<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">    I see 3 options to address my problem:<br>
      - implement a case that handles this in PHI elimination (PHIElimination.cpp);<br>
      - create a new pass that does copy propagation (based on DFA) on machine instructions before Register Allocation;<br>
      - optimize copy coalescing such as the standard one or the one activated by -pbqp-coalescing in lib/CodeGen/RegAllocPBQP.cpp (there is an email also about PBQP coalescing at <a href="http://lists.llvm.org/pipermail/llvm-dev/2016-June/100523.html" rel="noreferrer" target="_blank">http://lists.llvm.org/pipermai<wbr>l/llvm-dev/2016-June/100523.<wbr>html</a>).<br></blockquote><div><br></div><div><span style="font-family:arial,helvetica,sans-serif">Usually this is done by </span><span style="font-size:14px">copy coalescing, do you know why yours cannot be eliminated, </span><span style="font-size:14px">is your case not be handled well in existing </span><span style="font-size:14px">copy coalescing</span><span style="font-size:14px"> (</span><span style="font-size:14px">RegisterCoalescer.cpp for example</span><span style="font-size:14px">)?</span><span style="font-size:14px"> </span> </div></div><br><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">​HTH,</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">chenwj​</div><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr"><div>Wei-Ren Chen (陳韋任)<br>Homepage: <a href="https://people.cs.nctu.edu.tw/~chenwj" target="_blank">https://people.cs.nctu.edu.tw/~chenwj</a></div></div></div>
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