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skan (Kan Shengchen)
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User Since
Apr 23 2019, 8:52 PM (230 w, 6 d)

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Fri, Sep 15

skan updated subscribers of D156491: [RA] Split a virtual register in cold blocks if it is not assigned preferred physical register.
Fri, Sep 15, 11:56 PM · Restricted Project, Restricted Project

Wed, Sep 13

Herald added a project to D105466: [RuntimeDyld] Implemented relocation of TLS symbols in ELF: Restricted Project.
Wed, Sep 13, 10:22 PM · Restricted Project, Restricted Project

Wed, Sep 6

skan accepted D159250: [X86][RFC] Add new option `-m[no-]evex512` to disable ZMM and 64-bit mask instructions for AVX512 features.

LGTM

Wed, Sep 6, 7:07 PM · Restricted Project, Restricted Project, Restricted Project
skan added inline comments to D159250: [X86][RFC] Add new option `-m[no-]evex512` to disable ZMM and 64-bit mask instructions for AVX512 features.
Wed, Sep 6, 7:07 PM · Restricted Project, Restricted Project, Restricted Project

Sun, Sep 3

skan added inline comments to D159250: [X86][RFC] Add new option `-m[no-]evex512` to disable ZMM and 64-bit mask instructions for AVX512 features.
Sun, Sep 3, 10:53 PM · Restricted Project, Restricted Project, Restricted Project
skan added inline comments to D159250: [X86][RFC] Add new option `-m[no-]evex512` to disable ZMM and 64-bit mask instructions for AVX512 features.
Sun, Sep 3, 10:48 PM · Restricted Project, Restricted Project, Restricted Project

Sun, Aug 27

skan accepted D158950: [X86][BF16] Lower FP_EXTEND for vector types under AVX512BF16.

LGTM

Sun, Aug 27, 7:03 PM · Restricted Project, Restricted Project

Aug 18 2023

skan accepted D158252: Fix regression of D157680.

LGTM

Aug 18 2023, 12:02 AM · Restricted Project, Restricted Project, Restricted Project

Aug 16 2023

skan accepted D158137: Rename warn_drv_overriding_flag_option (-Woverriding-t-option) to warn_drv_overriding_flag_option (-Woverriding-option).

LGTM

Aug 16 2023, 10:46 PM · Restricted Project, Restricted Project
skan accepted D157485: [X86][RFC] Support new feature AVX10.

LGTM

Aug 16 2023, 6:17 PM · Restricted Project, Restricted Project, Restricted Project

Aug 15 2023

skan added inline comments to D157485: [X86][RFC] Support new feature AVX10.
Aug 15 2023, 11:54 PM · Restricted Project, Restricted Project, Restricted Project
skan added inline comments to D157485: [X86][RFC] Support new feature AVX10.
Aug 15 2023, 11:33 PM · Restricted Project, Restricted Project, Restricted Project
skan retitled D157948: [NFC] Fix possibly deref nullptr from Fix possibly deref nullptr to [NFC] Fix possibly deref nullptr.
Aug 15 2023, 9:26 PM · Restricted Project, Restricted Project
skan accepted D157948: [NFC] Fix possibly deref nullptr.

LGTM

Aug 15 2023, 9:25 PM · Restricted Project, Restricted Project
skan added inline comments to D157948: [NFC] Fix possibly deref nullptr.
Aug 15 2023, 8:39 PM · Restricted Project, Restricted Project
skan added inline comments to D157948: [NFC] Fix possibly deref nullptr.
Aug 15 2023, 7:41 AM · Restricted Project, Restricted Project
skan added a comment to D157948: [NFC] Fix possibly deref nullptr.
In D157948#4588131, @XinWang10 wrote:
In D157948#4587733, @skan wrote:
In D157948#4587327, @XinWang10 wrote:
In D157948#4587289, @skan wrote:

Is this a NFC change or a bug fix? If NFC, shouldn't we use assert?

cast could use assert internally, I think it's same to explicit assert.

Then how about others?

OK, the other two places are in same function, line 432 shows

MMI = MMIWP ? &MMIWP->getMMI() : nullptr;

So MMI could be nullptr, I just add add condition for those could deref this MMI, no func change.

Aug 15 2023, 7:40 AM · Restricted Project, Restricted Project
skan added a comment to D157948: [NFC] Fix possibly deref nullptr.
In D157948#4587327, @XinWang10 wrote:
In D157948#4587289, @skan wrote:

Is this a NFC change or a bug fix? If NFC, shouldn't we use assert?

cast could use assert internally, I think it's same to explicit assert.

