similar to: Getting Object Files During LTO

On Mon, Aug 6, 2018 at 4:30 PM Quentin Colombet <quentin.colombet at gmail.com> wrote: > Hi Bill, > > > 2018-08-06 16:13 GMT-07:00 Bill Wendling via llvm-dev < > llvm-dev at lists.llvm.org>: > > 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 > >

On Tue, Apr 10, 2018 at 11:52 PM, Mehdi AMINI <joker.eph at gmail.com> wrote: > > > 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-phase 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.

Hi Teresa, Thank you so much for your reply! I am on vacation until the end of this week and on EuroLLVM next week, so I have to apologize in advance that my replies are delayed. >>Right - see my reply on this from last night, at the very least the ThinLTO importing thresholds will need retuning if we will >>perform optimizations like unrolling/vectorization/etc that tend to

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 research before making the effort to switch the model.

Hi, It is non trivial to recompute summaries (which is why we have summaries in the bitcode in the first place by the way), because bitcode is expensive to load. I think shipping two different variant of the bitcode, one with and one without summaries isn't providing much benefit while complicating the flow. We could achieve what you're looking for by revisiting the flow a little. I

Hi Katya, [+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

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-phase optimization pipeline. > > - ThinLTO compile-phase pipeline? It might very negatively affect > compile-time and the memory footprint for FullLTO link-phase.

Hi David, Thank you so much for your reply! >> You're dealing with a situation where you are shipped BC files offline and then do one, or multiple builds with these BC files? Yes, that’s exactly the case. >> 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

From: Mehdi AMINI <joker.eph at gmail.com> Sent: Tuesday, 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

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

Le mer. 11 avr. 2018 à 11:20, <katya.romanova at sony.com> a écrit : > > > > > *From:* Mehdi AMINI <joker.eph at gmail.com> > *Sent:* Tuesday, 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

See attached some quick slides (backup from the dev meeting talk) about the pass pipeline. -- Mehdi Le mer. 11 avr. 2018 à 12:18, Mehdi AMINI <joker.eph at gmail.com> a écrit : > > > Le mer. 11 avr. 2018 à 11:20, <katya.romanova at sony.com> a écrit : > >> >> >> >> >> *From:* Mehdi AMINI <joker.eph at gmail.com> >> *Sent:*

I’ve put up a patch here: https://reviews.llvm.org/D79769 <https://reviews.llvm.org/D79769> that adds a unified pipeline that targets can opt-into. It has some similarities with forcing fallbacks, but uses a different mechanism to do so to preserve the abort behavior. It therefore requires that every GISel pass needs to explicitly check whether the GISel selector is being requested rather

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

On Mon, May 1, 2017 at 11:06 AM, Mehdi AMINI <joker.eph at gmail.com> wrote: > > > 2017-04-25 12:11 GMT-07:00 Peter Collingbourne <peter at pcc.me.uk>: > >> Hi all, >> >> I've been making a number of changes to the summary representation >> recently, and I wanted to lay out some of my plans so that folks are aware >> of my ultimate

Hi all. I’m trying to get GlobalISel to work better with LTO. At the moment if you enable it via -fglobal-isel, it only adds the -mllvm -global-isel and related options to the cc1 invocation. With LTO, that doesn’t work as we need to encode codegen options into the bitcode, usually via function attributes. Does anyone have any ideas on how to achieve this? The only way I can see it working is if

2018-02-13 17:46 GMT-08:00 Mehdi AMINI <joker.eph at gmail.com>: > > > 2018-02-13 13:29 GMT-08:00 Quentin Colombet <qcolombet at apple.com>: > >> Hi Mehdi, >> >> >> On Feb 13, 2018, at 12:34 PM, Mehdi AMINI <joker.eph at gmail.com> wrote: >> >> >> >> 2018-02-08 17:34 GMT-08:00 Quentin Colombet via llvm-dev < >>

> On May 15, 2016, at 12:43 AM, vivek pandya <vivekvpandya at gmail.com> wrote: > > > > Vivek Pandya > > > On Wed, May 11, 2016 at 9:43 AM, Mehdi Amini <mehdi.amini at apple.com <mailto:mehdi.amini at apple.com>> wrote: > >> On May 10, 2016, at 6:06 PM, Hal Finkel <hfinkel at anl.gov <mailto:hfinkel at anl.gov>> wrote: >>

On Thu, Feb 26, 2015 at 4:09 AM, Renato Golin <renato.golin at linaro.org> wrote: > On 26 February 2015 at 00:57, Ahmed Bougacha <ahmed.bougacha at gmail.com> wrote: >> -- A way forward >> One obvious way to improve it is: look at uses of globals, and try to >> form sets of globals commonly used together. The tricky part is to >> define heuristics for