[Mesa-dev] [PATCH] gallium: remove TGSI_OPCODE_KILL

[Roland Scheidegger]

Am 06.10.2017 um 00:34 schrieb Marek Olšák:
> On Thu, Oct 5, 2017 at 8:00 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>> On Thu, Oct 5, 2017 at 1:45 PM, Marek Olšák <maraeo at gmail.com> wrote:
>>> On Thu, Oct 5, 2017 at 4:45 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>>>> Like Roland, I don't see what's being gained. It's more code
>>>> everywhere and harder to read the TGSI directly.
>>>
>>> Harder to read the "IMM" string in the operand?
>>
>> Yeah. You see a KILL_IF IMM[]... and then have to look up what that
>> immediate is among the 75 other immediates. For all you know it's not
>> -1 but something else. For long programs, this isn't great, esp if
>> you're matching things up to the GLSL.
>>
>>>
>>> "more code everywhere"?
>>> 21 files changed, 22 insertions(+), 200 deletions(-)
>>>
>>> This is the reason: 200 deletions(-)
>>>
>>>>
>>>> Neither nv30 nor nv50+ do the checks you suggest.
>>>
>>> But they can if they want.
>>
>> ... thus leading to more code.
>>
>> Anyways, since my (recent) ability to contribute has greatly
>> atrophied, I'm not going to explicitly NAK this. But you have my 2c.
> 
> I don't really understand the backlash, and especially from nouveau it
> doesn't make sense. It's just a removal of a redundant instruction
> that simplifies driver code for me. So far nobody asked me to check
> IMM in drivers and keep the old codepath there. Yes, KILL_IF is silly,
> but it's a superset of both.
> 

MAD is a superset of MUL and ADD too.
(Ok maybe with precise that's not entirely true anymore, but I'm sure
you get the point.)

Roland