Sean (Jun 03 2020 at 22:55): Sean (Jun 03 2020 at 22:55):So I just re-ran a test and eliminating the register keyword everywhere (at least on mac 10.14) still results in a very slight but consistent performance decrease, approximately 1%.
starseeker (Jun 04 2020 at 00:52):Given it seems to be on its way out, standards wise, what options do we have?
Sean (Jun 04 2020 at 00:54):it's not on it's way out for C, that's a C++ thing. just means we should probably continue to ignore it and not add more intentionally.
Sean (Jun 04 2020 at 00:56):i'm sure at some point, if push comes to shove, we can just take the hit and remove it if we hit a maintenance issue. not like it's an issue. I just wanted to give a situational awareness update -- still amazingly providing some benefit with current compilers, which is the real surprise.
starseeker (Jun 04 2020 at 02:27):Although I admit we're a ways away, it'll most likely become an issue if we try to get the "build everything as C++" option working. Maybe we can preprocess it out for that case somehow?
Sean (Jun 04 2020 at 02:29):A simple #define register /**/ in config would make them all go poof. Not an issue.
Sean (Jun 04 2020 at 02:30):I think that's what was originally done, I think maybe used -Dregister=""
Sean (Jun 05 2020 at 03:51):It's worth noting that we seem to be a solid 25% slower than we were some time ago. I have vgr results spanning a broad gamut, with current optimized builds sitting right in the middle of the pack:
agua:.build morrison$ grep vgr bench/summary |awk '{print $9}' | sort -n
13756.42
14717.22
15413.82
15542.82
15788.07
15974.65
16610.00
16619.31
16810.47
17450.78
17922.01
18847.25
19818.99
21523.09
31678.95
31773.81
33843.48
33974.45
33988.44
34024.96
34287.17
34377.16
36554.54
38227.29
38659.17
39677.67
39860.67
39976.24
40401.68
41149.49
42381.23
44658.15
46135.64
The teens are simply default unoptimized builds and are to be expected. Current optimized is in the 34k ballpark, yet I clearly have had significantly faster builds, more typically in the 40k range.
Trying an pgo build.
Sean (Jun 05 2020 at 16:49):Ugh, PGO build is actually showing 10% slower... will have to dig deeper.
Sean (Jun 05 2020 at 16:49):30k
Last updated: Oct 09 2024 at 00:44 UTC