTY:
26; CHECK-NEXT:      Expressions re-written:
27;
28entry:
29  br label %for.body
30
31for.body:                                         ; preds = %for.body, %entry
32  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
33  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
34
35  %idx = add nuw nsw i64 %indvars.iv, 8
36
37  %Aidx_ahead = getelementptr inbounds i32, ptr %A, i64 %idx
38  %Bidx = getelementptr inbounds i32, ptr %B, i64 %indvars.iv
39  %Cidx = getelementptr inbounds i32, ptr %C, i64 %indvars.iv
40  %Aidx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv
41
42  %b = load i32, ptr %Bidx, align 4
43  %a_p1 = add i32 %b, 2
44  store i32 %a_p1, ptr %Aidx_ahead, align 4
45
46  %a = load i32, ptr %Aidx, align 4
47  %c = mul i32 %a, 2
48  store i32 %c, ptr %Cidx, align 4
49
50  %exitcond = icmp eq i64 %indvars.iv.next, %N
51  br i1 %exitcond, label %for.end, label %for.body
52
53for.end:                                          ; preds = %for.body
54  ret void
55}
56
57%struct = type { i8, [3 x i8], i32 }
58
59define void @forward_different_access_sizes(ptr readnone %end, ptr %start) {
60; CHECK-LABEL: 'forward_different_access_sizes'
61; CHECK-NEXT:    loop:
62; 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
63; CHECK-NEXT:  Forward loop carried data dependence that prevents store-to-load forwarding.
64; CHECK-NEXT:      Dependences:
65; CHECK-NEXT:        Forward:
66; CHECK-NEXT:            %l = load i24, ptr %gep.1, align 1 ->
67; CHECK-NEXT:            store i24 %l, ptr %ptr.iv, align 1
68; CHECK-EMPTY:
69; CHECK-NEXT:        ForwardButPreventsForwarding:
70; CHECK-NEXT:            store i32 0, ptr %gep.2, align 4 ->
71; CHECK-NEXT:            %l = load i24, ptr %gep.1, align 1
72; CHECK-EMPTY:
73; CHECK-NEXT:        Forward:
74; CHECK-NEXT:            store i32 0, ptr %gep.2, align 4 ->
75; CHECK-NEXT:            store i24 %l, ptr %ptr.iv, align 1
76; CHECK-EMPTY:
77; CHECK-NEXT:      Run-time memory checks:
78; CHECK-NEXT:      Grouped accesses:
79; CHECK-EMPTY:
80; CHECK-NEXT:      Non vectorizable stores to invariant address were not found in loop.
81; CHECK-NEXT:      SCEV assumptions:
82; CHECK-EMPTY:
83; CHECK-NEXT:      Expressions re-written:
84;
85entry:
86  br label %loop
87
88loop:
89  %ptr.iv = phi ptr [ %start, %entry ], [ %next, %loop ]
90  %gep.2  = getelementptr %struct, ptr %ptr.iv, i64 0, i32 2
91  store i32 0, ptr %gep.2, align 4
92  %gep.1 = getelementptr %struct, ptr %ptr.iv, i64 0, i32 1
93  %l = load i24, ptr %gep.1, align 1
94  store i24 %l, ptr %ptr.iv, align 1
95  %next = getelementptr inbounds %struct, ptr %ptr.iv, i64 1
96  %ec = icmp eq ptr %ptr.iv, %end
97  br i1 %ec, label %exit, label %loop
98
99exit:
100  ret void
101}
102