Re: [gnugo-devel] how influence influences owl

[Daniel Bump]

> Whew, --experimental-influences currently causes 70 PASSes and 104
> FAILS. Btw, after Dan had mentioned that regressions take only 12 hours on
> his Celeron-433, while they took ~24 h (that was including --owl-threats) on
> my K6-II 400, I realized that I might actually be so kind to my gcc to tell
> him about the processor. He returned the favor of adding the flag -m486 in
> engine/Makefile by producing a huge performance gain, appartently more than
> 1.5. Maybe we should add a hint in the INSTALL file that one should care
> about the $CFLAGS environment variable? At the moment this only mentioned in
> the ./configure --help output.

I don't quite understand. What exactly did you do?

Isn't your AMD processor a 686? How would adding a -m486 flag help in this
case?

> Among these FAILS are some owl failures which I do not understand. Can
> someone more owl-knowledgeable explain me how the influence function affects
> the owl code, and e.g. change the moves tried? That would be very helpful.

Through the escape values. Look at pattern A229. Whether or not this
is matched would depend on the influence function. See the function
compute_owl_escape_values() in owl.c, which calls the influence code.

Pattern A229

xx.O?        stop escape
x.*OX
...X.
-----

:8,-,value(80)

ac.O?
b.*OX
...X.
-----

;owl_escape_value(a) + owl_escape_value(b) + owl_escape_value(c) > 0

Dan