summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorAlejandro PiƱeiro <[email protected]>2015-09-11 12:21:13 +0200
committerEduardo Lima Mitev <[email protected]>2015-09-11 17:43:22 +0200
commitd4e29af2344c06490913efc35430f93a966061bb (patch)
tree138aea6b2927aebbf1a37b4d4e987aeb89d5ddbf
parent2c52c794d727e535c1baca671a7c1e5b38dffb00 (diff)
i965/vec4: check writemask when bailing out at register coalesce
opt_register_coalesce stopped to check previous instructions to coalesce with if somebody else was writing on the same destination. This can be optimized to check if somebody else was writing to the same channels of the same destination using the writemask. Shader DB results (taking into account only vec4): total instructions in shared programs: 1781593 -> 1734957 (-2.62%) instructions in affected programs: 1238390 -> 1191754 (-3.77%) helped: 12782 HURT: 0 GAINED: 0 LOST: 0 v2: removed some parenthesis, fixed indentation, as suggested by Matt Turner v3: added brackets, for consistency, as suggested by Eduardo Lima Reviewed-by: Matt Turner <[email protected]>
-rw-r--r--src/mesa/drivers/dri/i965/brw_vec4.cpp10
1 files changed, 6 insertions, 4 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp
index 893ff356afa..c4da1a11be8 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp
@@ -1090,11 +1090,13 @@ vec4_visitor::opt_register_coalesce()
if (interfered)
break;
- /* If somebody else writes our destination here, we can't coalesce
- * before that.
+ /* If somebody else writes the same channels of our destination here,
+ * we can't coalesce before that.
*/
- if (inst->dst.in_range(scan_inst->dst, scan_inst->regs_written))
- break;
+ if (inst->dst.in_range(scan_inst->dst, scan_inst->regs_written) &&
+ (inst->dst.writemask & scan_inst->dst.writemask) != 0) {
+ break;
+ }
/* Check for reads of the register we're trying to coalesce into. We
* can't go rewriting instructions above that to put some other value