twoh (Taewook Oh)
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User Since
Feb 4 2016, 3:03 PM (120 w, 2 d)

Recent Activity

Apr 25 2018

twoh committed rL330844: [ICP] Do not attempt type matching for variable length arguments..
[ICP] Do not attempt type matching for variable length arguments.
Apr 25 2018, 10:22 AM
twoh closed D46026: [ICP] Do not attempt type matching for variable length arguments..
Apr 25 2018, 10:22 AM
twoh updated the diff for D46026: [ICP] Do not attempt type matching for variable length arguments..

Addressing comment from @mssimpso. Thanks!

Apr 25 2018, 12:39 AM

Apr 24 2018

twoh added a comment to D45527: [OpenMP] Fix affinity API for KMP_AFFINITY=none|compact|scatter.

Hello @jlpeyton @tlwilmar, is there a chance that this breaks runtime/test/ompt/misc/api_calls_from_other_thread.cpp test? ompt_get_num_places() is expected to return 0 from the test but with this patch it returns 1, and I think it is because kmp_affinity_num_masks is set to 1 from kmp_create_affinity_none_places().

Apr 24 2018, 11:41 PM · Restricted Project
twoh created D46026: [ICP] Do not attempt type matching for variable length arguments..
Apr 24 2018, 12:16 PM

Apr 4 2018

twoh committed rL329250: [CallSiteSplitting] Do not perform callsite splitting inside landing pad.
[CallSiteSplitting] Do not perform callsite splitting inside landing pad
Apr 4 2018, 9:20 PM
This revision was not accepted when it landed; it landed in state Needs Review.
Apr 4 2018, 9:20 PM
twoh added inline comments to D45130: [CallSiteSplitting] Do not perform callsite splitting inside landing pad.
Apr 4 2018, 9:17 PM
twoh added inline comments to D45130: [CallSiteSplitting] Do not perform callsite splitting inside landing pad.
Apr 4 2018, 12:29 AM
twoh updated the diff for D45130: [CallSiteSplitting] Do not perform callsite splitting inside landing pad.

Addressing comments from @fhahn and @junbuml's comments. Thank you!

Apr 4 2018, 12:25 AM

Apr 3 2018

twoh retitled D45130: [CallSiteSplitting] Do not perform callsite splitting inside landing pad from Do not perform callsite splitting inside landing pad to [CallSiteSplitting] Do not perform callsite splitting inside landing pad.
Apr 3 2018, 8:13 AM

Apr 2 2018

twoh updated the diff for D45130: [CallSiteSplitting] Do not perform callsite splitting inside landing pad.

Thanks @fhahn for the comments! I added comments about why we don't perform splitting for the callsites inside the landing pad. Please let me know if you think it is too verbose.

Apr 2 2018, 10:45 PM
twoh updated the diff for D45130: [CallSiteSplitting] Do not perform callsite splitting inside landing pad.

Addressing @junbuml's comments. Thanks!

Apr 2 2018, 9:59 PM

Mar 31 2018

twoh created D45130: [CallSiteSplitting] Do not perform callsite splitting inside landing pad.
Mar 31 2018, 3:20 PM

Mar 12 2018

twoh committed rL327358: [ThinLTO] Add funtions in callees metadata to CallGraphEdges.
[ThinLTO] Add funtions in callees metadata to CallGraphEdges
Mar 12 2018, 9:29 PM
twoh closed D44399: [ThinLTO] Add funtions in callees metadata to CallGraphEdges.
Mar 12 2018, 9:29 PM
twoh updated the diff for D44399: [ThinLTO] Add funtions in callees metadata to CallGraphEdges.

Update test to check f2.llvm.0 as well.

Mar 12 2018, 4:08 PM
twoh added a comment to D44399: [ThinLTO] Add funtions in callees metadata to CallGraphEdges.

@tejohnson Thanks for the clarification. Regarding hotness, I'm not sure if providing "some" hotness is better than leaving it as unknown if profile data is not provided (If profile data is given, as you said, VP metadata will be attached to the callsite). I'm afraid that synthesized hotness may confuse optimizers, but please let me know if you have different idea.

Mar 12 2018, 4:07 PM
twoh added a comment to D44399: [ThinLTO] Add funtions in callees metadata to CallGraphEdges.

