1; RUN: opt -basic-aa -loop-distribute -enable-loop-distribute -S < %s | FileCheck %s
2
3; When emitting the memchecks for:
4;
5;   for (i = 0; i < n; i++) {
6;     A[i + 1] = A[i] * B[i];
7;     =======================
8;     C[i] = D[i] * E[i];
9;   }
10;
11; we had a bug when expanding the bounds for A and C.  These are expanded
12; multiple times and rely on the caching in SCEV expansion to avoid any
13; redundancy.  However, due to logic in SCEVExpander::ReuseOrCreateCast, we
14; can get earlier expanded values invalidated when casts are used.  This test
15; ensure that we are not using the invalidated values.
16
17target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
18
19define void @f(i32* %a1, i32* %a2,
20               i32* %b,
21               i32* %c1, i32* %c2,
22               i32* %d,
23               i32* %e) {
24entry:
25
26  %cond = icmp eq i32* %e, null
27  br i1 %cond, label %one, label %two
28one:
29  br label %join
30two:
31  br label %join
32join:
33
34; The pointers need to be defined by PHIs in order for the bug to trigger.
35; Because of the PHIs the existing casts won't be at the desired location so a
36; new cast will be emitted and the old cast will get invalidated.
37;
38; These are the steps:
39;
40; 1. After the bounds for A and C are first expanded:
41;
42;   join:
43;     %a = phi i32* [ %a1, %one ], [ %a2, %two ]
44;     %c = phi i32* [ %c1, %one ], [ %c2, %two ]
45;     %c5 = bitcast i32* %c to i8*
46;     %a3 = bitcast i32* %a to i8*
47;
48; 2. After A is expanded again:
49;
50;   join:                                             ; preds = %two, %one
51;     %a = phi i32* [ %a1, %one ], [ %a2, %two ]
52;     %c = phi i32* [ %c1, %one ], [ %c2, %two ]
53;     %a3 = bitcast i32* %a to i8*                   <--- new
54;     %c5 = bitcast i32* %c to i8*
55;     %0 = bitcast i32* %a to i8*                 <--- old, invalidated
56;
57; 3. Finally, when C is expanded again:
58;
59;   join:                                             ; preds = %two, %one
60;     %a = phi i32* [ %a1, %one ], [ %a2, %two ]
61;     %c = phi i32* [ %c1, %one ], [ %c2, %two ]
62;     %c5 = bitcast i32* %c to i8*                   <--- new
63;     %a3 = bitcast i32* %a to i8*
64;     %0 = bitcast i32* %c to i8*                 <--- old, invalidated
65;     %1 = bitcast i32* %a to i8*
66
67  %a = phi i32* [%a1, %one], [%a2, %two]
68  %c = phi i32* [%c1, %one], [%c2, %two]
69  br label %for.body
70
71; CHECK: join
72; CHECK: {{%[0-9a-z]+}} = bitcast i32* %a to i8*
73; CHECK: {{%[0-9a-z]+}} = bitcast i32* %c to i8*
74; CHECK-NOT: bitcast i32* %c to i8*
75; CHECK-NOT: bitcast i32* %a to i8*
76
77for.body:                                         ; preds = %for.body, %entry
78  %ind = phi i64 [ 0, %join ], [ %add, %for.body ]
79
80  %arrayidxA = getelementptr inbounds i32, i32* %a, i64 %ind
81  %loadA = load i32, i32* %arrayidxA, align 4
82
83  %arrayidxB = getelementptr inbounds i32, i32* %b, i64 %ind
84  %loadB = load i32, i32* %arrayidxB, align 4
85
86  %mulA = mul i32 %loadB, %loadA
87
88  %add = add nuw nsw i64 %ind, 1
89  %arrayidxA_plus_4 = getelementptr inbounds i32, i32* %a, i64 %add
90  store i32 %mulA, i32* %arrayidxA_plus_4, align 4
91
92  %arrayidxD = getelementptr inbounds i32, i32* %d, i64 %ind
93  %loadD = load i32, i32* %arrayidxD, align 4
94
95  %arrayidxE = getelementptr inbounds i32, i32* %e, i64 %ind
96  %loadE = load i32, i32* %arrayidxE, align 4
97
98  %mulC = mul i32 %loadD, %loadE
99
100  %arrayidxC = getelementptr inbounds i32, i32* %c, i64 %ind
101  store i32 %mulC, i32* %arrayidxC, align 4
102
103  %exitcond = icmp eq i64 %add, 20
104  br i1 %exitcond, label %for.end, label %for.body
105
106for.end:                                          ; preds = %for.body
107  ret void
108}
109