1 ; RUN: opt -basicaa -loop-accesses -analyze < %s | FileCheck %s 2 3 ; For this loop: 4 ; for (int i = 0; i < n; i++) 5 ; A[2 * i] = A[2 * i] + B[i]; 6 ; 7 ; , SCEV is unable to prove that A[2 * i] does not overflow. However, 8 ; analyzing the IR helps us to conclude it and in turn allow dependence 9 ; analysis. 10 11 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" 12 13 ; CHECK: Memory dependences are safe{{$}} 14 15 define void @f(i16* noalias %a, 16 i16* noalias %b, i64 %N) { 17 entry: 18 br label %for.body 19 20 for.body: ; preds = %for.body, %entry 21 %ind = phi i64 [ 0, %entry ], [ %inc, %for.body ] 22 23 %mul = mul nuw nsw i64 %ind, 2 24 25 %arrayidxA = getelementptr inbounds i16, i16* %a, i64 %mul 26 %loadA = load i16, i16* %arrayidxA, align 2 27 28 %arrayidxB = getelementptr inbounds i16, i16* %b, i64 %ind 29 %loadB = load i16, i16* %arrayidxB, align 2 30 31 %add = mul i16 %loadA, %loadB 32 33 store i16 %add, i16* %arrayidxA, align 2 34 35 %inc = add nuw nsw i64 %ind, 1 36 %exitcond = icmp eq i64 %inc, %N 37 br i1 %exitcond, label %for.end, label %for.body 38 39 for.end: ; preds = %for.body 40 ret void 41 } 42
