1; RUN: opt < %s -force-vector-interleave=1 -store-to-load-forwarding-conflict-detection=false -loop-vectorize -dce -instcombine -S | FileCheck %s
2
3target datalayout = "e-m:e-i64:64-i128:128-n32:64-S128"
4target triple = "aarch64--linux-gnu"
5
6%struct.pair = type { i32, i32 }
7
8; Check vectorization of interleaved access groups with positive dependence
9; distances. In this test, the maximum safe dependence distance for
10; vectorization is 16 bytes. Normally, this would lead to a maximum VF of 4.
11; However, for interleaved groups, the effective VF is VF * IF, where IF is the
12; interleave factor. Here, the maximum safe dependence distance is recomputed
13; as 16 / IF bytes, resulting in VF=2. Since IF=2, we should generate <4 x i32>
14; loads and stores instead of <8 x i32> accesses.
15;
16; Note: LAA's conflict detection optimization has to be disabled for this test
17;       to be vectorized.
18
19; struct pair {
20;   int x;
21;   int y;
22; };
23;
24; void max_vf(struct pair *restrict p) {
25;   for (int i = 0; i < 1000; i++) {
26;     p[i + 2].x = p[i].x
27;     p[i + 2].y = p[i].y
28;   }
29; }
30
31; CHECK-LABEL: @max_vf
32; CHECK: load <4 x i32>
33; CHECK: store <4 x i32>
34
35define void @max_vf(%struct.pair* noalias nocapture %p) {
36entry:
37  br label %for.body
38
39for.body:
40  %i = phi i64 [ 0, %entry ], [ %i.next, %for.body ]
41  %0 = add nuw nsw i64 %i, 2
42  %p_i.x = getelementptr inbounds %struct.pair, %struct.pair* %p, i64 %i, i32 0
43  %p_i_plus_2.x = getelementptr inbounds %struct.pair, %struct.pair* %p, i64 %0, i32 0
44  %1 = load i32, i32* %p_i.x, align 4
45  store i32 %1, i32* %p_i_plus_2.x, align 4
46  %p_i.y = getelementptr inbounds %struct.pair, %struct.pair* %p, i64 %i, i32 1
47  %p_i_plus_2.y = getelementptr inbounds %struct.pair, %struct.pair* %p, i64 %0, i32 1
48  %2 = load i32, i32* %p_i.y, align 4
49  store i32 %2, i32* %p_i_plus_2.y, align 4
50  %i.next = add nuw nsw i64 %i, 1
51  %cond = icmp eq i64 %i.next, 1000
52  br i1 %cond, label %for.exit, label %for.body
53
54for.exit:
55  ret void
56}
57