We have been reconstructing/rematerializing uniforms for a while, but we
can do this in more scenarios, namely instructions which result is
immutable along the execution of a shader across all channels.
By doing this we gain the capacity to eliminate TMU spills which not
only are slower, but can also make us drop to a fallback compilation
strategy.
Shader-db results show a small increase in instruction counts caused
by us now being able to choose preferential compiler strategies that
are intended to reduce TMU latency. In some cases, we are now also
able to avoid dropping thread counts:
total instructions in shared programs: 12658092 -> 12659245 (<.01%)
instructions in affected programs: 75812 -> 76965 (1.52%)
helped: 55
HURT: 107
total threads in shared programs: 416286 -> 416412 (0.03%)
threads in affected programs: 126 -> 252 (100.00%)
helped: 63
HURT: 0
total uniforms in shared programs: 3716916 -> 3716396 (-0.01%)
uniforms in affected programs: 19327 -> 18807 (-2.69%)
helped: 94
HURT: 50
total max-temps in shared programs: 2161796 -> 2161578 (-0.01%)
max-temps in affected programs: 3961 -> 3743 (-5.50%)
helped: 80
HURT: 24
total spills in shared programs: 3274 -> 3266 (-0.24%)
spills in affected programs: 98 -> 90 (-8.16%)
helped: 6
HURT: 0
total fills in shared programs: 4657 -> 4642 (-0.32%)
fills in affected programs: 130 -> 115 (-11.54%)
helped: 6
HURT: 0
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15710>
Iago Toral Quiroga
cf4b3cb563