On Tue, Oct 29, 2013 at 12:36 PM, Eric Anholt <e...@anholt.net> wrote: > Matt Turner <matts...@gmail.com> writes: > >> Helps a lot of Steam games. >> >> total instructions in shared programs: 1287432 -> 1287130 (-0.02%) >> instructions in affected programs: 21447 -> 21145 (-1.41%) > > 13-15 are also: > > Reviewed-by: Eric Anholt <e...@anholt.net> > > I'm spending a while thinking about the if->sel passes. Having 2 seems > ridiculous, but I haven't come up with a good alternative.
I planned to remove the other at the conclusion of this series, but the other operates (for better or worse, unknown) before pull constants are lowered so it handles a lot of things that it wouldn't be able to handle later if it happened later. I'll test your "i965/fs: Drop our dead push constants ..." later today with the hope that it drops all of the pull constants in the relevant shaders, allowing my pass to handle all of the things the existing one does. Reminder (and for everyone else): currently the shaders that the old pass handles that mine doesn't, do things like IF MOV dst src0 ELSE MOV dst src1 ENDIF where src0 is a uniform that winds up being a pull constant, so after pull constants are lowered it looks like: IF SEND tmp MOV dst tmp ELSE MOV dst src1 ENDIF Possibly badly, the existing pass causes the final code to be an unpredicated SEND and a SEL between tmp and src1. Longer term, I think a pass that converts if blocks to predicated instructions might help. The difficulty I see is that predicating instructions that may be skipped entirely by an IF instruction (if all of the channels go the same way) may be worse, especially if we know that the comparison is uniformly constant. But hopefully your patch just avoids this problem entirely. I'll provide an update later. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
