[Mesa-dev] TGSI thoughts

[Zack Rusin]

On Wednesday 28 July 2010 06:26:39 Marek Olšák wrote: 
> Going from GL2.1 to GL1.5 just because some hardware can't do ddx and ddy
> seems a bit silly to me.

I'm not quite sure what do you mean here, derivatives have been present in 
GLSL since 1.1 so realistically hardware without them can't support any 
version of GLSL.
  
> PS3.0 doesn't have address regs, that means there are no ARL/ARR/ARA
> opcodes. Are you sure these must be mandatory? Please see:
> http://msdn.microsoft.com/en-us/library/bb172920%28VS.85%29.aspx

I was saying that they are mandatory for Gallium, not that semantically they 
are mandatory for everyone (also as Keith pointed out they are there in 
VS3.0). Long term, especially with GPGPU it would probably make sense to make 
our indirect addressing more robust but for now it is what it is.

> PUSHA, POPA, and pack/unpack opcodes are not in SM3.0 either.

Like I said the pack/unpack are probably least useful from the list and kept 
largely for the "we might need them one day" reason. I don't think anyone 
would miss those but since no one really even touches them they don't seem to 
bother anyone badly enough to do something about it.

z