It seems totally unuseful because killers are not
used to order the moves in qsearch. Although there
is some functionality change, probably just a small
side effect.
After 5656 games on rc
Mod vs Orig: 1007 - 980 - 3669 ELO +1 (+- 3.7)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
So there is no need to explicitly check for king moves
when detecting prunable evasions.
Perhaps teoretically a very bit slower (I didn't test),
but it is more clear now what evasions we consider prunable.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Greatly cleanup SEE code and now it is also a bit
faster on gcc, about +0.6%.
Thanks to Mike Whiteley new SEE code that gave me
fresh ideas on how to cleanup this old stuff.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
A code semplification that could even be a slight increase,
anyhow is a reducing pruning patch, so it is good even
at equal strenght.
After 6342 games
Mod - Orig: 1040 - 974 - 4328 ELO +3 (+- 3.5)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Were removed when merged from Glaurung 2.2, but without
any test.
Note that weight has been increased from original 2 to 4 and
has been also fixed a bug where in the original version were
considered also diagonal sqaures for the rook, that are
contact squares but not checks.
After 4449 games at 30"+0.1
Mod - Orig: 717 - 649 - 3083 ELO +5 (+- 4.1)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Use the tail of moves[] array to store bad captures.
No functional change but some move reorder. Verified with old perft.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
And also other check bonuses.
After 4272 games on russian cluster at 30"+0.1
Mod - Orig: 711 - 612 - 2949 ELO +8 (+- 4.2)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
And rename in nodes now that we have only one.
After the beta-cut off counters removing we can
get rid also of this one.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
For now keep FutilityMarginsMatrix[] unchanged, in
future we are going to reduce to compensate for extra
margin.
At this moment it is enough we don't have regressions.
After 9694 games on russian cluster
Mod - Orig 1608 - 1578 - 6508 ELO +1 (+- 2.8)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Instead of one comparison in while() condition use two,
the first to check if the piece is exsistant and the second
to loop across pieces of that type.
This should help branch prediction in cases we have only
one piece of the same type, for instance for queens, the
first branch is always true and the second is almost always
false.
Increased speed of 0.3-0.5 % on Gcc pgo compiles.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Currently are used by evaluation itself and the
whole EvalInfo will be removed from global visibility
by next patch, so no reason to use them.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It will be more clear when we will go to add stuff
apart from king danger itself.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
First accumulate the bonus for each pawn, then call the
not very fast apply_weight().
Should be no functional change apart from rounding issues.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Set manually to zero the few fields that are
optionally populated and that's enough.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Avoid one address lookup in a very critical time path.
Unified also outpost bonus tables for knights and bishops.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Another 100 lines of dubious and ad-hoc code.
After 7644 games on russian cluster:
Mod - Orig 1285 - 1249 - 5110 ELO +1 (+- 3.2)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We don't need that !
We can infere from starting fen string if we are in
a Chess960 game or not. And note that this is a per-position
property, not an application wide one.
A nice trick is to use a custom manipulator (that is an
enum actually) to keep using the handy operator<<() on the
move when sending to std::cout, yes, I have indulged a
bit here ;-)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Plus a bunch of other minor optimizations.
With this power pack we have an increase
of a whopping 1.4% :-)
...and it took 3 good hours of profiling + hacking to get it out !
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
One hundred lines of code should be compensated by an
important ELO increase, otherwise are candidate for removal...
...and is not the case. We are well within error margin, so
remove the code even if we lose a couple of elo points, but
semplification is huge.
After 6494 games on russian cluster
Orig vs Mod 1145 - 1107 - 4242 (-2 ELO)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Where they belong.
Note that array PieceValueMidgame[] and PieceValueEndgame[]
are now declared extern in the header and moved in piece.cpp
so to avoid allocate the array each time the header is
included !
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
To avoid nasty bugs due to silently overriding of
common operator we enable the templates on a type
by type base using partial template specialization.