@tejohnson I think your right. What I meant was that when the metadata is imported to bar.o, it references f1 and f2 by their promoted names, which makes the declarations with the promoted names to be added. Did I get it right, or still miss something?

Mar 12 2018, 3:01 PM
twoh created D44399: [ThinLTO] Add funtions in callees metadata to CallGraphEdges.
Mar 12 2018, 12:16 PM

Dec 6 2017

twoh committed rL319904: Stringizing raw string literals containing newline.
Stringizing raw string literals containing newline
Dec 6 2017, 9:01 AM
twoh committed rC319904: Stringizing raw string literals containing newline.
Stringizing raw string literals containing newline
Dec 6 2017, 9:01 AM
twoh closed D39279: Stringizing raw string literals containing newline by committing rC319904: Stringizing raw string literals containing newline.
Dec 6 2017, 9:01 AM

Dec 5 2017

twoh updated the diff for D39279: Stringizing raw string literals containing newline.

clang-format

Dec 5 2017, 10:06 AM
twoh updated the diff for D39279: Stringizing raw string literals containing newline.

@jkorous-apple Got it. I agree that it would be better to move the comments to the header. Will land it soon. Thanks!

Dec 5 2017, 9:48 AM

Dec 4 2017

twoh updated the diff for D39279: Stringizing raw string literals containing newline.

Thanks @jkorous-apple for the comment. I think your suggestion is a more
precise description for the implementation, and adjusted the comments
accordingly.

Dec 4 2017, 10:35 AM

Nov 29 2017

twoh added a comment to D39279: Stringizing raw string literals containing newline.

@jkorous-apple Thanks for the comments! Yeah, I was thinking of O(lenght_of_string) approach, but considering the complicatedness of the implementation (I guess the real implementation would be a bit more complex than your pseudo implementation to handle quote and '\n\r' '\r\n' cases) I decided to stay with O(length_of_string * number_of_endlines_in_string) but optimizing the number of move operations.

Nov 29 2017, 10:29 AM

Nov 27 2017

twoh updated the diff for D39279: Stringizing raw string literals containing newline.

Thanks @jkorous-apple for your comments. I modified the type for the variables and replaced unnecessary inserts and erases with updates.

Nov 27 2017, 10:08 PM

Nov 20 2017

twoh updated the diff for D39279: Stringizing raw string literals containing newline.

Addressing @vsapsai's comments. Thank you for the suggestion! Added test case actually finds an off-by-one error in the original patch. I improved the comments as well.

Nov 20 2017, 2:35 PM

Nov 1 2017

twoh added a comment to D38061: Set AnonymousTagLocations false for ASTContext if column info is expected not to be used.

Ping. Thanks!

Nov 1 2017, 1:29 PM
twoh added a comment to D39279: Stringizing raw string literals containing newline.

Ping. Thanks!

Nov 1 2017, 1:28 PM

Oct 25 2017

twoh updated the diff for D39279: Stringizing raw string literals containing newline.

clang-format

Oct 25 2017, 12:01 AM

Oct 24 2017

twoh created D39279: Stringizing raw string literals containing newline.
Oct 24 2017, 11:58 PM

Sep 29 2017

twoh added a comment to D38199: Make test supported only when armv7s target is available..

Ping. Thanks!

Sep 29 2017, 8:57 AM

Sep 27 2017

twoh added a comment to D38061: Set AnonymousTagLocations false for ASTContext if column info is expected not to be used.

Ping, Thanks!

Sep 27 2017, 11:30 AM

Sep 25 2017

twoh created D38199: Make test supported only when armv7s target is available..
Sep 25 2017, 5:02 AM

Sep 19 2017

twoh updated the summary of D38061: Set AnonymousTagLocations false for ASTContext if column info is expected not to be used.
Sep 19 2017, 6:56 PM
twoh created D38061: Set AnonymousTagLocations false for ASTContext if column info is expected not to be used.
Sep 19 2017, 4:31 PM

Aug 28 2017

twoh committed rL311906: Create PHI node for the return value only when the return value has uses..
Create PHI node for the return value only when the return value has uses.
Aug 28 2017, 11:58 AM
twoh closed D37176: Create PHI node for the return value only when the return value has uses. by committing rL311906: Create PHI node for the return value only when the return value has uses..
Aug 28 2017, 11:58 AM
twoh updated the diff for D37176: Create PHI node for the return value only when the return value has uses..

Addressing @davidxl and @xur's comment. Thanks!

