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<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I’m new to ScalarEvolution and wanted to explore its capabilities.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have following few questions:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">1) How to compare SCEV expressions.<o:p></o:p></p>
<p class="MsoNormal">I have a situation to compare two SCEV to find the min among them.
<o:p></o:p></p>
<p class="MsoNormal">Found an existing function(getMinFromExprs) in LoopAccessAnalysis which compares two SCEVs.<o:p></o:p></p>
<p class="MsoNormal">getMinFromExprs function finds the diff between two SCEV’s and then checks for the negative value to find the minimum.<o:p></o:p></p>
<p class="MsoNormal">While checking the negative value it specifically look for SCEVConstant.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Do we have anything to find the min in case of NON-SCEVConstant (with some additional information), i.e.:<o:p></o:p></p>
<p class="MsoNormal">SCEV1: (sext i32 (-1 + %n.addr.0) to i64)<o:p></o:p></p>
<p class="MsoNormal">SCEV2: 0<o:p></o:p></p>
<p class="MsoNormal">Extra information “n.addr.0 > 1” <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">2) How to feed the relational information to SCEV, i.e. “a > b”.<o:p></o:p></p>
<p class="MsoNormal">This relational information may not be explicitly available in the program.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">3) Is there any way in SCEV to force the compute(i.e. add) by ignore the cast(sext, zext, truc)<o:p></o:p></p>
<p class="MsoNormal">SCEV: (2 + (sext i32 (-1 + %n.addr.0) to i64))<o:p></o:p></p>
<p class="MsoNormal">After force addition expecting something like: “(1 + %n.addr.0)”<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any help by answer or pointers will be really useful.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">Ashutosh<o:p></o:p></p>
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