Aug 15 2023, 3:08 AM · Restricted Project, Restricted Project

Aug 14 2023

skan added a comment to D157948: [NFC] Fix possibly deref nullptr.

Is this a NFC change or a bug fix? If NFC, shouldn't we use assert?

Aug 14 2023, 9:31 PM · Restricted Project, Restricted Project
skan added a reverting change for rG3ce43f16af86: [X86][NFC] Remove dead code in TD for ADCX/ADOX: rGf450fc3edbc9: Revert "[X86][NFC] Remove dead code in TD for ADCX/ADOX".
Aug 14 2023, 1:34 AM · Restricted Project, Restricted Project
skan committed rGf450fc3edbc9: Revert "[X86][NFC] Remove dead code in TD for ADCX/ADOX" (authored by skan).
Revert "[X86][NFC] Remove dead code in TD for ADCX/ADOX"
Aug 14 2023, 1:34 AM · Restricted Project, Restricted Project
skan committed rG3ce43f16af86: [X86][NFC] Remove dead code in TD for ADCX/ADOX (authored by skan).
[X86][NFC] Remove dead code in TD for ADCX/ADOX
Aug 14 2023, 1:21 AM · Restricted Project, Restricted Project
skan committed rGc23b1a0cb7b3: [X86][test] Add missing encoding tests for ADCX/ADOX (authored by skan).
[X86][test] Add missing encoding tests for ADCX/ADOX
Aug 14 2023, 12:43 AM · Restricted Project, Restricted Project
skan closed D157835: [X86][test] Add missing encoding tests for ADCX/ADOX.
Aug 14 2023, 12:43 AM · Restricted Project, Restricted Project
skan added a reviewer for D157835: [X86][test] Add missing encoding tests for ADCX/ADOX: XinWang10.
Aug 14 2023, 12:38 AM · Restricted Project, Restricted Project

Aug 13 2023

skan added reviewers for D157835: [X86][test] Add missing encoding tests for ADCX/ADOX: pengfei, craig.topper, RKSimon.
Aug 13 2023, 11:59 PM · Restricted Project, Restricted Project
skan requested review of D157835: [X86][test] Add missing encoding tests for ADCX/ADOX.
Aug 13 2023, 11:58 PM · Restricted Project, Restricted Project
skan committed rGfda9a9c61ebf: [X86][Codegen] Remove dead code for ADCX/ADOX (authored by skan).
[X86][Codegen] Remove dead code for ADCX/ADOX
Aug 13 2023, 7:24 PM · Restricted Project, Restricted Project
skan closed D157717: [X86][Codegen] Remove dead code for ADCX/ADOX.
Aug 13 2023, 7:23 PM · Restricted Project, Restricted Project
skan updated the summary of D157717: [X86][Codegen] Remove dead code for ADCX/ADOX.
Aug 13 2023, 7:00 PM · Restricted Project, Restricted Project
skan added inline comments to D157717: [X86][Codegen] Remove dead code for ADCX/ADOX.
Aug 13 2023, 7:00 PM · Restricted Project, Restricted Project
skan updated the diff for D157717: [X86][Codegen] Remove dead code for ADCX/ADOX.

Address review comments: keep the predicate

Aug 13 2023, 6:59 PM · Restricted Project, Restricted Project

Aug 12 2023

skan added inline comments to D157717: [X86][Codegen] Remove dead code for ADCX/ADOX.
Aug 12 2023, 6:11 AM · Restricted Project, Restricted Project

Aug 11 2023

skan added inline comments to D157680: [X86]Support options -mno-gather -mno-scatter.
Aug 11 2023, 7:47 AM · Restricted Project, Restricted Project, Restricted Project
skan added reviewers for D157717: [X86][Codegen] Remove dead code for ADCX/ADOX: pengfei, craig.topper, XinWang10.
Aug 11 2023, 7:32 AM · Restricted Project, Restricted Project
skan requested review of D157717: [X86][Codegen] Remove dead code for ADCX/ADOX.
Aug 11 2023, 7:30 AM · Restricted Project, Restricted Project

Aug 7 2023

skan accepted D157260: [X86][NFC]Remove dead code in IfConversion.cpp.

LGTM

Aug 7 2023, 6:39 PM · Restricted Project, Restricted Project

Aug 2 2023

skan accepted D156962: [Driver] Mark m_x86_Features_Group options as TargetSpecific.