Aug 28 2017, 10:43 AM
twoh updated the diff for D37176: Create PHI node for the return value only when the return value has uses..

Fix a test.

Aug 28 2017, 8:52 AM

Aug 25 2017

twoh updated the summary of D37176: Create PHI node for the return value only when the return value has uses..
Aug 25 2017, 10:10 PM
twoh created D37176: Create PHI node for the return value only when the return value has uses..
Aug 25 2017, 9:12 PM

Aug 16 2017

twoh committed rL311037: Use the file name from linemarker for debug info if an input is preprocessed….
Use the file name from linemarker for debug info if an input is preprocessed…
Aug 16 2017, 12:37 PM
twoh closed D36474: Use the file name from linemarker for debug info if an input is preprocessed source. by committing rL311037: Use the file name from linemarker for debug info if an input is preprocessed….
Aug 16 2017, 12:37 PM
twoh added a comment to D34796: upporting -f(no)-reorder-functions flag, clang side change.

Friendly ping. @davidxl, I think there's no harm to make clang consistent with gcc for compiler options, and I wonder if you have any concerns that I may miss. Thanks!

Aug 16 2017, 10:42 AM
twoh added a comment to D36474: Use the file name from linemarker for debug info if an input is preprocessed source..

Ping. Thanks!

Aug 16 2017, 10:38 AM

Aug 10 2017

twoh committed rL310642: Make .file directive to have basename only.
Make .file directive to have basename only
Aug 10 2017, 11:18 AM
twoh closed D36018: Make .file directive to have basename only by committing rL310642: Make .file directive to have basename only.
Aug 10 2017, 11:18 AM

Aug 8 2017

twoh updated the diff for D36474: Use the file name from linemarker for debug info if an input is preprocessed source..

Addressing dblaikie's comments. Thanks!

Aug 8 2017, 11:10 AM
twoh updated the diff for D36474: Use the file name from linemarker for debug info if an input is preprocessed source..

Relocate.

Aug 8 2017, 10:39 AM
twoh created D36474: Use the file name from linemarker for debug info if an input is preprocessed source..
Aug 8 2017, 10:37 AM

Aug 7 2017

twoh added a comment to D36018: Make .file directive to have basename only.

Ping. Thanks!

Aug 7 2017, 9:35 AM

Aug 5 2017

twoh added a comment to D34796: upporting -f(no)-reorder-functions flag, clang side change.

I think it is generally good to match what GCC does to not to confuse people.

Aug 5 2017, 11:47 AM

Aug 3 2017

twoh committed rL309985: Move unit test to the proper location.
Move unit test to the proper location
Aug 3 2017, 2:08 PM
twoh closed D36282: Move unit test to the proper location by committing rL309985: Move unit test to the proper location.
Aug 3 2017, 2:08 PM
twoh created D36282: Move unit test to the proper location.
Aug 3 2017, 1:13 PM

Jul 31 2017

twoh updated the diff for D34796: upporting -f(no)-reorder-functions flag, clang side change.

Update documentation. Please let me know if I need to update other documents as well. Thanks!

Jul 31 2017, 12:01 PM
twoh added a comment to D34795: Supporting -f(no)-reorder-functions flag, llvm side change.

@davidxl I think it is theoretically possible, if the if branch is not taken on line 294. Did I miss something? Thanks!

Jul 31 2017, 9:55 AM
twoh added a comment to D34795: Supporting -f(no)-reorder-functions flag, llvm side change.

Ping. Thanks!

Jul 31 2017, 8:51 AM
twoh added a comment to D34796: upporting -f(no)-reorder-functions flag, clang side change.

Ping. Thanks!

Jul 31 2017, 8:51 AM

Jul 28 2017

twoh updated the diff for D36018: Make .file directive to have basename only.

Delete unnecessary line from the test.

Jul 28 2017, 2:11 PM
twoh created D36018: Make .file directive to have basename only.
Jul 28 2017, 2:03 PM

Jun 29 2017

twoh committed rL306758: Remove redundant copy in recurrences.
Remove redundant copy in recurrences
Jun 29 2017, 4:11 PM
twoh closed D31821: Remove redundant copy in recurrences by committing rL306758: Remove redundant copy in recurrences.
Jun 29 2017, 4:11 PM
twoh updated the diff for D31821: Remove redundant copy in recurrences.

