[Mesa-dev] Mesa (master): mesa: document instructions ir_to_mesa emits

[Ian Romanick]

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On 05/09/2011 11:03 AM, Marek Olšák wrote:
> Module: Mesa
> Branch: master
> Commit: 801fbdf286bed58435ca3a9008104b098717ed9b
> URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=801fbdf286bed58435ca3a9008104b098717ed9b
> 
> Author: Marek Olšák <maraeo at gmail.com>
> Date:   Mon May  9 18:18:56 2011 +0200
> 
> mesa: document instructions ir_to_mesa emits
> 
> GLSL stopped using:
>    BRA, EXP, LOG, LRP, NRM3, NRM4, XPD.
> 
> GLSL started using:
>    KIL, SCS, SSG, SWZ.
> (omg why SWZ? isn't proc_src_register flexible enough?)

The problem is that some architectures (e.g., Nvidia, i965) can only use
that flexibility with the special SWZ instruction.  As far as I'm aware,
the back-ends for architectures that can use that flexibility (e.g.,
i915) aren't expecting it.  I'm not sure prog_exec will work with that
either.

> GLSL doesn't use these opcodes some Radeons do support:
>    ARR, DP2A, DST, LRP, XPD.
> 
> These opcodes are now unused:
>    AND, NOT, NRM3, NRM4, OR, XOR.
> (plus maybe the NV extensions which are unused by Gallium)
> 
> In addition to that, we don't use two-dimensional indirect addressing,
> which the Mesa IR can do.

You mean things like:

	MOV	R0, array[A0.x + 5];
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