similar to: RFC: Building GlobalISel by default

Hi Michael, > On Jan 13, 2017, at 6:38 PM, Michael Kuperstein <mkuper at google.com> wrote: > > As a person not developing on GlobalISel, I can already play with it by setting the flag. ;-) > > The main (and huge) benefit I see is that it will get tested by default. I agree. > So, I think it's mainly a question of maturity - if my (non-GlobalISel) change breaks

> On Jan 14, 2017, at 4:57 AM, Renato Golin via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > On 14 January 2017 at 01:54, Quentin Colombet via llvm-dev > <llvm-dev at lists.llvm.org> wrote: >> Now, four backends (if I am counting right: X86, ARM, AArch64, AMDGPU) are working on bringing-up GlobalISel, I’d like to switch the default of the LLVM_BUILD_GLOBAL_ISEL

Hi all, We had some internal discussions about flipping the default for O0 and we concluded that we wanted to postpone it. *** Why Is That? *** We don’t want to send the wrong message that GlobalISel’s design is set in stone and ready for broader adoption. In particular, 1. The APIs are still evolving and can still possibly change significantly 2. The TableGen backend to reuse the existing SD

Hi all, Following the thread from http://lists.llvm.org/pipermail/llvm-dev/2017-January/109029.html, I am sending this email to give a status on GlobalISel progress and situation. We are pushing GlobalISel from the state of prototype to a production quality framework. We welcome help with patches, reviews, feedbacks and so on. As explained during the last developer meeting, we are aiming at

Hi, GlobalISel, the SelectionDAG replacement, has come a long way since initially discussed on the mailing list and its last discussion at the EuroLLVM BoF (https://etherpad.net/p/GlobalISel <https://etherpad.net/p/GlobalISel>). We believe we are close to the point of enabling it by default on AArch64 at O0. We now would like to enlist your help to get there. *** Quick Status *** On iOS

Hi Quentin, My only remaining concern is around ABI compatibility. The following commit seems to indicate that in the previous round of evaluation, we didn’t find an existing ABI compatibility issue: http://llvm.org/viewvc/llvm-project?view=revision&revision=311388. I haven’t looked into the details of this issue - so maybe I’m worried over nothing? I’m wondering if since then on your side

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

Hi Quentin, I’ve started running an ABI test suite with global isel on AArch64, and while it hasn’t found any ABI issues it has hit an assertion in clang when using the __fp16 type. Here’s a reproducer: __fp16 pass_f16(__fp16 p) { return p; } $ /work/llvm/build/bin/clang --target=aarch64-arm-none-eabi -march=armv8-a -c test.c -O0 -mllvm -global-isel -mllvm -global-isel-abort=0

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

Great Quentin :). I've rerun the benchmarks comparing "-O0 -g" with "-O0 -g -mllvm -global-isel -mllvm -global-isel-abort=2" on r302453, on AArch64 Cortex-A57. I indeed see almost no moves between GPR and FPR registers anymore (see details below for where I still see some). On geomean, I see 13% slow down (down from 17% on my previous run). On geomean, code size increase

Hi Kristof, > On Apr 27, 2017, at 9:47 AM, Kristof Beyls <kristof.beyls at arm.com> wrote: > > Hi Quentin, > >> On 27 Apr 2017, at 00:48, Quentin Colombet <qcolombet at apple.com <mailto:qcolombet at apple.com>> wrote: >> >> Hi Kristof, >> >>> On Apr 6, 2017, at 6:53 AM, Kristof Beyls <kristof.beyls at arm.com

Hi Quentin, On Tue, May 9, 2017 at 11:47 AM Quentin Colombet via llvm-dev < llvm-dev at lists.llvm.org> wrote: > Hi Kristof, > > On May 9, 2017, at 3:41 AM, Kristof Beyls <kristof.beyls at arm.com> wrote: > > Great Quentin :). > > I've rerun the benchmarks comparing "-O0 -g" with "-O0 -g -mllvm > -global-isel -mllvm

To give an update here, we actually are not missing a mapping. The code complains because we are copying around a fp16 into a gpr32 and that shouldn’t be done with a copy (default mapping). I extended the repairing code to issue G_ANYEXT in those cases instead of asserting. However, now, I have to teach instruction select about those ANYEXT otherwise we’ll fallback in that case. But that’s a

Hi Oliver, Thanks for trying this. Could you file a different PR for each of the problem you found and reference the umbrella PR: http://llvm.org/PR35347? <http://llvm.org/PR35347?> Thanks, -Quentin > On Nov 17, 2017, at 8:17 AM, Oliver Stannard <oliver.stannard at arm.com> wrote: > > Hi Quentin, > > One more reproducer, this time with small (<64bit) values

Hi Kristof, > On Apr 6, 2017, at 6:53 AM, Kristof Beyls <kristof.beyls at arm.com> wrote: > > I've been digging a little bit deeper into the biggest performance regressions I've observed. > > What I've observed so far is: > * A lot of the biggest regressions are caused by unnecessarily moving floating point values through general purpose registers. I've

> On Jan 19, 2017, at 11:59 AM, Quentin Colombet <qcolombet at apple.com> wrote: > > Hi all, > > Trying to summarize the concerns along side my answers but I believe we are good to do the switch to build GlobalISel by default. In particular, Renato and I exchanged offline and he tried doing the switch on some of the bots he maintained and did not see any overhead/problem for

I've kicked off a run to compare "-O0 -g" versus "-O0 -g -mllvm -global-isel -mllvm -global-isel-abort=2". I've selected the test-suite (albeit a version which is a couple of months old now) and a few short-running proprietary benchmarks to get data back quickly for an initial feel of where things are. This was running on Cortex-A57 AArch64 Linux. I saw one assertion

On 12 June 2017 at 18:54, Diana Picus <diana.picus at linaro.org> wrote: > Hi all, > > I added a buildbot [1] running the test-suite with -O0 -global-isel. It > runs into the same 2 timeouts that I reported previously on this thread > (paq8p and scimark2). It would be nice to make it green before flipping the > switch. > > I did some more investigations on a machine

Hey Quentin, reads like you got the community nod and can start the engine … Cheers Gerolf > On Jan 24, 2017, at 5:10 PM, Eric Christopher via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > > > On Thu, Jan 19, 2017 at 1:10 PM Jim Grosbach <grosbach at apple.com <mailto:grosbach at apple.com>> wrote: >> On Jan 19, 2017, at 11:59 AM, Quentin Colombet

Thanks all. Amara, could you take a look? > On Nov 20, 2017, at 3:06 AM, Oliver Stannard <oliver.stannard at arm.com> wrote: > > Hi Quentin, > > I’ve raised: > https://bugs.llvm.org/show_bug.cgi?id=35359 <https://bugs.llvm.org/show_bug.cgi?id=35359> > https://bugs.llvm.org/show_bug.cgi?id=35360 <https://bugs.llvm.org/show_bug.cgi?id=35360> >