fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2025-12-27 23:30:10 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

freedreno/ir3: Call nir_opt_find_array_copies().

Browse source 
gfxbench vk-5-normal has a shader that sampels into a texels[] array at
the top, then in a loop calls a GLSL function passing texels[] in by
value.  This resulted in a copy to a temp inside the loop, which got
lowered to scratch stores since it was pretty big.

By doing find_array_copies(), we notice that it's equivalent to
copy_deref, then get to copy-propagate from the array at the top.  Then we
only have to set up the scratch array outside of the loop and load_scratch
from it in the called function inside the loop.  This also causes there to
be less spilling, stps 1144 -> 354 and ldps 826->36.

However, it doesn't seem to change performance on the test.  So, while
this seems to be an improvement for the shader, and we could maybe even do
better by rematerializing the txl samples inside the loop instead of
storing the texture fetches to scratch in the first place, it doesn't
currently seem worth pursuing more optimization of this shader.

No change on freedreno shader-db.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15982>
This commit is contained in:
Emma Anholt 2022-04-15 12:08:07 -07:00 • committed by Marge Bot
parent 7ba0c44607
commit 1bcd848816
1 changed files with 7 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

9
src/freedreno/ir3/ir3_nir.c
View file

@ -81,8 +81,6 @@ ir3_optimize_loop(struct ir3_compiler *compiler, nir_shader *s)
progress = false;
OPT_V(s, nir_lower_vars_to_ssa);
progress |= OPT(s, nir_opt_copy_prop_vars);
progress |= OPT(s, nir_opt_dead_write_vars);
progress |= OPT(s, nir_lower_alu_to_scalar, NULL, NULL);
progress |= OPT(s, nir_lower_phis_to_scalar, false);
@ -90,6 +88,11 @@ ir3_optimize_loop(struct ir3_compiler *compiler, nir_shader *s)
progress |= OPT(s, nir_opt_deref);
progress |= OPT(s, nir_opt_dce);
progress |= OPT(s, nir_opt_cse);
progress |= OPT(s, nir_opt_find_array_copies);
progress |= OPT(s, nir_opt_copy_prop_vars);
progress |= OPT(s, nir_opt_dead_write_vars);
static int gcm = -1;
if (gcm == -1)
gcm = env_var_as_unsigned("GCM", 0);
@ -165,6 +168,8 @@ ir3_optimize_loop(struct ir3_compiler *compiler, nir_shader *s)
progress |= OPT(s, nir_opt_remove_phis);
progress |= OPT(s, nir_opt_undef);
} while (progress);
OPT(s, nir_lower_var_copies);
}
static bool