blob: 94080f05bde261c3d41c5c31acf34ef16769c59e [file] [log] [blame]
Adam Nemetc4866d22015-06-26 17:25:43 +00001; RUN: opt -basicaa -loop-accesses -analyze < %s | FileCheck %s
Sean Silva284b0322016-07-07 01:01:53 +00002; RUN: opt -passes='require<aa>,require<scalar-evolution>,require<aa>,loop(print-access-info)' -aa-pipeline='basic-aa' -disable-output < %s 2>&1 | FileCheck %s
Adam Nemetc4866d22015-06-26 17:25:43 +00003
4; For this loop:
5; for (int i = 0; i < n; i++)
6; A[2 * i] = A[2 * i] + B[i];
7;
8; , SCEV is unable to prove that A[2 * i] does not overflow. However,
9; analyzing the IR helps us to conclude it and in turn allow dependence
10; analysis.
11
12target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
13
14; CHECK: Memory dependences are safe{{$}}
15
16define void @f(i16* noalias %a,
17 i16* noalias %b, i64 %N) {
18entry:
19 br label %for.body
20
21for.body: ; preds = %for.body, %entry
22 %ind = phi i64 [ 0, %entry ], [ %inc, %for.body ]
23
24 %mul = mul nuw nsw i64 %ind, 2
25
26 %arrayidxA = getelementptr inbounds i16, i16* %a, i64 %mul
27 %loadA = load i16, i16* %arrayidxA, align 2
28
29 %arrayidxB = getelementptr inbounds i16, i16* %b, i64 %ind
30 %loadB = load i16, i16* %arrayidxB, align 2
31
32 %add = mul i16 %loadA, %loadB
33
34 store i16 %add, i16* %arrayidxA, align 2
35
36 %inc = add nuw nsw i64 %ind, 1
37 %exitcond = icmp eq i64 %inc, %N
38 br i1 %exitcond, label %for.end, label %for.body
39
40for.end: ; preds = %for.body
41 ret void
42}