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- ; RUN: opt -basicaa -loop-accesses -analyze < %s | FileCheck %s
- ; For this loop:
- ; for (int i = 0; i < n; i++)
- ; A[2 * i] = A[2 * i] + B[i];
- ;
- ; , SCEV is unable to prove that A[2 * i] does not overflow. However,
- ; analyzing the IR helps us to conclude it and in turn allow dependence
- ; analysis.
- target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
- ; CHECK: Memory dependences are safe{{$}}
- define void @f(i16* noalias %a,
- i16* noalias %b, i64 %N) {
- entry:
- br label %for.body
- for.body: ; preds = %for.body, %entry
- %ind = phi i64 [ 0, %entry ], [ %inc, %for.body ]
- %mul = mul nuw nsw i64 %ind, 2
- %arrayidxA = getelementptr inbounds i16, i16* %a, i64 %mul
- %loadA = load i16, i16* %arrayidxA, align 2
- %arrayidxB = getelementptr inbounds i16, i16* %b, i64 %ind
- %loadB = load i16, i16* %arrayidxB, align 2
- %add = mul i16 %loadA, %loadB
- store i16 %add, i16* %arrayidxA, align 2
- %inc = add nuw nsw i64 %ind, 1
- %exitcond = icmp eq i64 %inc, %N
- br i1 %exitcond, label %for.end, label %for.body
- for.end: ; preds = %for.body
- ret void
- }
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