search for: fulllto

Displaying 20 results from an estimated 44 matches for "fulllto".

2018 Apr 11
0
exploring possibilities for unifying ThinLTO and FullLTO frontend + initial optimization pipeline
...uch benefit while complicating the flow. We could achieve what you're looking for by revisiting the flow a little. I would try to consider if we can: 1) always generate summaries. 2) Use the same compile-phase optimization pipeline for ThinLTO and LTO. 3) Decide at link time if you want to do FullLTO or ThinLTO. We haven't got this route 2 years ago because during the bringup we didn't want to affect FullLTO in any way, but it may make sense now to have `clang -flto=thin` and `clang -flto=full` be identical and change the linker plugins to operate either in full-LTO mode or in ThinLTO...
2018 Apr 11
3
exploring possibilities for unifying ThinLTO and FullLTO frontend + initial optimization pipeline
Hi Mehdi, Awesome! It’s a very clear design. The only question left is which pipeline to choose for unified compile-phase optimization pipeline. - ThinLTO compile-phase pipeline? It might very negatively affect compile-time and the memory footprint for FullLTO link-phase. That was the reason why so many optimization were moved from the link-phase to the parallel compile-phase for FullLTO in the first place. - FullLTO compile-phase pipeline? More optimization passes at compile-phase will obviously increase compile time for ThinLTO, though I suspe...
2018 Apr 11
2
exploring possibilities for unifying ThinLTO and FullLTO frontend + initial optimization pipeline
...esday, April 10, 2018 11:53 PM To: Romanova, Katya <katya.romanova at sony.com> Cc: David Blaikie <dblaikie at gmail.com>; Teresa Johnson <tejohnson at google.com>; llvm-dev <llvm-dev at lists.llvm.org> Subject: Re: [llvm-dev] exploring possibilities for unifying ThinLTO and FullLTO frontend + initial optimization pipeline Le mar. 10 avr. 2018 à 23:18, <katya.romanova at sony.com<mailto:katya.romanova at sony.com>> a écrit : Hi Mehdi, Awesome! It’s a very clear design. The only question left is which pipeline to choose for unified compile-phase optimization pipe...
2018 Apr 10
3
exploring possibilities for unifying ThinLTO and FullLTO frontend + initial optimization pipeline
...t; If the scenario was more like a naive build: Multiple BC files generated on a single (multi-core/threaded) machine (but some Thin, some >> Full) & then fed to the linker, I would wonder if it'd be relatively cheap for the LTO step to support this by computing summaries for >> FullLTO files on the fly (without a separate tool/writing the summary to disk, etc). I think so. My understanding that for FullLTO files, it’s possible to perform name anonymous globals pass and compute summaries on the fly, which should allow to perform ThinLTO at link phase. Katya. From: David Blaikie...
2018 Apr 11
0
exploring possibilities for unifying ThinLTO and FullLTO frontend + initial optimization pipeline
...Hi Mehdi, > > > > Awesome! It’s a very clear design. The only question left is which > pipeline to choose for unified compile-phase optimization pipeline. > > - ThinLTO compile-phase pipeline? It might very negatively affect > compile-time and the memory footprint for FullLTO link-phase. That was the > reason why so many optimization were moved from the link-phase to the > parallel compile-phase for FullLTO in the first place. > Just to clarify: "optimizations" were not "moved from the link-phase to the parallel compile-phase for FullLTO",...
2018 Apr 11
0
exploring possibilities for unifying ThinLTO and FullLTO frontend + initial optimization pipeline
...gt; *To:* Romanova, Katya <katya.romanova at sony.com> > *Cc:* David Blaikie <dblaikie at gmail.com>; Teresa Johnson < > tejohnson at google.com>; llvm-dev <llvm-dev at lists.llvm.org> > *Subject:* Re: [llvm-dev] exploring possibilities for unifying ThinLTO > and FullLTO frontend + initial optimization pipeline > > > > > > Le mar. 10 avr. 2018 à 23:18, <katya.romanova at sony.com> a écrit : > > Hi Mehdi, > > > > Awesome! It’s a very clear design. The only question left is which > pipeline to choose for unified compile-ph...
2018 Apr 09
2
exploring possibilities for unifying ThinLTO and FullLTO frontend + initial optimization pipeline
Hello, I am exploring the possibility of unifying the BC file generation phase for ThinLTO and FullLTO. Our third party library providers prefer to give us only one version of the BC archives, rather than test and ship both Thin and Full LTO BC archives. We want to find a way to allow our users to pick either Thin or Full LTO, while having only one "unified" version of the BC archive. Note...
2018 Apr 11
1
exploring possibilities for unifying ThinLTO and FullLTO frontend + initial optimization pipeline
...va, Katya <katya.romanova at sony.com> >> *Cc:* David Blaikie <dblaikie at gmail.com>; Teresa Johnson < >> tejohnson at google.com>; llvm-dev <llvm-dev at lists.llvm.org> >> *Subject:* Re: [llvm-dev] exploring possibilities for unifying ThinLTO >> and FullLTO frontend + initial optimization pipeline >> >> >> >> >> >> Le mar. 10 avr. 2018 à 23:18, <katya.romanova at sony.com> a écrit : >> >> Hi Mehdi, >> >> >> >> Awesome! It’s a very clear design. The only question left is whic...
