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</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Hi all,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>It’s been two weeks since I sent the last merge progress email, so here is an update.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b>TL;DR: Almost done!</b><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Tim is considering suggesting making the final switchover sometime next week. This would be the final push, where AArch64 gets deleted and ARM64 gets renamed to AArch64, and would signal the end of the merge process. If any of you know of any reason why these two loving backends cannot be merged, speak now or forever hold your peace! <span style='font-family:Wingdings'>J</span><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>[1w]</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 Clang regression tests ported.<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]>Almost all LLVM regression tests ported – the only thing left is MC-level diagnostics tests. These are in progress (Bradley) – currently 25% of the way through the diagnostics test file.<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]>No further information available, but no public bugs raised.<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> 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 test suites pass.<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>[DONE]</b> MC Hammer<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>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]>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, which we have now hit.<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>[DONE]</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]>Big endian support is now complete and all known bugs are fixed upstream. This includes NEON instruction selection.<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]>I’m still running testing to validate, but this can be thought of as complete.<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>Support for no fpu/no neon/ no crc<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: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>Inline assembly<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: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>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]>Only the “LDR q” -> “LDP d, d” splitting pass to really conditionalise – only benchmarks will really show 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>[?] </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: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]>Jiangning and Quentin are working together on testing and benchmarking this patch.<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: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]>Fastcc support (proper tail call optimization) is in progress (Jiangning)<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>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]>Post-indexed NEON loads and stores are in progress (Hao)<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></body></html>