search for: thinlto

Thanks! Question about the final link step: Do I provide all the object files to the link step, i.e. something like: clang++ -o thinlto main-native.o lib/lib-native.o src/lib-native.o Do I need to provide --start-lib markers on that final link step as well? Tanoy On Tue, Jun 18, 2019 at 10:37 AM Teresa Johnson <tejohnson at google.com> wrote: > Hi Tanoy, > > You can't use distributed ThinLTO with archives (th...

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?...

...gt; 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 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 optim...

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. 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: &quot...

.... 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. 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. >> > &g...

..., 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> a écrit : > > Hi Mehdi, > > > > Awesome! It’s a very clear design. The only question left is which > pipeline to choose for u...

As discussed in the high-level ThinLTO RFC ( http://lists.cs.uiuc.edu/pipermail/llvmdev/2015-May/086211.html), we would like to add support for native object wrapped bitcode and ThinLTO information. Based on comments on the mailing list, I am adding support for ThinLTO in both normal bitcode files, as well as native-object wrapped bitc...

...>> *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...

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 increase code side. Have you only used internal benchmarks for tuning the ThinLTO’s importing thresholds? A couple of old postings mentioned public benchmarks for perf me...

..., 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 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...

I am trying to work through the usage of thinlto for distributed builds. Here is the simple thinlto usage, just add -flto=thin everywhere, easy: clang++ -flto=thin -O3 -c -o CreateWay_.o -DSPEC_CPU -DNDEBUG -DSPEC_CPU_LITTLE_ENDIAN -Wno-dangling-else CreateWay_.cpp clang++ -flto=thin -O3 -c -o Places_.o -DSPEC_CPU...

I'm trying to run distributed ThinLTO without thin archives. When I do, I get an error in the optimizer when clang tries to open a nonexistent file: clang++ -flto=thin -Xclang -fno-lto-unit -O3 -c main.cpp -o main.o clang++ -flto=thin -Xclang -fno-lto-unit -O3 -c lib/lib.cpp -o lib/lib.o clang++ -flto=thin -Xclang -fno-lto-unit -O3 -c...

...rt 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 <dblaikie at gmail.com> Sent: Tuesday, April 10, 2018 7:38 AM To: Romanova, Katya <katya.romanova at sony.com>; Teresa Johnson <tejohnson at google.com> Cc: llvm-dev at lists.llvm.org Subject: Re: [llvm-dev] exploring possibilities for u...

...e with other tools as well, correct? Thanks again --david From: Teresa Johnson <tejohnson at google.com> Date: Tuesday, January 8, 2019 at 4:11 PM To: David Callahan <dcallahan at fb.com> Cc: LLVM Dev Mailing list <llvm-dev at lists.llvm.org> Subject: Re: [llvm-dev] distributed thinlto usage Hi David, That looks basically right, so I am not sure offhand what is wrong. Looks like this is the astar spec binary, so I will try to repro it tomorrow morning. What linker are you using? Note that if your link involves archives of .a files, you will want to ensure that the final native...

...of these tools is lacking? > Sorry I can not parse your questions properly. Can you make it clearer? David > > Alex > > > On May 13, 2015, at 7:44 PM, Teresa Johnson <tejohnson at google.com> > wrote: > > > > I've included below an RFC for implementing ThinLTO in LLVM, looking > > forward to feedback and questions. > > Thanks! > > Teresa > > > > > > > > RFC to discuss plans for implementing ThinLTO upstream. Background can > > be found in slides from EuroLLVM 2015: > > > https://drive.google.com/op...

...work, conceptually the framework should not be too hard to be ported to another target. One thing I was not aware of (perhaps the description did not make it clear) is that Propeller intends to **reorder basic block sections across translation units**. This is something that full LTO can do while ThinLTO cannot. Our internal systems cannot afford doing a full LTO (**Can we fix the bottleneck of full LTO** [1]?) for large executables and I believe some other users are in the same camp. Now, with ThinLTO, the post link optimization scheme will inevitably require help from the linker/compiler. It see...

I've included below an RFC for implementing ThinLTO in LLVM, looking forward to feedback and questions. Thanks! Teresa RFC to discuss plans for implementing ThinLTO upstream. Background can be found in slides from EuroLLVM 2015: https://drive.google.com/open?id=0B036uwnWM6RWWER1ZEl5SUNENjQ&authuser=0) As described in the talk, we have a pr...

...command failed with exit code 1 (use -v to see invocation) From: Teresa Johnson <tejohnson at google.com> Date: Tuesday, January 8, 2019 at 4:57 PM To: David Callahan <dcallahan at fb.com> Cc: LLVM Dev Mailing list <llvm-dev at lists.llvm.org> Subject: Re: [llvm-dev] distributed thinlto usage On Tue, Jan 8, 2019 at 4:36 PM David Callahan <dcallahan at fb.com<mailto:dcallahan at fb.com>> wrote: Thanks Teresa Yes it is astar, happen to send a tar of the sources but they are just copies from the spec distribution The ld command is: GNU ld (GNU Binutils) 2.29.1 Could y...

On Thu, Jul 13, 2017 at 2:54 AM, Christudasan D <xander.cd at gmail.com> wrote: > Thank you Teresa. > > Yes, I would like to save the IR (*.bc and/or *.ll) after all > optimizations (especially thinLTO) are done and call *llc* separately. > Is there any specific document available online to see more about this > feature and various command-line switches that a compiler developer can > take advantage of? > It would help us to enable this feature for a custom architecture. > Unfortu...

On Thu, Jul 13, 2017 at 8:37 AM, Christudasan D <xander.cd at gmail.com> wrote: > > Hi Teresa, > > Yes, we plan to have our code at CG directly. > We use our own linker. That's the pain. We might only get a partial > benefit of thinLTO which occurs at compile time. > There is no compile-time only benefit of ThinLTO. You'll need the linker to interface with the LTO API for either ThinLTO or LTO to work. Unless you use internal tools to get native objects from ThinLTO, and feed those to your linker. But that is not a suppor...