@wmi Good call! I fixed the code per your suggestion. Thanks!

Jun 29 2017, 1:31 PM
twoh updated the diff for D31821: Remove redundant copy in recurrences.

minor fix.

Jun 29 2017, 11:04 AM
twoh updated the diff for D31821: Remove redundant copy in recurrences.

Addressing comments from @wmi. Thank you for the suggestion!

Jun 29 2017, 11:03 AM

Jun 28 2017

twoh added a comment to D34795: Supporting -f(no)-reorder-functions flag, llvm side change.

https://reviews.llvm.org/D34796 is clang side change.

Jun 28 2017, 6:12 PM
twoh created D34796: upporting -f(no)-reorder-functions flag, clang side change.
Jun 28 2017, 6:10 PM
twoh created D34795: Supporting -f(no)-reorder-functions flag, llvm side change.
Jun 28 2017, 6:05 PM
twoh added a comment to D31821: Remove redundant copy in recurrences.

Ping. Thanks!

Jun 28 2017, 11:15 AM

Jun 25 2017

twoh added a comment to D34373: [LV] Optimize for size when vectorizing loops with tiny trip count.

Hello @Ayal, can you please update the comments per @hfinkel's request so that I can accept the patch? Thanks!

Jun 25 2017, 2:58 PM

Jun 20 2017

twoh updated the diff for D31821: Remove redundant copy in recurrences.

Addressing @wmi's concern by limiting the targets to the recurrence cycles that only the last instruction of the recurrence (that feeds the PHI instruction) can have uses outside of the recurrence. This is not an ideal solution yet, and more fundamental solution (such as having recurrence optimization as a separate pass and/or using live range analysis for it) should follow. But still I think it is worth to have it here.

Jun 20 2017, 1:44 PM
twoh added a comment to D34373: [LV] Optimize for size when vectorizing loops with tiny trip count.
In D34373#785485, @twoh wrote:
In D34373#784975, @twoh wrote:

I think this is a right approach, but concerned that the experimental results I shared on D32451 show that it is generally better to not to vectorize the low trip count loops. @Ayal, I wonder if you have any results that this patch actually improves the performance. Thanks!

I know that we're currently missing opportunities for large vectorizable loops with low (static) trip counts. Smaller inner loops are also good candidates for unpredicated vectorization, but we may need to be a bit careful because of modeling inaccuracies and phase-ordering effects (e.g. if we don't vectorize a loop, then we'll end up unrolling it when the unroller runs).

Got it. My concern was for small single-level loops with low trip counts, as I observe them pretty frequently. I have no objection accepting this patch and improve the cost estimator separately.

Do you mean that you see such loops frequently with dynamically-small trip counts, or with static trip counts? I assume the small loops with (small) static trip counts will generally be unrolled.

Jun 20 2017, 11:11 AM
twoh added a comment to D34373: [LV] Optimize for size when vectorizing loops with tiny trip count.
In D34373#784975, @twoh wrote:

I think this is a right approach, but concerned that the experimental results I shared on D32451 show that it is generally better to not to vectorize the low trip count loops. @Ayal, I wonder if you have any results that this patch actually improves the performance. Thanks!

I know that we're currently missing opportunities for large vectorizable loops with low (static) trip counts. Smaller inner loops are also good candidates for unpredicated vectorization, but we may need to be a bit careful because of modeling inaccuracies and phase-ordering effects (e.g. if we don't vectorize a loop, then we'll end up unrolling it when the unroller runs).

Jun 20 2017, 9:17 AM

Jun 19 2017

twoh added a comment to D34373: [LV] Optimize for size when vectorizing loops with tiny trip count.

I think this is a right approach, but concerned that the experimental results I shared on D32451 show that it is generally better to not to vectorize the low trip count loops. @Ayal, I wonder if you have any results that this patch actually improves the performance. Thanks!

Jun 19 2017, 10:13 PM
twoh committed rL305729: Improve profile-guided heuristics to use estimated trip count..
Improve profile-guided heuristics to use estimated trip count.
Jun 19 2017, 11:50 AM
twoh closed D32451: Improve profile-guided heuristics to use estimated trip count. by committing rL305729: Improve profile-guided heuristics to use estimated trip count..
Jun 19 2017, 11:49 AM
twoh updated the diff for D32451: Improve profile-guided heuristics to use estimated trip count..

Addressing comments from @tejohnson. Thanks!

