1; RUN: opt -basicaa -loop-accesses -analyze < %s | FileCheck %s 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 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 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} 43