[Mesa-dev] [PATCH] i965/fs: Don't try 16-wide if 8-wide uses more than half the registers.

[Matt Turner]

On Wed, Aug 22, 2012 at 5:32 PM, Ian Romanick <idr at freedesktop.org> wrote:
> On 08/21/2012 10:49 PM, Eric Anholt wrote:
>> I don't like the idea of losing 16-wide on apps where it might have
>> succeeded if we just tried.  Note that a chunk of register space gets
>> eaten by things that don't scale with number of pixels, like attribute
>> setup, push constants, and the MRF hack.
>
>
> I think that's part of the reason he pick 75% usage as the cut-off instead
> of 50%.

Actually, I think he picked 75 because it was the smallest shader in
L4D2 that failed to compile for 16-wide.