[Mesa-dev] wider registers in llvmpipe

[Stéphane Marchesin]

On Mon, Oct 8, 2012 at 6:25 AM, Jose Fonseca <jfonseca at vmware.com> wrote:
>
>
> ----- Original Message -----
>> On Sun, Oct 7, 2012 at 3:37 PM, Stéphane Marchesin
>> <stephane.marchesin at gmail.com> wrote:
>> > On Wed, Jul 18, 2012 at 8:35 AM, Jose Fonseca <jfonseca at vmware.com>
>> > wrote:
> [...]
>> >> I can't reproduce the failures here neither, nor with softpipe +
>> >> draw llvm
>> >>
>> >> I also considered that this could be 32bits specific, but that
>> >> doesn't seem to be the case.  It seems i915g specific AFAICT.
>> >>
>> >> Stephane I'll gonna need to to provide more details (in
>> >> particular, stack dump of the crashes, dumps w/
>> >> GALLIVM_DEBUG=tgsi,ir,asm environment var before/after this
>> >> change, see if not advertise half float solve the issue) to pin
>> >> point this. If you wanna open a bug and follow this on fdo that's
>> >> fine by me.
>> >>
>> >
>> > Unearthing an old item now that I have time for it. I can reproduce
>> > with llvmpipe on the same machine, hopefully the backtrace rings a
>> > bell, I'll also try to dig further into it. Running draw-vertices
>> > in
>> > gdb I get:
>>
>> So I dug into it a bit more, and this seems to be an LLVM 2.8 issue.
>> LLVM 3.1 works fine here. I think we should just disallow LLVM <=
>> 2.8.
>
> Ok. Good to know.
>
> LLVM 2.8 has several known issues. If your LLVM build doesn't include the fixes from http://cgit.freedesktop.org/~jrfonseca/llvm/log/?h=backports_28 then it is possible that one of them is the culprit here.
>
> If you look at http://cgit.freedesktop.org/~jrfonseca/llvm/log/?h=backports_31 you'll see that vanilla LLVM 3.1 is not perfect either. No unpatched version is.
>
> Either way, I'm fine if you want to require 2.9+ on automake.
>

Ok, I think I'll send a patch to add that then. Maybe also stop
allowing i915g without llvm.

> But I need to continue support LLVM 2.6 on scons for a bit longer.

I'm really sorry about that :)

Stéphane