[Mesa-dev] [PATCH 3/4] radeonsi: add more unlikely() uses into si_draw_vbo

[Marek Olšák]

On Wed, Sep 7, 2016 at 11:47 AM, Michel Dänzer <michel at daenzer.net> wrote:
> On 07/09/16 06:02 PM, Marek Olšák wrote:
>>
>> Based on the comments so far, it looks like all annotations in the
>> patch are very well placed, so I don't know what the fuss is about.
>
> As I said, there's no question about the first three annotations, but
> for the last two we can't know whether they help or actually hurt
> without measuring it. That's the whole point.

OK. The last two are so rare that their likeliness is below 1%. The
conditions are true when discarding CMASK or DCC, changing the micro
tile mode of a texture, reallocating texture storage, and degrading
the tile mode to linear. Some of those are caused by SDMA doing a
whole-layer overwrite, a texture transfer, or a buffer handle export.
Some of them can occur only once during the lifetime of a texture.
They are very rare during normal gaming, which just consists of state
changes and draw calls and nothing in between. I don't know about
microbenchmarks.

Marek