safe-with-dep-distance.ll
1.16 KB
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; RUN: opt -loop-accesses -analyze < %s | FileCheck %s
; RUN: opt -passes='require<scalar-evolution>,require<aa>,loop(print-access-info)' -disable-output < %s 2>&1 | FileCheck %s
; Analyze this loop:
; for (i = 0; i < n; i++)
; A[i + 4] = A[i] * 2;
; CHECK: Memory dependences are safe with a maximum dependence distance of 8 bytes
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.10.0"
@A = common global i16* null, align 8
define void @f() {
entry:
%a = load i16*, i16** @A, align 8
br label %for.body
for.body: ; preds = %for.body, %entry
%ind = phi i64 [ 0, %entry ], [ %add, %for.body ]
%arrayidxA = getelementptr inbounds i16, i16* %a, i64 %ind
%loadA = load i16, i16* %arrayidxA, align 2
%mul = mul i16 %loadA, 2
%next = add nuw nsw i64 %ind, 4
%arrayidxA_next = getelementptr inbounds i16, i16* %a, i64 %next
store i16 %mul, i16* %arrayidxA_next, align 2
%add = add nuw nsw i64 %ind, 1
%exitcond = icmp eq i64 %add, 20
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body
ret void
}