In the past where backends had to deal with nir_register we needed
a specific path for them here because nir_def_components_read only
worked on ssa defs, but now that we got rid of nir_register we
only have nir_def and we don't need to go out of our way to do this
and we can just always use nir_def_components_read.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28978>
This is similar to what we do for textures where we program a number
of channels matching the number of componentes actually read by the
shader.
Makes tests like dEQP-VK.image.load_store.with_format.2d.r32_uint
drop from 18 instructions to 14 by emitting a single ldtmu instead
of 4.
From dEQP-VK.image.load_store.*:
total instructions in shared programs: 12681 -> 12093 (-4.64%)
instructions in affected programs: 4866 -> 4278 (-12.08%)
helped: 256
HURT: 0
helped stats (abs) min: 1 max: 4 x̄: 2.30 x̃: 2
helped stats (rel) min: 4.76% max: 25.00% x̄: 12.35% x̃: 11.11%
95% mean confidence interval for instructions value: -2.40 -2.19
95% mean confidence interval for instructions %-change: -12.99% -11.71%
Instructions are helped.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28978>
