brw/reg_allocate: Optimize spill offset calculation using integer MAD
Gfx12.5 and later allow the use of two 16-bit immediate values in
integer MAD. Gfx11 and Gfx12 allow a single immediate for integer MAD,
but that is not helpful where.
v2: brw_reg_alloc::build_lane_offsets is only used on Gfx12.5+, so the
check around using integer MAD is unnecessary.
No shader-db or fossil-db changes on any pre-Gfx12.5 platforms.
shader-db:
Lunar Lake, Meteor Lake, and DG2 had similar results. (Lunar Lake shown)
total instructions in shared programs: 17119962 -> 17118441 (<.01%)
instructions in affected programs: 65398 -> 63877 (-2.33%)
helped: 32 / HURT: 0
total cycles in shared programs: 895433316 -> 895425578 (<.01%)
cycles in affected programs: 13437376 -> 13429638 (-0.06%)
helped: 30 / HURT: 2
fossil-db:
Lunar Lake, Meteor Lake, and DG2 had similar results. (Lunar Lake shown)
Totals:
Instrs: 210052706 -> 209550074 (-0.24%)
Cycle count: 31486266412 -> 31436238696 (-0.16%); split: -0.16%, +0.00%
Totals from 7081 (1.00% of 707082) affected shaders:
Instrs: 16864614 -> 16361982 (-2.98%)
Cycle count: 6323185782 -> 6273158066 (-0.79%); split: -0.79%, +0.00%
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34886>
1 file changed
