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<div class="moz-cite-prefix">On 10/24/2014 01:17 PM, Artem Dinaburg
wrote:<br>
</div>
<blockquote
cite="mid:1E303223-D403-4FEA-90E2-FAD0D95092F3@trailofbits.com"
type="cite">
<pre wrap="">Hi,
It looks like the DeadStoreElimination optimization doesn't work across BasicBlock boundaries. The project I'm working on (<a class="moz-txt-link-freetext" href="https://github.com/trailofbits/mcsema">https://github.com/trailofbits/mcsema</a>), would tremendously benefit from even simple cross-block DSE. </pre>
</blockquote>
If you have specific small examples which aren't getting caught, I'd
be interested in seeing test cases (as bugs.)
<blockquote
cite="mid:1E303223-D403-4FEA-90E2-FAD0D95092F3@trailofbits.com"
type="cite">
<pre wrap="">There was a patch to do non-local DSE few years ago (<a class="moz-txt-link-freetext" 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.
Is there an existing way to do cross-block DSE?</pre>
</blockquote>
EarlyCSE handles limited cases here. GVN probably could, but
doesn't seem to. (Which surprises me.)<br>
<blockquote
cite="mid:1E303223-D403-4FEA-90E2-FAD0D95092F3@trailofbits.com"
type="cite">
<pre wrap="">Was there something wrong with the original non-local DSE patch that it wasn't merged?</pre>
</blockquote>
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>
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cite="mid:1E303223-D403-4FEA-90E2-FAD0D95092F3@trailofbits.com"
type="cite">
<pre wrap="">
Thanks,
Artem
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</pre>
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