ir3/ra: make main shader reg select independent of preamble

ir3_ra allocates registers in a round-robin fashion to avoid false
dependencies. In order to do this, it keeps track of a "file start"
register for each register file and will search starting from there for
available registers.

This file start is initialized at the beginning of RA of kept across
blocks, including across the preamble. This means that a change that
only affects the preamble may cause changes in how registers are
allocated in the main shader. This may result in more or less copies,
and more or less false dependencies which changes the behavior of
postsched.

Changes in the preamble affecting the main shader makes it more
difficult to analyze shader-db results, as I often find myself chasing
down a regression that is just caused by RA/postsched "bad luck" in a
main shader that didn't actually change. Prevent this by resetting the
file start at the beginning of the main shader.

Totals:
Instrs: 364710030 -> 364631384 (-0.02%); split: -0.19%, +0.17%
CodeSize: 926766046 -> 926671488 (-0.01%); split: -0.10%, +0.09%
NOPs: 47703035 -> 47653319 (-0.10%); split: -1.05%, +0.94%
MOVs: 17072354 -> 17075112 (+0.02%); split: -1.28%, +1.29%
COVs: 4098062 -> 4096784 (-0.03%); split: -0.04%, +0.01%
Full: 15164359 -> 15112404 (-0.34%); split: -0.34%, +0.00%
(ss): 7818796 -> 7819147 (+0.00%); split: -1.10%, +1.11%
(sy): 3985674 -> 3983435 (-0.06%); split: -0.72%, +0.67%
(ss)-stall: 26535279 -> 26525929 (-0.04%); split: -1.36%, +1.32%
(sy)-stall: 111983489 -> 111716382 (-0.24%); split: -1.26%, +1.02%
Last helper: 116734916 -> 116595531 (-0.12%); split: -0.62%, +0.50%
Cat0: 53338794 -> 53289450 (-0.09%); split: -0.94%, +0.85%
Cat1: 22352349 -> 22328303 (-0.11%); split: -1.28%, +1.17%
Cat2: 155348173 -> 155348012 (-0.00%); split: -0.00%, +0.00%
Cat7: 9314194 -> 9309099 (-0.05%); split: -0.88%, +0.82%

Totals from 224302 (16.59% of 1352016) affected shaders:
Instrs: 148838101 -> 148759455 (-0.05%); split: -0.47%, +0.42%
CodeSize: 404838970 -> 404744412 (-0.02%); split: -0.22%, +0.20%
NOPs: 26261983 -> 26212267 (-0.19%); split: -1.90%, +1.71%
MOVs: 8372715 -> 8375473 (+0.03%); split: -2.60%, +2.63%
COVs: 2061488 -> 2060210 (-0.06%); split: -0.09%, +0.02%
Full: 3420300 -> 3368345 (-1.52%); split: -1.52%, +0.00%
(ss): 3848423 -> 3848774 (+0.01%); split: -2.24%, +2.25%
(sy): 2021040 -> 2018801 (-0.11%); split: -1.43%, +1.32%
(ss)-stall: 13554064 -> 13544714 (-0.07%); split: -2.65%, +2.59%
(sy)-stall: 59778475 -> 59511368 (-0.45%); split: -2.36%, +1.91%
Last helper: 52847662 -> 52708277 (-0.26%); split: -1.38%, +1.12%
Cat0: 29270336 -> 29220992 (-0.17%); split: -1.72%, +1.55%
Cat1: 10820261 -> 10796215 (-0.22%); split: -2.63%, +2.41%
Cat2: 57289060 -> 57288899 (-0.00%); split: -0.00%, +0.00%
Cat7: 5686726 -> 5681631 (-0.09%); split: -1.43%, +1.34%

Signed-off-by: Job Noorman <jnoorman@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37003>

0 files changed, 0 insertions, 0 deletions