Use log() instead because we are not in speed
critical paths.
Also a bit of renaming and code shuffle while there.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Has been remained the same from ages also with the FIXME.
Retire for now and rearrange the conditions order for
maximum performance.
Also a small touch at null zugzwang verification.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It is more up to the point. Also small speedup
due to checking for threat move before calling
the function. This saves more then 90% of function calls.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
In 44% of cases we call search() just to call
qsearch() one moment later, avoid this double dispatch.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
And avoid a redundant one passed as argument in
search calls.
Also renamed gamePly in ply to better clarify this
is used as search ply and is set to zero at the
beginning of the search.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
In RootMoveList c'tor we call qsearch() with
ply == 1 but SearchStack at 0.
We never noticed before because in qsearch we don't access
previous's ply SearchStack, otherwise we would have got
a nice crash ;-)
This bug is a fall down of previous patch.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Use a pointer to current SearchStack to avoid ss[ply]
address calculation.
Gives 1% speedup on Intel compiler
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
In case tte->depth() is far lower the current depth
and we are in a PV node.
Almost 45% of researches give a different ttMove !
After 999 games at 1+0
Mod vs Orig +174 =694 -131 +15 ELO !!!!!!!
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Do not search immediately at full depth, but try a second
chance at lower depth. This is a feature that should scale
well because become important at high depths where we have
big reductions and also big savings in avoiding a costly
full depth search.
After 942 games at 1+0
Mod vs Orig +158 =645 -139 +7 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It does not seem to increase anything even with a QUAD,
so revert.
After 1000 games with a QUAD
Mod - Orig: 500 - 497 (+1 elo)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
No gain in the worst case of 2 threads, but also no
loss and good potential for QUAD or OCTAL machines.
After 922 games at 1+0 with 2 threads
Mod vs Orig +143 =533 -143 +0 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Function split() doesn't need to return a value, also
remove useless 'master' field.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It is redundant with splitPoint->slaves[].
Also move slaves[MAX_THREADS] among the shared data in
SplitPoint definition as it should have been already.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Small twekas to make the two searches as similar as
possible.
Also removed an useless setting of mateKiller in sp_search()
No functional change (tested with FakeSplit)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We don't need to comment/uncomment code, just
set FakeSplit bool to true to enable faked split.
Also reintroduced some asserts and cleaned up a bit.
Tested that with FakeSplit = true we have reproducible
finger printing even in SMP.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Also introduce a new rule:
In sp_search() always must hold: sp->alpha < sp->beta
Should fix some rear but very nasty races
To keep everything in sync, search() is also modified to
obey this rule. Because this affects only PV-nodes, should
have zero meaning to speed.
No functional change in fake mode
Regression test after 854 games
Mod vs Orig 433 - 421, no crashes.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We don't need to evaluate the position if it
is already cached in TT. We already do this
in non-PV case.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This is what actually is.
A standard naming convention suggests to name a variable
with someting resembling _what_ the variable is and not
_how_ the variable is used. This normally results
in easier to read code.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
More aggressive LMR reductions.
Tested at different time controls:
- Tested with 1CPU 1+0, after 3000 games, result was +12 ELO
- Tested this with 4CPU 1+0 and got sth around 5-10 ELO increase
- Last one at long time control,after ~1000 games with 10+0 result is:
Orig - Mod: 491 - 520 (+10 elo)
A testing marathon by Joona for this important change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Master thread returns from idle_loop() when sp->cpus == 0,
but cpus is decremented by slave threads under sp->lock,
so it could happen that we return in split(), where we release
the split point, with sp->lock still held.
This patch guarantees that sp->lock is released when returning
to split().
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Almost no change and simplifies a bit the code.
After 961 games at 1+0
Mod vs Orig +156 =650 -146 +4 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Re-save the same TT entry if value is usable and allow
us to cut-off, it means that entry is valuable and
we want to keep it fresh updating the 'generation'
parameter up to the current value.
Patch suggested by J. Wesley Cleveland and better
clarified by Miguel A. Ballicora.
After 999 games at 1+0 64MB hash size
Mod vs Orig +167 =677 -155 +4 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Should be a very minor change, but there is a small
functional change because futility_margin() is used in more
places then in the pruning formula.
After 999 games at 1+0
Mod vs Orig +167 =678 -154 +5 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Revert all the patches that introduced the change and
more or less fixed the zugzwang issue.
There is a gain against last current version and we
can remove a lot of code.
After 979 games at 1+0 on my QUAD
Mod vs Orig +152 =688 -139 +5 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Real search is considered of higher quality then null
search one.
This allows to fix the zugzwang issue with a minimal
impact on ELO.
Zugzwang verified on position:
8/7P/8/8/K2b4/p7/1k6/1B6 b - -
After 999 games at 1+0 on my QUAD
Mod vs Orig(94bb196) +168 =657 -174 -2 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Is a boolean option that when set allows Stockfish
to select the best book move across the possible ones.
Feature requested by Salvo Spitaleri.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Avoid incorrect mate scores in positions like
BK5/1R4b1/2k1Np2/3p3b/2p3pq/p1rB4/n2n1p2/8 w - -
Thanks for Jouni Uski for reporting the problem
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
