fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2026-04-21 03:20:40 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

nir/deref: Rematerialize parents in rematerialize_derefs_in_use_blocks

Browse source 
When nir_rematerialize_derefs_in_use_blocks_impl was first written, I
attempted to optimize things a bit by not bothering to re-materialize
the sources of deref instructions figuring that the final caller would
take care of that.  However, in the case of more complex deref chains
where the first link or two lives in block A and then another link and
the load/store_deref intrinsic live in block B it doesn't work.  The
code in rematerialize_deref_in_block looks at the tail of the chain,
sees that it's already in block B and skips it, not realizing that part
of the chain also lives in block A.

The easy solution here is to just rematerialize deref sources of deref
instructions as well.  This may potentially lead to a few more deref
instructions being created by the conditions required for that to
actually happen are fairly unlikely and, thanks to the caching, it's all
linear time regardless.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109603
Fixes: 7d1d1208c2 "nir: Add a small pass to rematerialize derefs per-block"
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
(cherry picked from commit 9e6a6ef0d4)
This commit is contained in:
Jason Ekstrand 2019-02-10 22:23:01 -06:00 • committed by Emil Velikov
parent a9c0e146ef
commit 3545986962
1 changed files with 2 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
src/compiler/nir/nir_deref.c
View file

@ -490,10 +490,9 @@ nir_rematerialize_derefs_in_use_blocks_impl(nir_function_impl *impl)
_mesa_hash_table_clear(state.cache, NULL);
nir_foreach_instr_safe(instr, block) {
if (instr->type == nir_instr_type_deref) {
nir_deref_instr_remove_if_unused(nir_instr_as_deref(instr));
if (instr->type == nir_instr_type_deref &&
nir_deref_instr_remove_if_unused(nir_instr_as_deref(instr)))
continue;
}
state.builder.cursor = nir_before_instr(instr);
nir_foreach_src(instr, rematerialize_deref_src, &state);