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<p class="MsoNormal">Hi all,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The AArch64->ARM64 merge is progressing at a rapid pace. Below I have taken the requirements drawn up in Edinburgh (which were sent to the list for comment) and annotated them with the current progress.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The TL;DR is that we still have a couple of issues outstanding but we’re well on track for removing AArch64 (and re-bikeshedding ARM64) for the 3.5 release!<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Times are incredibly approximate and are in man-days/weeks.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Requirement: No regressions<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l0 level2 lfo1">
<![if !supportLists]><span style="font-family:"Courier New""><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Correctness<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[2w]</b> Regression tests<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:144.0pt;text-indent:-18.0pt;mso-list:l0 level4 lfo1">
<![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>All AArch64 Clang regression tests in Driver/, Sema/, Basic/ and Preprocessor/ ported. Only those in CodeGen{,CXX}/ left.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:144.0pt;text-indent:-18.0pt;mso-list:l0 level4 lfo1">
<![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Most LLVM regression tests ported. A couple of more intricate tests remain, along with the MC tests which may be a headache to dig through.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[?] </b>QuIC internal tests<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:144.0pt;text-indent:-18.0pt;mso-list:l0 level4 lfo1">
<![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Nightly runs show 11 test failures. Some compile-time (front-end issues), link-time and runtime (miscomparison) failures too.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[2d]</b> ARM internal tests<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:144.0pt;text-indent:-18.0pt;mso-list:l0 level4 lfo1">
<![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>All our test suites apart from Emperor and Perennial are passing.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:144.0pt;text-indent:-18.0pt;mso-list:l0 level4 lfo1">
<![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Emperor mentioned below, Perennial runs ongoing.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[0d] </b>Apple internal tests<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:144.0pt;text-indent:-18.0pt;mso-list:l0 level4 lfo1">
<![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Tim says we’re “looking reasonable” here <span style="font-family:Wingdings">
J</span><o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:144.0pt;text-indent:-18.0pt;mso-list:l0 level4 lfo1">
<![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>This only blocks a “go/no-go”, and there are no actual actions here at the moment (according to Tim)<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[DONE] </b>LLVM test suite<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[1d]</b> MC Hammer<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:144.0pt;text-indent:-18.0pt;mso-list:l0 level4 lfo1">
<![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>One issue with aliasing remains. Patch being sent out to the list Friday.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[3d] </b>Emperor<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:144.0pt;text-indent:-18.0pt;mso-list:l0 level4 lfo1">
<![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>One issue still outstanding. Patch being sent to the list very shortly.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:144.0pt;text-indent:-18.0pt;mso-list:l0 level4 lfo1">
<![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>This is a random test suite so has the possibility to uncover more problems. Our acceptance criterion is 3 days runtime without finding any bugs.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l0 level2 lfo1">
<![if !supportLists]><span style="font-family:"Courier New""><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Performance<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>No precise fixed performance baseline<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[DONE] </b>Investigate significant performance regressions – justify fix/not fix.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:144.0pt;text-indent:-18.0pt;mso-list:l0 level4 lfo1">
<![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>No performance blockers reported.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Requirement: Feature parity<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l0 level2 lfo1">
<![if !supportLists]><span style="font-family:"Courier New""><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[1-2w]</b> Big endian<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>This comes in two parts. Big endian support with no NEON is almost completely ported – the last patches are being sent to the list on Friday.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>NEON support for Big Endian hasn’t been committed to AArch64. There’s a whole kettle of fish there, that probably have about 1-2 weeks of effort left to fix. But this shouldn’t be a merge completion blocker.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l0 level2 lfo1">
<![if !supportLists]><span style="font-family:"Courier New""><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[2d] </b>Support for no fpu/no neon/ no crc<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Support has been ported, but some regression tests from AArch64 haven’t been ported over to ARM64 yet. There is at least one ISel crash that I can see, so there’s still at least some effort left here.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l0 level2 lfo1">
<![if !supportLists]><span style="font-family:"Courier New""><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[DONE] </b>A53 scheduler<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>The A53 scheduler has been ported across and ARM64 now has as much of a schedule as AArch64 does.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l0 level2 lfo1">
<![if !supportLists]><span style="font-family:"Courier New""><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[DONE-ish] </b>Inline assembly<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>All work done – One patch has seen contention from Eric and Jim so may have to be reverted. No big deal if it is though.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l0 level2 lfo1">
<![if !supportLists]><span style="font-family:"Courier New""><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[DONE] </b>Predefines<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>All predefines and driver flags should be correct.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l0 level2 lfo1">
<![if !supportLists]><span style="font-family:"Courier New""><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[?] </b>Conditionalise cyclone/Darwin<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Not done yet, but noone’s raised any issues about it so perhaps there isn’t much to do!<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l0 level2 lfo1">
<![if !supportLists]><span style="font-family:"Courier New""><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[?] </b>ADRP CSE<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>This optimization, being worked on by Jiangning, has been half ported to ARM64. But it hasn’t been committed to AArch64 yet, so it can’t be considered a merge blocker.<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l0 level2 lfo1">
<![if !supportLists]><span style="font-family:"Courier New""><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[2d]</b> fastcc & guaranteed tail opt<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l0 level2 lfo1">
<![if !supportLists]><span style="font-family:"Courier New""><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><b>[1d?] </b>Post-increment NEON ld/st<o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:108.0pt;text-indent:-18.0pt;mso-list:l0 level3 lfo1">
<![if !supportLists]><span style="font-family:Wingdings"><span style="mso-list:Ignore">§<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Kevin is now working on this<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Cheers,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">James<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
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