LGTM

Aug 2 2023, 8:24 PM · Restricted Project, Restricted Project

Jul 27 2023

skan accepted D155662: [X86] Promote VAES, SHA512, SM4 implied feature to AVX2.
Jul 27 2023, 2:24 AM · Restricted Project, Restricted Project

Jul 26 2023

skan accepted D156285: [X86] Update Model value for Raptor Lake..
Jul 26 2023, 12:31 AM · Restricted Project, Restricted Project, Restricted Project

Jul 24 2023

skan accepted D155798: [X86] Support -march=graniterapids-d and update -march=graniterapids.

LGTM

Jul 24 2023, 6:11 PM · Restricted Project, Restricted Project, Restricted Project, Restricted Project

Jul 20 2023

skan added a comment to D155784: [X86] Update features for sierraforest, grandridge.

LGTM

Jul 20 2023, 6:13 AM · Restricted Project, Restricted Project, Restricted Project

Jul 19 2023

skan accepted D155145: [X86] Add AVX-VNNI-INT16 instructions..
Jul 19 2023, 11:19 PM · Restricted Project, Restricted Project, Restricted Project
skan accepted D155662: [X86] Promote VAES, SHA512, SM4 implied feature to AVX2.

LGTM

Jul 19 2023, 1:40 AM · Restricted Project, Restricted Project
skan added a comment to D155662: [X86] Promote VAES, SHA512, SM4 implied feature to AVX2.
In D155662#4512974, @FreddyYe wrote:

As we noticed in SHA512's spec, it mentions AVX in "CPUID Feature Flag" only, but from software view, we can promote it to AVX2 as all machines having SHA512 have AVX2. Just like VAES here.

Jul 19 2023, 1:21 AM · Restricted Project, Restricted Project

Jul 18 2023

skan added inline comments to D155662: [X86] Promote VAES, SHA512, SM4 implied feature to AVX2.
Jul 18 2023, 7:33 PM · Restricted Project, Restricted Project
skan accepted D155148: [X86] Add SM4 instructions..

LGTM

Jul 18 2023, 7:07 PM · Restricted Project, Restricted Project, Restricted Project

Jul 17 2023

skan accepted D155146: [X86] Add SHA512 instructions..

LGTM

Jul 17 2023, 12:38 AM · Restricted Project, Restricted Project, Restricted Project

Jul 16 2023

skan accepted D155142: [X86] Add PBNDKB instruction..

LGTM

Jul 16 2023, 7:04 PM · Restricted Project, Restricted Project

Jul 13 2023

skan added inline comments to D155142: [X86] Add PBNDKB instruction..
Jul 13 2023, 6:24 PM · Restricted Project, Restricted Project
skan added inline comments to D155142: [X86] Add PBNDKB instruction..
Jul 13 2023, 6:15 PM · Restricted Project, Restricted Project
skan added inline comments to D155147: [X86] Add SM3 instructions..
Jul 13 2023, 6:52 AM · Restricted Project, Restricted Project, Restricted Project
skan added inline comments to D155148: [X86] Add SM4 instructions..
Jul 13 2023, 6:47 AM · Restricted Project, Restricted Project, Restricted Project
skan added inline comments to D155142: [X86] Add PBNDKB instruction..
Jul 13 2023, 6:33 AM · Restricted Project, Restricted Project

Jul 6 2023

skan accepted D154493: [X86] Support some Intel CPUs for cpu_specific/dispatch feature.

LGTM

Jul 6 2023, 5:27 PM · Restricted Project, Restricted Project, Restricted Project

Jul 5 2023

skan accepted D154193: [X86]Remove TEST in AND32ri+TEST16rr in peephole-opt.

LGTM

Jul 5 2023, 10:34 PM · Restricted Project, Restricted Project

Jul 4 2023

skan added inline comments to D154193: [X86]Remove TEST in AND32ri+TEST16rr in peephole-opt.
Jul 4 2023, 2:40 AM · Restricted Project, Restricted Project
skan added inline comments to D154193: [X86]Remove TEST in AND32ri+TEST16rr in peephole-opt.
Jul 4 2023, 1:40 AM · Restricted Project, Restricted Project
skan added inline comments to D154193: [X86]Remove TEST in AND32ri+TEST16rr in peephole-opt.
Jul 4 2023, 12:11 AM · Restricted Project, Restricted Project

Jul 3 2023

skan added inline comments to D154193: [X86]Remove TEST in AND32ri+TEST16rr in peephole-opt.
Jul 3 2023, 8:32 PM · Restricted Project, Restricted Project
skan added a comment to D154193: [X86]Remove TEST in AND32ri+TEST16rr in peephole-opt.

I think you update the revision incorrectly...

Jul 3 2023, 7:55 PM · Restricted Project, Restricted Project

Jun 27 2023

skan accepted D153714: [NFC] Add missing cpu tests in predefined-arch-macros.c.

