[fpc-devel] @Gareth - Feedback on optimizations

[Martin Frb]

Just thought this may be interesting.
Though the results are for "eyeballing" at best -- see the video linked 
in Jonas' recent mail:
https://lists.freepascal.org/pipermail/fpc-devel/2022-January/044336.html

I run my FpDebug test case with 3.2.3 and 3.3.1 (both early Dec)

The test runs about 15 secs (evaluating approx 70k watches).
The test was done with a modified FpDebug for single threaded execution 
(threaded results are similar, but have more variance)

Tests done with

FPC 3.2.3 -O2  :  14.1 - 14.3 sec
FPC 3.3.1 -O2  :  13.3 - 13.5 sec

FPC 3.2.3 -O-1 -gw3  :  15.0 - 15.2 sec
FPC 3.3.1 -O-1 -gw3   :  14.3 - 14.5 sec

So on my PC, with this particular compilation setting the speedup 
(intentional plus side-effects) is 4 to 5 percent.

I7- 8600K
Win 64 bit


Can't do 3.2.2 or 3.2.0 as they have that bug, that crashes fpdebug.
https://gitlab.com/freepascal.org/fpc/source/-/commit/e9d318e7e2f772bf455a92461cd5c229e69858d8