2018 Apr 10
0
exploring possibilities for unifying ThinLTO and FullLTO frontend + initial optimization pipeline
...atya, [+Teresa since this is about ThinLTO & she's the owner there] I'm not sure how other folks feel, but terminologically I'm not sure I think of these as different formats (for example you mention the idea of stripping the summaries from ThinLTO BC files to then feed them in as FullLTO files - I would imagine it'd be reasonable to modify/fix/improve the linker integration to have it (perhaps optionally) /ignore/ the summaries, or use the summaries but in a non-siloed way (so that there's not that optimization boundary between ThinLTO and FullLTO)) You're dealing with...
2018 Apr 11
1
exploring possibilities for unifying ThinLTO and FullLTO frontend + initial optimization pipeline
I think for ld64, you can mix thinLTO and fullLTO files and ld64 is going to compile them separately and combine the result. (Mehdi can confirm). I think this is aligned with the fact that whether to use full or thin LTO is decided during clang invocation, not linker invocation. I am not against any of the model, but I think we need to do some res...
2018 Apr 11
2
exploring possibilities for unifying ThinLTO and FullLTO frontend + initial optimization pipeline
...> >> Awesome! It’s a very clear design. The only question left is which >> pipeline to choose for unified compile-phase optimization pipeline. >> >> - ThinLTO compile-phase pipeline? It might very negatively affect >> compile-time and the memory footprint for FullLTO link-phase. That was the >> reason why so many optimization were moved from the link-phase to the >> parallel compile-phase for FullLTO in the first place. >> > > Just to clarify: "optimizations" were not "moved from the link-phase to > the parallel compile...
2018 Apr 11
0
exploring possibilities for unifying ThinLTO and FullLTO frontend + initial optimization pipeline
...dering what is the current status of it? Do you have a rough idea of how much time will it take to implement the new LTO API for someone who is new to the project? What are the main benefits of the new LTO API and why it’s important/beneficial to finish this before starting to work on unifying Thin/FullLTO pipeline? Thank you! Katya. From: Teresa Johnson <tejohnson at google.com> Sent: Wednesday, April 11, 2018 6:55 AM To: Mehdi AMINI <joker.eph at gmail.com> Cc: Romanova, Katya <katya.romanova at sony.com>; David Blaikie <dblaikie at gmail.com>; llvm-dev <llvm-dev at lis...
2017 Dec 15
2
RFC: Synthetic function entry counts
...that a static profile is considered precise enough. > > > I think the existing code that checks 'hasEntryCount()' for 'isProfileAvailable' information will need to be refactored to query 'isRealProfileAvailable'. > > Also, one other question: in the case of FullLTO, how do we ensure that > the synthetic profile data from static heuristics is consistent across > TU's? Do we need to recalculate the synthetic profile data? If we need to > recalculate it, presumably we need to know which profile data is synthetic > or not. E.g. in a scenario where...
2017 Dec 15
2
RFC: Synthetic function entry counts
...>> >> I think the existing code that checks 'hasEntryCount()' for >> 'isProfileAvailable' information will need to be refactored to query >> 'isRealProfileAvailable'. >> >> >>> >>> Also, one other question: in the case of FullLTO, how do we ensure that >>> the synthetic profile data from static heuristics is consistent across >>> TU's? Do we need to recalculate the synthetic profile data? If we need to >>> recalculate it, presumably we need to know which profile data is synthetic >>>...
2016 Mar 23
0
[RFC] Lazy-loading of debug info metadata
On Tue, Mar 22, 2016 at 9:48 PM, Duncan Exon Smith <dexonsmith at apple.com> wrote: > > On Mar 22, 2016, at 8:04 PM, David Blaikie <dblaikie at gmail.com> wrote: > > +pcc, who had some other ideas/patch out for improving memory usage of > debug info > +Reid, who's responsible for the windows/CodeView/PDB debug info which is > motivating some of the ideas about
2017 Dec 15
2
RFC: Synthetic function entry counts
On Fri, Dec 15, 2017 at 12:22 AM, Sean Silva <chisophugis at gmail.com> wrote: > IIUC, this proposal is just saying that we should infer a static profile > for entry counts just like we do for branch probabilities. In the case of > entry counts, we do not hide that information behind an analysis like BPI, > so currently just annotating synthetic PGO entry counts is a simple >
2018 Feb 26
1
Current PGO status
Hello David and all involved =) On 02/05/2018 09:38 AM, Xinliang David Li wrote: > ThinLTO also works well with PGO. Could you please let me know if there are any problems which prevent using PGO with FullLTO? Thanks in advance! -- Best Regards, Victor Leschuk | Software Engineer | Access Softek
2017 Jan 16
3
Your help needed: List of LLVM Open Projects 2017
On Mon, Jan 16, 2017 at 12:31 PM, Sean Silva via llvm-dev <llvm-dev at lists.llvm.org> wrote: > Do we have any open projects on LLD? > > I know we usually try to avoid any big "projects" and mainly add/fix things > in response to user needs, but just wondering if somebody has any ideas. > I'm not particularly active in lld anymore, but the last big item I'd
2018 Aug 06
3
Getting Object Files During LTO
Is there a way to get object files from the LTO step before the linker performs the final link phase? What I'd like to do is given these bitcode files: a.lto.o, b.lto.o, c.lto.o run LTO on them and get out the object files: a.o, b.o, c.o (These .o files hold the code that is sent directly to the final link phase.) If there doesn't currently exist a way, is such a thing possible?
2016 Mar 23
2
[RFC] Lazy-loading of debug info metadata
> On Mar 22, 2016, at 8:04 PM, David Blaikie <dblaikie at gmail.com> wrote: > > +pcc, who had some other ideas/patch out for improving memory usage of debug info > +Reid, who's responsible for the windows/CodeView/PDB debug info which is motivating some of the ideas about changes to type emission > > So how does this relate, or not, to Peter's (pcc) work trying to