<div dir="ltr">First of all, thank you for your input :) As many of you said, my question was somewhat vague. I'd like to clarify what we want to know, and what we did.<div><br><div><br></div><div>We're enumerating all the miscompilation bugs in the mem2reg and gvn passes (but not in the analysis passes they depend on), which was discovered after the release of LLVM 3.7.1 (5th Jan 2016).</div><div>That's why I specifically asked about the bugs in GVN.cpp and PromoteMemoryToRegister.cpp.</div><div><br></div><div>In order to know that, we searched "sroa", "mem2reg", "PromoteMemoryToRegister", and "gvn" in the LLVM bugzilla.</div><div>By manually inspecting the entire search result, we could find a handful of such bugs.</div><div><br></div><div>However, searching bugzilla may miss some bugs. A bug may not be reported in the bugzilla, but be patched in the trunk directly.</div><div>We'd like to know whether there are such bugs.</div><div><br></div><div><br></div><div>So I'd like to ask if you know any miscompilation bug that is (1) in PromoteMemoryToRegister.cpp or GVN.cpp; (2) discovered after the release of LLVM 3.7.1; <i>and</i> (3) not reported in the LLVM bugzilla.</div><div><br></div><div><br></div><div>I'm sorry that I asked a vague question. I hope this email clarifies my question. Also thank you again for valuable comments!</div><div><br></div><div>Best,</div><div>Jeehoon</div><div><br></div><div><br></div><div><br></div></div></div><div class="gmail_extra"><br><div class="gmail_quote">2018-04-11 4:21 GMT+09:00 Andrew Kelley via llvm-dev <span dir="ltr"><<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote"><span class="">On Tue, Apr 10, 2018 at 3:09 PM, Daniel Berlin via llvm-dev <span dir="ltr"><<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><br class="m_-5240701735633156494gmail-m_6564448605924352798gmail-Apple-interchange-newline"><br style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><div class="gmail_quote" style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><span class="m_-5240701735633156494gmail-">On Tue, Apr 10, 2018 at 10:28 AM, Friedman, Eli via llvm-dev<span> </span><span dir="ltr"><<a href="mailto:llvm-dev@lists.llvm.org" style="color:rgb(17,85,204)" target="_blank">llvm-dev@lists.llvm.<wbr>org</a>></span><span> </span>wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div bgcolor="#FFFFFF"><span class="m_-5240701735633156494gmail-m_6564448605924352798gmail-"><div class="m_-5240701735633156494gmail-m_6564448605924352798gmail-m_-7873523138089495954moz-cite-prefix">On 4/9/2018 8:19 PM, Jeehoon Kang via llvm-dev wrote:<br></div><blockquote type="cite"><div dir="ltr"><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">Dear llvm-dev,</div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><br></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><br></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">Hi! We're collecting mis-compilation bugs in gvn and mem2reg since 3.7.1. Specifically, We're interested in bugs in the following files:</div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><br></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">llvm/lib/Transforms/Scalar/</span><span class="m_-5240701735633156494gmail-m_6564448605924352798gmail-m_-7873523138089495954gmail-m_-7780041005970198807gmail-il" style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">GVN</span><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline"><wbr>.</span><span class="m_-5240701735633156494gmail-m_6564448605924352798gmail-m_-7873523138089495954gmail-m_-7780041005970198807gmail-il" style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">cpp</span><span> </span><br></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">llvm/lib/Transforms/Utils/Prom<wbr>oteMemoryToRegister.<span class="m_-5240701735633156494gmail-m_6564448605924352798gmail-m_-7873523138089495954gmail-m_-7780041005970198807gmail-il">cpp</span></div></div></div></blockquote><br></span>3.7 was released over two years ago; there have been many bugfixes to both GVN and the analysis passes it depends on since then. Do you have some idea of what, specifically, you're looking for?<br><br>mem2reg is a very simple pass; I would be surprised if you found miscompile bug in it.<br></div></blockquote><div><br></div></span><div>There are definitely a few miscompile bugs floating around in the edge cases of mem2reg.</div></div></div></blockquote><div><br></div></span><div>Here's one: <a href="https://bugs.llvm.org/show_bug.cgi?id=36578" target="_blank">https://bugs.llvm.org/show_<wbr>bug.cgi?id=36578</a><br></div><span class=""><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_quote" style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><div><br></div></div></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div class="m_-5240701735633156494gmail-h5">On Tue, Apr 10, 2018 at 10:28 AM, Friedman, Eli via llvm-dev <span dir="ltr"><<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div><div class="m_-5240701735633156494gmail-h5">
<div bgcolor="#FFFFFF"><span>
<div class="m_-5240701735633156494gmail-m_6564448605924352798m_-7873523138089495954moz-cite-prefix">On 4/9/2018 8:19 PM, Jeehoon Kang via
llvm-dev wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">Dear
llvm-dev,</div>
<div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><br>
</div>
<div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><br>
</div>
<div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">Hi!
We're collecting mis-compilation bugs in gvn and mem2reg since
3.7.1. Specifically, We're interested in bugs in the
following files:</div>
<div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><br>
</div>
<div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">llvm/lib/Transforms/Scalar/</span><span class="m_-5240701735633156494gmail-m_6564448605924352798m_-7873523138089495954gmail-m_-7780041005970198807gmail-il" style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">GVN</span><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline"><wbr>.</span><span class="m_-5240701735633156494gmail-m_6564448605924352798m_-7873523138089495954gmail-m_-7780041005970198807gmail-il" style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">cpp</span><span> </span><br>
</div>
<div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">
<div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial">llvm/lib/Transforms/Utils/Prom<wbr>oteMemoryToRegister.<span class="m_-5240701735633156494gmail-m_6564448605924352798m_-7873523138089495954gmail-m_-7780041005970198807gmail-il">cpp</span></div>
</div>
</div>
</blockquote>
<br></span>
3.7 was released over two years ago; there have been many bugfixes
to both GVN and the analysis passes it depends on since then. Do
you have some idea of what, specifically, you're looking for?<br>
<br>
mem2reg is a very simple pass; I would be surprised if you found
miscompile bug in it.<br>
<br>
-Eli<span class="m_-5240701735633156494gmail-m_6564448605924352798HOEnZb"><font color="#888888"><br>
<pre class="m_-5240701735633156494gmail-m_6564448605924352798m_-7873523138089495954moz-signature" cols="72">--
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project</pre>
</font></span></div>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><a href="http://sf.snu.ac.kr/jeehoon.kang" target="_blank">Jeehoon Kang (Ph.D. student)</a><div><a href="http://sf.snu.ac.kr" target="_blank">Software Foundations Laboratory</a><div><a href="http://www.snu.ac.kr" target="_blank">Seoul National University</a></div></div></div></div>
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