similar to: [GlobalISel] Quick Status

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 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

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, I would like to get rid of the logic around disabling GlobalISel from the build. *** Context *** So far, GlobalISel has been this framework built up on the side for about two years. Now, we are close to a point where having it being optional impedes our ability to implement the right things. For instance, checks that would fit naturally in the MachineVerifier are directly done during the

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

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 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

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 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

Hi Quentin, Hi Amara, I was following your discussion on D75086 regarding declaring types as legal even if they are smaller than the actual register class (e.g. s16 and gpr32). We are working on a backend which only has 32 and 64-bit registers and we recently had a problem regarding exactly this where we had to declare G_UNMERGE_VALUES and G_MERGE_VALUES with a smaller type of <s32 as

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 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 Quentin, thank you for the reply! This clears up a lot of the questions I was having. It seems like we should definitely invest some time in rewriting some of our legalization rules then! I also posted some questions further down below. I would appreciate getting your opinion on them. > Hi Dominik, > > I’ll do a brief reply here and if you want more information we can talk further

Looks like there are a lot of opinions where memcpy expansion/inlining needs to happen: (late) IR, or if it is a backend problem, see also for example https://reviews.llvm.org/D35035. Complicating factor here is that efficient memcpy lowering is crucial for performance and code-size (and they occur a lot). Either way, I agree that the TLI hooks are not SelectionDAG specific, they can be used in

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> >

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

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

Hi all, 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 variable in CMake, such that the framework gets built by default. ** Impact of Flipping the Switch ** * Upsides * For people developing on GlobalISel, it will: - Simplify the CMake command to type :) - Build/Test