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<div>Hi,</div>
<div> </div>
<div>I am trying to get the alias info for the following code. The alias analysis returns “MayAlias” for arrays “A” and “B” in both the functions instead of “NoAlias”. What passes should I run in opt before the alias analysis pass to get the accurate result?</div>
<div> </div>
<div><b>Example:</b></div>
<div> </div>
<div>//Note: static and called by func() only.</div>
<div>static int sum(int *A, int *B) {</div>
<div> </div>
<div> int i = 0, sum1 = 0;</div>
<div> </div>
<div> for (i = 0; i < 100; ++i) {</div>
<div> sum1 += A[i] + B[i];</div>
<div> }</div>
<div> return sum1;</div>
<div>}</div>
<div> </div>
<div>int func () {</div>
<div> int A[100], B[100];</div>
<div> int i = 0;</div>
<div> for (; i < 100; ++i) {</div>
<div> A[i] = B[i] = i;</div>
<div> }</div>
<div> return sum(A,B);</div>
<div>}</div>
<div> </div>
<div><b>Arguments to opt</b><b>: </b><b>“</b><b>-mem2reg -basicaa</b><b> </b><b>-</b><b>scev-aa </b><b> -print-alias-sets</b><b>”</b></div>
<div> </div>
<div><b>Output:</b></div>
<div><b>Function: func</b></div>
<div>Alias Set Tracker: 2 alias sets for 2 pointer values.</div>
<div> AliasSet[0x2bc88b0, 2] may alias, Mod/Ref Pointers: (i32* %A.arrayidx, 4), (i32* %B.arrayidx2, 4)</div>
<div> 1 Unknown instructions: i32 %call</div>
<div> AliasSet[0x2bc8490, 1] must alias, Mod forwarding to 0x2bc88b0</div>
<div> </div>
<div><b>Function: sum</b></div>
<div>Alias Set Tracker: 1 alias sets for 2 pointer values.</div>
<div> AliasSet[0x2bcbb50, 2] may alias, Ref Pointers: (i32* %A.arrayidx, 4), (i32* %B.arrayidx2, 4)</div>
<div> </div>
<div> </div>
<div>Thanks,</div>
<div>Vinay</div>
<div> </div>
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