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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Hi,<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">I'd be interested in an updated summary as well, especially any thoughts you have on when the various pieces might come online and where extra hands could be
helpful; we're eager to build our EH support in LLILC on top of this.<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">-Joseph<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"><a name="_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></a></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> llvmdev-bounces@cs.uiuc.edu [mailto:llvmdev-bounces@cs.uiuc.edu]
<b>On Behalf Of </b>Reid Kleckner<br>
<b>Sent:</b> Thursday, June 18, 2015 12:22 PM<br>
<b>To:</b> Philip Reames<br>
<b>Cc:</b> Nick Lewycky; LLVM Developers Mailing List<br>
<b>Subject:</b> Re: [LLVMdev] New EH representation for MSVC compatibility<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Wed, Jun 17, 2015 at 6:18 PM, Philip Reames <<a href="mailto:listmail@philipreames.com" target="_blank">listmail@philipreames.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal">Since I haven't been following the thread closely, is there an updated summary of the original proposal available? I know that various parts I had concerns with (the unsplitable blocks for instance) got addressed, but I'm having trouble
tracking all the changes in discussion. Even just a quick list of "and we changed X" would be helpful. <o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">We should do an updated summary, but I've been busy.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">We really do need to keep the unsplittable catchblocks, though. Fundamentally, what we have is control flow described by data. This proposal essentially adds LLVM instructions that model that data. We can't insert real instructions like
loads and stores between EH dispatch table entries, so it's forbidden.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">We can compensate for all the other CFG merging operations after the fact by duplicating code, but it's really hard to pattern match back EH dispatch once it's been allowed to round trip through memory, phis, GVN, etc.<o:p></o:p></p>
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