LGTM

Jun 27 2023, 11:08 PM · Restricted Project, Restricted Project
skan accepted D152989: Pre-commit test for D151696..

LGTM

Jun 27 2023, 8:38 PM · Restricted Project, Restricted Project
skan added inline comments to D152989: Pre-commit test for D151696..
Jun 27 2023, 8:02 PM · Restricted Project, Restricted Project
skan added inline comments to D152989: Pre-commit test for D151696..
Jun 27 2023, 7:46 PM · Restricted Project, Restricted Project

Jun 19 2023

skan added a comment to D152231: [CodeGen] Disable default copy ctor and copy assignment operator for class Array.
In D152231#4427275, @barannikov88 wrote:
In D152231#4427054, @pengfei wrote:

I think the intention here is to harden the code to avoid potential risks, e.g., UAF, caused by shallow copy.
I don't see a problem to have a strict rule for this. According to LLVM policy, downstream only usage is not a strong reason for upstream code. And I think it's also good to define an explicit copy constructor if you are intended to do the copy.

How about making them ' = default' instead?

Jun 19 2023, 12:02 AM · Restricted Project, Restricted Project

Jun 18 2023

skan accepted D152785: [COFF] Support -gsplit-dwarf for COFF on Windows.

LGTM for the MC part.

Jun 18 2023, 10:35 PM · Restricted Project, Restricted Project, Restricted Project

Jun 16 2023

Herald added a project to D51650: Implement target_clones multiversioning: Restricted Project.
Jun 16 2023, 6:23 PM · Restricted Project, Restricted Project

Jun 15 2023

skan added inline comments to D152785: [COFF] Support -gsplit-dwarf for COFF on Windows.
Jun 15 2023, 3:01 AM · Restricted Project, Restricted Project, Restricted Project
skan added inline comments to D152785: [COFF] Support -gsplit-dwarf for COFF on Windows.
Jun 15 2023, 2:56 AM · Restricted Project, Restricted Project, Restricted Project

Jun 8 2023

skan accepted D152340: [NFC][COFF] Split WinCOFFObjectWriter to WinCOFFWriter.

LGTM

Jun 8 2023, 6:15 PM · Restricted Project, Restricted Project

Jun 7 2023

skan accepted D151863: [x86][MC] Fix movdir64b addressing.

LGTM

Jun 7 2023, 11:59 PM · Restricted Project, Restricted Project, Restricted Project

Jun 6 2023

skan accepted D152229: [NFC][COFF] Refine access specifiers for WinCOFFObjectWriter.

LGTM

Jun 6 2023, 3:27 AM · Restricted Project, Restricted Project
skan added a comment to D152229: [NFC][COFF] Refine access specifiers for WinCOFFObjectWriter.

What's the motivation of reordering MCObjectWriter methods?

Jun 6 2023, 3:09 AM · Restricted Project, Restricted Project

Jun 5 2023

skan added a comment to D152229: [NFC][COFF] Refine access specifiers for WinCOFFObjectWriter.

Add a summary about what's refined?

Jun 5 2023, 11:16 PM · Restricted Project, Restricted Project

Jun 4 2023

skan added inline comments to D151863: [x86][MC] Fix movdir64b addressing.
Jun 4 2023, 11:14 PM · Restricted Project, Restricted Project, Restricted Project
skan added inline comments to D151863: [x86][MC] Fix movdir64b addressing.
Jun 4 2023, 11:10 PM · Restricted Project, Restricted Project, Restricted Project
skan added inline comments to D151863: [x86][MC] Fix movdir64b addressing.
Jun 4 2023, 10:45 PM · Restricted Project, Restricted Project, Restricted Project
skan added a comment to D151863: [x86][MC] Fix movdir64b addressing.

Replace the url of the picture in the summary with the plain text?

Jun 4 2023, 10:38 PM · Restricted Project, Restricted Project, Restricted Project
skan accepted D152119: [NFC][COFF] clang-format WinCOFFObjectWriter and MCWinCOFFObjectWriter.

LGTM

Jun 4 2023, 9:42 PM · Restricted Project, Restricted Project

Jun 2 2023

skan accepted D151793: [NFC][COFF] Use COFFSection.MCSection when writeSection.

LGTM with minor suggestion

Jun 2 2023, 4:10 AM · Restricted Project, Restricted Project
skan added a comment to D151793: [NFC][COFF] Use COFFSection.MCSection when writeSection.

Add a NFC or NFCI in the title?