Jun 19 2017, 11:35 AM

Jun 18 2017

twoh added a comment to D32451: Improve profile-guided heuristics to use estimated trip count..

@tejohnson Sorry for the late reply. I was out of internet for days. I have no objection to set the default value to true, but prefer to have it as a separate patch so that we can track the impact on performance of each chance more easily.

Jun 18 2017, 5:20 PM

Jun 12 2017

twoh added a comment to D32451: Improve profile-guided heuristics to use estimated trip count..

Ping. Thanks!

Jun 12 2017, 1:42 PM

Jun 10 2017

twoh added a comment to D31821: Remove redundant copy in recurrences.

@wmi Not at all! Thanks for your comments.

Jun 10 2017, 9:46 PM

Jun 7 2017

twoh added a comment to D31821: Remove redundant copy in recurrences.

ping. thanks!

Jun 7 2017, 2:29 PM

Jun 4 2017

twoh added inline comments to D32451: Improve profile-guided heuristics to use estimated trip count..
Jun 4 2017, 10:10 PM

Jun 2 2017

twoh added inline comments to D32451: Improve profile-guided heuristics to use estimated trip count..
Jun 2 2017, 12:54 PM

May 31 2017

twoh added a comment to D31821: Remove redundant copy in recurrences.

FYI, below is the compile difference in percentage for spec2006:

May 31 2017, 11:11 AM
twoh updated the diff for D31821: Remove redundant copy in recurrences.

Add missing reference.

May 31 2017, 11:09 AM
twoh updated the diff for D31821: Remove redundant copy in recurrences.

Reimplement the feature in peephole optimizer. This patch makes the values in the recurrence cycle to be tied to each other if possible.

May 31 2017, 10:28 AM
twoh added a comment to D32451: Improve profile-guided heuristics to use estimated trip count..

Ping. Thanks!

May 31 2017, 9:50 AM

May 22 2017

twoh added a comment to D32451: Improve profile-guided heuristics to use estimated trip count..

Comparing the existing implementation and this patch, I don't observe noticeable compile time different with Video-SIMDBench. I compiled the benchmark suite 3 times each and the median was 27.12 sec vs 27.55 sec, while the average was 27.96sec vs 27.89 sec. There were some code size differences, but it is simply more vectorization results bigger code size. There's no difference between OptForSize and non-vectorized.

May 22 2017, 3:33 PM

May 19 2017

twoh updated the diff for D32451: Improve profile-guided heuristics to use estimated trip count..

Addressing Ayal's comments.

May 19 2017, 1:20 PM
twoh added a comment to D31821: Remove redundant copy in recurrences.

@wmi Thank you for your reply. I agree on you that we should consider tied operand group, and as @qcolombet mentioned in the previous comment, if tie operand information is already available before this pass, I'd like to discuss where would be the best place to implement this.

May 19 2017, 1:14 PM

May 17 2017

twoh added a comment to D31821: Remove redundant copy in recurrences.

@qcolombet Actually you're right. Having tied operands, this can be done within SSA. Do you have a suggestion for a better place to implement this? I thought what isRevCopyChain does is most close to what this patch does.

May 17 2017, 1:25 PM

May 16 2017

twoh added a comment to D31821: Remove redundant copy in recurrences.

@MatzeB Thank you for your comments. I'm collection compile time numbers now with spec2006. For our internal benchmark, which takes about ~40min to compile, the compile time difference was negligible.

May 16 2017, 2:42 PM
twoh updated the diff for D31821: Remove redundant copy in recurrences.

Addressing comments from @MatzeB.

May 16 2017, 2:42 PM

May 13 2017

twoh added a comment to D32451: Improve profile-guided heuristics to use estimated trip count..

@Ayal Thanks for the pointer.

May 13 2017, 10:38 PM

May 12 2017

twoh added a comment to D31821: Remove redundant copy in recurrences.

Ping. Can someone please let me know what would be the best way to have this patch reviewed? Thanks!

May 12 2017, 2:36 PM

May 11 2017

twoh added a comment to D32451: Improve profile-guided heuristics to use estimated trip count..

I don't have a strong opinion about treating static trip count and profile-based trip count or not. I treated them separately because existing implementation sets OptForSize to true instead of returning false when it makes a profile-based decision. It would be great if someone can explain the reason behind that.

May 11 2017, 10:05 PM