> Am 18.10.2025 um 08:28 schrieb Thomas Schwinge <[email protected]>:
>
> Hi!
>
>> On 2025-10-17T15:55:44+0100, Andrew Stubbs <[email protected]> wrote:
>>> On 17/10/2025 15:35, Thomas Schwinge wrote:
>>> On 2025-09-09T16:52:57+0000, Andrew Stubbs <[email protected]> wrote:
>>>> The previous definition had all the GFX11 register counts doubled to fix a
>>>> bug
>>>> that was encountered in early testing. This seems to have been a
>>>> misunderstanding of the problem (which is no longer reproducible).
>>>
>>> I can't comment on the historic aspects, but I can tell that since this
>>> commit r16-3726-g7bc2e311688ac279f1abc2a47944e5b763f7ec89
>>> "amdgcn: fix GFX10/GFX11 VGPR counts", '-march=gfx1100' testing is
>>> completely broken; nothing but:
>>>
>>> Memory access fault by GPU node-2 (Agent handle: [...]) on address
>>> (nil). Reason: Page not present or supervisor privilege.
>>>
>>> May I 'git push' my 'git revert', or should I keep that local, awaiting
>>> your investigation?
>>
>> It works for me!??????
>
> Mystery resolved: I was using LLVM 15 tools (GNU Guix 15.0.7) vs. Andrew
> using some "21.0.0git" version. Step-wise upgrading (GNU Guix): 16.0.6,
> 17.0.6, 18.1.8 still fail in the same way, but then with 19.1.7 it's good
> once again.
>
> How to proceed? LLVM 19 has been released just one year ago, in summer
> 2024. Is that too recent to require ("for users of affected
> configurations", which I can't tell which exactly those are)? We could
> go back to the previous GCC/GCN code generation -- maybe conditionally on
> the LLVM version available, or conditionally on a feature/bug fix
> 'configure'-time check yet to be determined?
I think requiring LLVM 19 or up is fine. It _is_ annoying that we need to tap
into those tools for assembler/linker. Which part is the issue here?
Assembler or linker?
Richard
>
>
> Grüße
> Thomas
>
>
>> I'm aware of PR121393, but that only affects the "for-<n>" testcases
>> (and was exposed by the vectorization improvements, not this).
>>
>>>
>>>
>>> Shouldn't the commit you pushed also have removed the following from
>>> 'gcc/config/gcn/gcn.cc:gcn_hsa_declare_function_name':
>>>
>>> fprintf (file,
>>> ".kd\n"
>>> [...]
>>> " .vgpr_count: %i%s\n"
>>> [...], next_free_vgpr,
>>> (TARGET_WAVE64_COMPAT
>>> ? " ; wavefrontsize64 counts double on SIMD32"
>>> : ""));
>>
>> Good catch. It's just a comment though.
>>
>> Andrew