Jun 2 2023, 3:57 AM · Restricted Project, Restricted Project

Jun 1 2023

skan accepted D151930: [X86][MC] Use MCInstrDesc to access CondCode operand.

LGTM, thanks!

Jun 1 2023, 5:49 PM · Restricted Project, Restricted Project

May 31 2023

skan added a comment to D151863: [x86][MC] Fix movdir64b addressing.
In D151863#4386382, @akshaykhadse wrote:

I am unable to write a .s or .ll test for this issue. The test has to be a end-to-end test, but I don't know how. Basically, __asm movdir64b rax, ZMMWORD PTR [arr] written in a .c file gets incorrectly translated to call void asm sideeffect inteldialect "movdir64b rax, ZMMWORD PTR arr", "~{dirflag},~{fpsr},~{flags}"() #1, !srcloc !6 in the IR. The correct reanslation should be call void asm sideeffect inteldialect "movdir64b rax, ZMMWORD PTR $0", "*m,~{flags},~{dirflag},~{fpsr},~{flags}"(ptr elementtype([1000 x i32]) %arr) #1, !srcloc !6

May 31 2023, 11:58 PM · Restricted Project, Restricted Project, Restricted Project
skan added a comment to D151863: [x86][MC] Fix movdir64b addressing.

Maybe you need to add a test case and explain why we check AH here?

May 31 2023, 9:39 PM · Restricted Project, Restricted Project, Restricted Project

May 30 2023

skan accepted D151695: [MC] Disable default copy ctor and copy assignment operator for CodeViewContext.

LGTM

May 30 2023, 3:13 AM · Restricted Project, Restricted Project

May 29 2023

skan accepted D151652: [ms-inline asm] Add error check for `getAsInteger`.

LGTM

May 29 2023, 6:19 PM · Restricted Project, Restricted Project
skan added a comment to D151652: [ms-inline asm] Add error check for `getAsInteger`.

Add a test?

May 29 2023, 5:07 PM · Restricted Project, Restricted Project

May 28 2023

skan accepted D150024: use ref to avoid copy in range for-loop.

LGTM

May 28 2023, 7:19 PM · Restricted Project, Restricted Project

May 26 2023

skan committed rGa919a3a1e739: [CodeGen][NFC] Declare copy constructor & copy assignment as deleted for… (authored by skan).
[CodeGen][NFC] Declare copy constructor & copy assignment as deleted for…
May 26 2023, 6:36 PM · Restricted Project, Restricted Project
skan closed D151538: [CodeGen][NFC] Declare copy constructor & copy assignment as deleted for ScheduleDAG.
May 26 2023, 6:36 PM · Restricted Project, Restricted Project
skan abandoned D150431: [lit] Add knob --run-prefix to allow developers to run LIT on a simulator when real machine is not available.
May 26 2023, 3:57 AM · Restricted Project, Restricted Project
skan updated the diff for D151538: [CodeGen][NFC] Declare copy constructor & copy assignment as deleted for ScheduleDAG.

Address review comments: Add comments

May 26 2023, 3:51 AM · Restricted Project, Restricted Project
skan accepted D151527: [X86][NFC] Fix a bug after D150436 and update some comments.

LGTM

May 26 2023, 3:26 AM · Restricted Project, Restricted Project
skan added a comment to D150024: use ref to avoid copy in range for-loop.

Could you help illustrate why "they're big obj copys"?

May 26 2023, 3:24 AM · Restricted Project, Restricted Project
skan added reviewers for D151538: [CodeGen][NFC] Declare copy constructor & copy assignment as deleted for ScheduleDAG: craig.topper, RKSimon, pengfei, LuoYuanke.
May 26 2023, 12:36 AM · Restricted Project, Restricted Project
skan requested review of D151538: [CodeGen][NFC] Declare copy constructor & copy assignment as deleted for ScheduleDAG.
May 26 2023, 12:35 AM · Restricted Project, Restricted Project

May 20 2023

skan committed rG287dd0142c08: [X86][MC] Simplify some code in X86AsmBackend.cpp, NFCI (authored by skan).
[X86][MC] Simplify some code in X86AsmBackend.cpp, NFCI
May 20 2023, 10:45 PM · Restricted Project, Restricted Project
skan committed rG3f1e9468f68d: [X86][MC][bolt] Share code between encoding optimization and assembler… (authored by skan).
[X86][MC][bolt] Share code between encoding optimization and assembler…
May 20 2023, 6:32 PM · Restricted Project, Restricted Project
skan closed D151028: [X86][MC][bolt] Share code between encoding optimization and assembler relaxation, NFCI.
May 20 2023, 6:31 PM · Restricted Project, Restricted Project