Adam Nemet | c4866d2 | 2015-06-26 17:25:43 +0000 | [diff] [blame] | 1 | ; RUN: opt -basicaa -loop-accesses -analyze < %s | FileCheck %s |
Sean Silva | 284b032 | 2016-07-07 01:01:53 +0000 | [diff] [blame] | 2 | ; 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 Nemet | c4866d2 | 2015-06-26 17:25:43 +0000 | [diff] [blame] | 3 | |
| 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 | |
| 12 | target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" |
| 13 | |
| 14 | ; CHECK: Memory dependences are safe{{$}} |
| 15 | |
| 16 | define void @f(i16* noalias %a, |
| 17 | i16* noalias %b, i64 %N) { |
| 18 | entry: |
| 19 | br label %for.body |
| 20 | |
| 21 | for.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 | |
| 40 | for.end: ; preds = %for.body |
| 41 | ret void |
| 42 | } |