The trick is to classify more position at first cycle,
so to reduce following work. Speed up is of about 50% !
Also some cleanup while there.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Seems there is no regression so prefer to prune less.
After 8278 games
Mod vs Orig 1246 - 1265 - 5767 +0 ELO (+- 4.2)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We should start from i = 0, it works by accident because
static storage BSFTable[] is init to zero by default.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
In case we have more than one promotion move, prefer
the one that captures the biggest piece.
Almost no functional change, anyhow I don't expect any
ELO change, it is just the correct thing to do.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It seems much worst in number of nodes seacrhed to reach
the depth and anyhow does not give any advantage to the
Onno's oroginal one.
So revert by now and perhaps readd when we find something
clearly better.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Allow to choose among 4096 instances of pseudo-random
sequences instead of the previous 64 so the probability
to find a better sequence increases and actually we have
a much better 64 bit case and we can also use the 64 bit
version of pick_magic() also for 32 bits and althoug sub
optimal, because now we can have more choices results are
even slightly better also for 32 bit.
Use also a faster submask().
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
After 12613 games at 20"+0.1 on QUAD
Mod vs Orig 1870 - 1863 - 8880 ELO +0 (+- 3.3)
So no performance change but it is a code semplification
and also is more easy to understand.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Good result for 32 bit case where computation is very fast,
still not satisfying on 64 bit case where the magics seem
a bit harder to get.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Due to a -2% speed penalty. This patch takes the best
of the previous series without the regression due to
introduction of Magic struct.
Speedup against previous revision is of almost 3% !!!!
No functional change both in 32 and 64 bits.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We can calculate them counting the masks bits.
Also small tweak to sliding_attacks()
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Here the idea is to test probcut not only after bad
captures, but after any bad move, i.e. any move that
leaves the opponent with a good capture.
Ported by a patch from Onno, the difference from
original version is that we have moved probcut after
null search.
After 7917 games 4 threads 20"+0.1
Mod vs Orig: 1261 - 1095 - 5561 ELO +7 (+- 4.2) LOS 96%
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We really want PV moves and also Split Point moves to be
legal to avoid messing the move counter and corresonding
PV move detection or shared Split Point's counter variable.
This fixes a real bug where a position with only one move
allowed returns bestValue == -VALUE_INFINITE if the move
turns out to be illegal.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We disjoint pseudo legal detection from full legal detection.
It will be used by future patches.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
When we are in check and we move the king then testing with
pl_move_is_legal(m, pinned) is not enough becuase we cannot
rely on attackers_to() but we have to explicitly remove the
king form the occupied bitboard to catch as invalid moves like
b1a1 when opposite queen is on c1.
Our move generator already produces correct evasions so we
just need to add the extra verification to move_is_legal().
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Found another missed control in move_is_legal() thanks to
brute force testing.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Add a new check in move_is_legal()
Avoid useless casting in move.h while there.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It is interesting the fact that we need to test for
move_is_castle(m) anyway and not relying on testing
if destination square is attacked. Indeed the latter
condition fails if the castling rook is attacked,
castling is coded as "king captures the rook" but it
is legal in that case.
Verified no functional change with beginning of the series.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
