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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><a href="http://llvm.org/bugs/show_bug.cgi?id=5625">http://llvm.org/bugs/show_bug.cgi?id=5625</a><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Thanks,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Balaram<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> llvmdev-bounces@cs.uiuc.edu [mailto:llvmdev-bounces@cs.uiuc.edu] <b>On Behalf Of </b>Philip Reames<br><b>Sent:</b> Wednesday, November 05, 2014 7:48 PM<br><b>To:</b> Artem Dinaburg; llvmdev@cs.uiuc.edu<br><b>Subject:</b> Re: [LLVMdev] Cross-Block Dead Store Elimination<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>On 10/24/2014 01:17 PM, Artem Dinaburg wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><pre>Hi,<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>It looks like the DeadStoreElimination optimization doesn't work across BasicBlock boundaries. The project I'm working on (<a href="https://github.com/trailofbits/mcsema">https://github.com/trailofbits/mcsema</a>), would tremendously benefit from even simple cross-block DSE. <o:p></o:p></pre></blockquote><p class=MsoNormal>If you have specific small examples which aren't getting caught, I'd be interested in seeing test cases (as bugs.) <o:p></o:p></p><pre>There was a patch to do non-local DSE few years ago (<a href="http://lists.cs.uiuc.edu/pipermail/llvmdev/2010-January/028751.html">http://lists.cs.uiuc.edu/pipermail/llvmdev/2010-January/028751.html</a>), but seems that the patch was never merged.<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Is there an existing way to do cross-block DSE?<o:p></o:p></pre><p class=MsoNormal>EarlyCSE handles limited cases here. GVN probably could, but doesn't seem to. (Which surprises me.)<br><br><o:p></o:p></p><pre>Was there something wrong with the original non-local DSE patch that it wasn't merged?<o:p></o:p></pre><p class=MsoNormal>I suspect it got lost in review. It looks like there were some quality issues with the original implementation and the cycle never got closed.<br><br><o:p></o:p></p><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre>Thanks,<o:p></o:p></pre><pre>Artem<o:p></o:p></pre><p class=MsoNormal><br><br><br><o:p></o:p></p><pre>_______________________________________________<o:p></o:p></pre><pre>LLVM Developers mailing list<o:p></o:p></pre><pre><a href="mailto:LLVMdev@cs.uiuc.edu">LLVMdev@cs.uiuc.edu</a> <a href="http://llvm.cs.uiuc.edu">http://llvm.cs.uiuc.edu</a><o:p></o:p></pre><pre><a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev</a><o:p></o:p></pre><p class=MsoNormal><o:p> </o:p></p></div></body></html>