<div dir="ltr"><div dir="ltr"><div class="gmail_default" style="font-family:verdana,sans-serif"><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Feb 11, 2021 at 8:30 AM Liu, Yaxun (Sam) <<a href="mailto:Yaxun.Liu@amd.com">Yaxun.Liu@amd.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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<p class="gmail-m_8197267415497547112msipheader251902e5" style="margin:0in"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(49,113,0)">[AMD Public Use]</span><u></u><u></u></p>
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<p class="MsoNormal">Sorry for the delay.<u></u><u></u></p>
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<p class="MsoNormal">Both Johannes’ and Artem’s proposals should satisfy the needs of users:<u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:Verdana,sans-serif">Option 1:<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-family:Verdana,sans-serif">`-offload=<offload-pattern> optA optB optC`. <u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-family:Verdana,sans-serif">Option 2:<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-family:Verdana,sans-serif">`-offload=<offload-pattern>,optA,optB,optC`. </span></p></div></div></blockquote><div><br></div><div><div class="gmail_default" style="font-family:verdana,sans-serif">I'm fine with #2. We're using something similar with our build tools and it works reasonably well.</div><div class="gmail_default" style="font-family:verdana,sans-serif">However, it does have one annoying corner case. There's no easy way to pass an option which has a comma in it. E.g. if I want to pass `-Wl,something,something`. Perhaps we could use sed-like approach and allow changing the separator. E.g. `s/a/b/` == `s@a@b@`.</div><br></div><div><div class="gmail_default" style="font-family:verdana,sans-serif">--Artem</div><br></div><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 lang="EN-US" style="overflow-wrap: break-word;"><div class="gmail-m_8197267415497547112WordSection1"><p class="MsoNormal"><span style="font-family:Verdana,sans-serif"><u></u><u></u></span></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Compared to the old options, they are more concise and more readable.<u></u><u></u></p>
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<p class="MsoNormal">The main difference is the delimiter. To me option 2 is more attractive since it does not need quotations for most cases.<u></u><u></u></p>
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<p class="MsoNormal">Can we reach an agreement on option 2?<u></u><u></u></p>
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<p class="MsoNormal">Thanks.<u></u><u></u></p>
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<p class="MsoNormal">Sam<u></u><u></u></p>
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<p class="MsoNormal"><b>From:</b> Artem Belevich <<a href="mailto:tra@google.com" target="_blank">tra@google.com</a>> <br>
<b>Sent:</b> Tuesday, December 15, 2020 2:13 PM<br>
<b>To:</b> Ben Boeckel <<a href="mailto:ben.boeckel@kitware.com" target="_blank">ben.boeckel@kitware.com</a>><br>
<b>Cc:</b> Doerfert, Johannes <<a href="mailto:jdoerfert@anl.gov" target="_blank">jdoerfert@anl.gov</a>>; Liu, Yaxun (Sam) <<a href="mailto:Yaxun.Liu@amd.com" target="_blank">Yaxun.Liu@amd.com</a>>; Lieberman, Ron <<a href="mailto:Ron.Lieberman@amd.com" target="_blank">Ron.Lieberman@amd.com</a>>; <a href="mailto:a.bataev@hotmail.com" target="_blank">a.bataev@hotmail.com</a>; Chan, SiuChi <<a href="mailto:siuchi.chan@amd.com" target="_blank">siuchi.chan@amd.com</a>>; Searles, Mark <<a href="mailto:Mark.Searles@amd.com" target="_blank">Mark.Searles@amd.com</a>>; cfe-dev (<a href="mailto:cfe-dev@lists.llvm.org" target="_blank">cfe-dev@lists.llvm.org</a>)
<<a href="mailto:cfe-dev@lists.llvm.org" target="_blank">cfe-dev@lists.llvm.org</a>><br>
<b>Subject:</b> Re: [cfe-dev] [RFC] Unified offloading option for CUDA/HIP/OpenMP<u></u><u></u></p>
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<p class="MsoNormal">[CAUTION: External Email] <u></u><u></u></p>
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<p class="MsoNormal">On Tue, Dec 15, 2020 at 10:23 AM Ben Boeckel <<a href="mailto:ben.boeckel@kitware.com" target="_blank">ben.boeckel@kitware.com</a>> wrote:<u></u><u></u></p>
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<p class="MsoNormal">On Mon, Dec 14, 2020 at 14:04:43 -0800, Artem Belevich via cfe-dev wrote:<br>
> It all may be an utter overkill, too. WDYT?<br>
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Note that tools such as ccache and sccache generally need to be able to<br>
understand what's going on (I believe distcc and other distributed<br>
compilation tools also generally need to know too), so making it<br>
sensible enough for interpretation based on just the flags to be<br>
possible should be considered.<u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:Arial,sans-serif">I think this is somewhat orthogonal to how we specify per-target options. Such a tool almost never knows about all possible compiler options and has to pass through the unknown options as-is. However,
any form of 'nested' options specified on the command line will have a chance to confuse such
</span><span style="font-family:Verdana,sans-serif">tool</span><span style="font-family:Arial,sans-serif">. E.g.
</span><span style="font-family:Verdana,sans-serif">if I</span><span style="font-family:Arial,sans-serif"> want to pass '-E' to some sub-tool for a particular offload-target, ccache, not being aware that it's not a top-level compilation option, may interpret
it as an attempt to preprocess the TU.</span><span style="font-family:Verdana,sans-serif"><u></u><u></u></span></p>
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<p class="MsoNormal">I wonder if it would make sense to just move all this per-target option complexity into an external response file. As far as existing tools are concerned, it would look like `--offload-options=target-opts.file` without affecting tool's
general idea what this compilation is about to do, and the external file would allow us to be as flexible as we need to be to specify per-target options. It could be just a flat list of pairs `-Xarch_... optA`. Or we could use YAML. <u></u><u></u></p>
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<p class="MsoNormal">That approach, however, has its own issues and would still need to be optional. If it's the only way to specify offload options, that will complicate other use cases as now they would have to deal with temporary files.<u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:Verdana,sans-serif">Maybe a slightly modified variant of jdoefert@'s idea would work better:<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-family:Arial,sans-serif;color:rgb(80,0,80)">> >> -offload="amd -march=gfx906 -fno-vectorize" -fopenmp</span><span style="font-family:Verdana,sans-serif"><u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-family:Verdana,sans-serif">Implement it in a way similar to -Wl,optA,optB,optC and extend it to match an offload scope glob/regex.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-family:Verdana,sans-serif">E.g. `-offload=<offload-pattern>,optA,optB,optC`. <u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-family:Verdana,sans-serif">As far as the external tools are concerned, it's just one option to pass though. At the same time it should be flexible enough to apply the options to subset of offload targets in a human-manageable
way.<u></u><u></u></span></p>
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<p class="MsoNormal">-- <u></u><u></u></p>
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<p class="MsoNormal">--Artem Belevich<u></u><u></u></p>
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</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr">--Artem Belevich</div></div></div>