fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2025-12-25 00:00:11 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

i965/fs: Optimize sqrt+inv into rsq.

Browse source 
Transform

   sqrt a, b
   rcp  c, a

into

   sqrt a, b
   rsq  c, b

The improvement here is that we've broken a dependency between these
instructions. Leads to 330 fewer INV instructions and 330 more RSQ.

Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
This commit is contained in:
Matt Turner 2014-09-27 10:34:56 -07:00
parent b52126b44f
commit 94b68109fb
1 changed files with 11 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
src/mesa/drivers/dri/i965/brw_fs.cpp
View file

@ -2334,6 +2334,17 @@ fs_visitor::opt_algebraic()
}
}
break;
case SHADER_OPCODE_RCP: {
fs_inst *prev = (fs_inst *)inst->prev;
if (prev->opcode == SHADER_OPCODE_SQRT) {
if (inst->src[0].equals(prev->dst)) {
inst->opcode = SHADER_OPCODE_RSQ;
inst->src[0] = prev->src[0];
progress = true;
}
}
break;
}
default:
break;
}