KonstantinSeurer
/
mesa
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

i965/fs: Relax interference check in register coalescing. 

A similar attempt was made in commit 5ff1e446 and was reverted in commit
a39428cf after causing a regression in an ES 3 conformance test. The
test still passes after this commit.

total instructions in shared programs: 1994827 -> 1992858 (-0.10%)
instructions in affected programs:     128247 -> 126278 (-1.54%)
GAINED:                                0
LOST:                                  1

Acked-by: Kenneth Graunke <kenneth@whitecape.org>
This commit is contained in:
Matt Turner 2014-07-08 12:13:27 -07:00
parent 1d97212007
commit 83214edf8a
1 changed files with 12 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp
View File

@ -118,24 +118,25 @@ can_coalesce_vars(brw::fs_live_variables *live_intervals,
if (!live_intervals->vars_interfere(var_from, var_to))
return true;
/* We know that the live ranges of A (var_from) and B (var_to)
* interfere because of the ->vars_interfere() call above. If the end
* of B's live range is after the end of A's range, then we know two
* things:
* - the start of B's live range must be in A's live range (since we
* already know the two ranges interfere, this is the only remaining
* possibility)
* - the interference isn't of the form we're looking for (where B is
* entirely inside A)
*/
if (live_intervals->end[var_to] > live_intervals->end[var_from])
int start_to = live_intervals->start[var_to];
int end_to = live_intervals->end[var_to];
int start_from = live_intervals->start[var_from];
int end_from = live_intervals->end[var_from];
/* Variables interfere and one line range isn't a subset of the other. */
if ((end_to > end_from && start_from < start_to) ||
(end_from > end_to && start_to < start_from))
return false;
int start_ip = MIN2(start_to, start_from);
int scan_ip = -1;
foreach_in_list(fs_inst, scan_inst, instructions) {
scan_ip++;
if (scan_ip < start_ip)
continue;
if (scan_inst->is_control_flow())
return false;