xref: /llvm-project/llvm/test/Analysis/LoopAccessAnalysis/pointer-with-unknown-bounds.ll (revision 844c188c7988f33e392cde06574d95dab3d0d60a)
1; RUN: opt -aa-pipeline=basic-aa -passes='print<access-info>' -disable-output  < %s 2>&1 | FileCheck %s
2
3target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
4
5; We shouldn't quit the analysis if we encounter a pointer without known
6; bounds *unless* we actually need to emit a memcheck for it.  (We only
7; compute bounds for SCEVAddRecs so A[i*i] is deemed not having known bounds.)
8;
9; for (i = 0; i < 20; ++i)
10;   A[i*i] *= 2;
11
12; CHECK-LABEL: addrec_squared
13; CHECK-NEXT: for.body:
14; CHECK-NEXT:   Report: unsafe dependent memory operations in loop
15; CHECK-NOT:    Report: cannot identify array bounds
16; CHECK-NEXT:   Unsafe indirect dependence.
17; CHECK-NEXT:     Dependences:
18; CHECK-NEXT:       IndirectUnsafe:
19; CHECK-NEXT:         %loadA = load i16, ptr %arrayidxA, align 2 ->
20; CHECK-NEXT:         store i16 %mul, ptr %arrayidxA, align 2
21
22define void @addrec_squared(ptr %a) {
23entry:
24  br label %for.body
25
26for.body:                                         ; preds = %for.body, %entry
27  %ind = phi i64 [ 0, %entry ], [ %add, %for.body ]
28
29  %access_ind = mul i64 %ind, %ind
30
31  %arrayidxA = getelementptr inbounds i16, ptr %a, i64 %access_ind
32  %loadA = load i16, ptr %arrayidxA, align 2
33
34  %mul = mul i16 %loadA, 2
35
36  store i16 %mul, ptr %arrayidxA, align 2
37
38  %add = add nuw nsw i64 %ind, 1
39  %exitcond = icmp eq i64 %add, 20
40  br i1 %exitcond, label %for.end, label %for.body
41
42for.end:                                          ; preds = %for.body
43  ret void
44}
45
46; TODO: We cannot compute the bound for %arrayidxA_ub, because the index is
47; loaded on each iteration. As %a and %b are no-alias, no memchecks are required
48; and unknown bounds should not prevent further analysis.
49define void @loaded_bound(ptr noalias %a, ptr noalias %b) {
50; CHECK-LABEL: loaded_bound
51; CHECK-NEXT:  for.body:
52; CHECK-NEXT:    Report: cannot identify array bounds
53; CHECK-NEXT:    Dependences:
54; CHECK-NEXT:    Run-time memory checks:
55
56entry:
57  br label %for.body
58
59for.body:                                         ; preds = %for.body, %entry
60  %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.body ]
61
62  %iv.next = add nuw nsw i64 %iv, 1
63
64  %arrayidxB = getelementptr inbounds i16, ptr %b, i64 %iv
65  %loadB = load i16, ptr %arrayidxB, align 2
66
67  %arrayidxA_ub = getelementptr inbounds i16, ptr %a, i16 %loadB
68  %loadA_ub = load i16, ptr %arrayidxA_ub, align 2
69
70  %mul = mul i16 %loadB, %loadA_ub
71
72  %arrayidxA = getelementptr inbounds i16, ptr %a, i64 %iv
73  store i16 %mul, ptr %arrayidxA, align 2
74
75  %exitcond = icmp eq i64 %iv, 20
76  br i1 %exitcond, label %for.end, label %for.body
77
78for.end:                                          ; preds = %for.body
79  ret void
80}
81