Possible fix to _mesa_remove_extra_moves function in shader/prog_optimize.c (request testing)

[Brian Paul]

Conn Clark wrote:
> Hello,
> 
> Here is a possible fix/hack to get _mesa_remove_extra_moves function
> in shader/prog_optimize.c usable. As far as I could tell with my
> testing there was an issue with this optimizing pass and OPCODE_MUL .
> I just added an exception to for this one instruction and made it easy
> to add others should further testing indicate they need to be added
> too.
> 
> It bumped my Nexuiz scores on demo1 from 5,8,and 12 to 5,9, and 13. It
> also reduced the testing runtime from 234 seconds to 225 seconds.
> 
> 
> I have only tested on my radeon hd 3100 based laptop but would like to
> hear results from other types of cards too.

I'm a bit nervous about enabling that function without a _lot_ more 
testing.  And any special case added for MUL would seem to apply to 
any ALU instruction.  That tells me that there's probably other issues 
to shake out of the code before we can enable it.

If you're interested, you should at least run the glean and piglits 
tests which exercise shaders and GPU programs.

-Brian