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authorMatt Turner <[email protected]>2014-09-27 10:34:56 -0700
committerMatt Turner <[email protected]>2014-09-30 17:09:34 -0700
commit94b68109fbe1cb60cc23a4c5a319039ada81ea81 (patch)
tree9bfc35ffd2b2bca4f480a6d81b8aba59c662f42a
parentb52126b44f40643aa2c0986c1d51330f4e4130b5 (diff)
i965/fs: Optimize sqrt+inv into rsq.
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 <[email protected]> Reviewed-by: Ian Romanick <[email protected]>
-rw-r--r--src/mesa/drivers/dri/i965/brw_fs.cpp11
1 files changed, 11 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index ab4ee34b41c..19e9cb957e0 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -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;
}