No functional change, zero overhead at runtime.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Note that in value we leave two specialized functions
to allow adding an integer, we don't want to add this
as a template becasue we want to control implicit
conversions to integer of an enum.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This is tricky because there are some special
binary fnctions with SquareDelta that we should
leave as they are.
Also note that we needed to add Unary minus template
to fix a comile error in SERIALIZE_MOVES_D macro that was
triggered because now we don't allow conversion to int.
No fuctional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Doing the conversion the compiler is now able to
spot two possible ambiguity calls that now we can
easily fix.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
When depth < DEPTH_ZERO we store with the same depth all
the positions, use -OnePly instead of -1 for consistency
with depth arithmetic.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
There is no reason to use a variable for this.
Also remove unused DEPTH_ZERO and DEPTH_MAX.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Regression test found the patches to be harmless,
so revert to keep code simpler.
Test1 at 20+0.1: (2500 - 3000) +0 ELO
Test2 at 1+0: (~1000) +2 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
There is a functional change because we now skip
more moves and because do_move() / undo_move() is
well known to be not reversible we end up with a
change in node count, although there is actually
no change but a bit speed up.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
To be uniform across the sources. As a nice side effect
I quickly spotted a couple of needed renames:
captured_piece() -> captured_piece_type()
st->capture -> st->capturedType
Proposed by Ralph and done with QtCreator
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
In root_search() we can compute depth at the beginning
once and for all.
Spotted by Ralph Stoesser.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We don't need to generate captures and non
captures in a separate step. This gives another
7% push to perft speed.
yes, I know, it is totally useless :-)
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We can now set member data as private because is no more
directly accessed.
Should be more clear now.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Move OptimumSearchTime, MaximumSearchTime and
ExtraSearchTime in TimeManager.
Note that we remove an useless initialization to 0 because
these variables are used only with time management.
Also introduce and use TimeManager::available_time()
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Firt step in unifying all time management under
a single umbrella. Just introduced the class without
even member data.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
After razoring, IID, null verification and singular
extension searches we have could have a dirty ss->bestMove,
restore to MOVE_NONE before to enter moves loop.
This should avoid to store in TT a stale move when
we fail low.
Tested together with previous patch that is the
one that gives ELO.
After 1152 games at 1+0 on my QUAD
Mod vs Orig +233 =716 -203 (+9 ELO)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
If singular extension search was succesful in the past then
skip another the SE search and extend of one ply.
Another way to mitigate the cost of SE at the price of
some more spurious extension, but on 90% of cases info
is correct.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Renamed in OptimumSearchTime and MaximumSearchTime,
should be more clear now.
Suggested by Joona.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Instead of ss->currentMove. It is more consistent and
clear to understand.
Remark by Ralph Stoesser.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
To compensate for the extra work skip singular
searches deemed to fail because excluded node
failed high already in the past.
After 1200 games at 1+0
Mod vs Orig +387 =1274 -339 (+8 ELO)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
The one in evaluate_passed_pawns() is just a micro
optimization, the other in evaluate_unstoppable_pawns()
is indeed a fix, although almost unmeasurable in real
games.
Bugs report and fixes by Marek Kwiatkowski
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Broken by recent patch. Also better document what's
happening there.
Verified to restore original behaviour.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Square and piece colors are two different things,
so use different types to avoid misunderstandings.
Suggested by Tord.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Less invasive then previous patches, but still a good
enhancement.
Also some indulge on STL algorithms :-)
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Complete rewrite the function and extend compatibility
also to X-FEN notation for Chess960.
We are now able to read standard FEN, Shredder-FEN and X-FEN.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Let be explicit about what this functions do, and
we save some code lines too.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
After we set ss->threatMove we could go under a IID step that
resets SearchStack ss and so also ss->threatMove.
When later we use that field in futility pruning we have this
set to MOVE_NONE !
The fix is to use a local variable and add threatMove to SplitPoint
to pass this move to slaves.
Spotted by Ralph Stoesser, fix suggested by Richard Vida.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Improvement is easily in error bar and there is
some added complexity making future changes more
difficult.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Because not all backward pawns are the same ;-) if the
blocking enemy pawn is near then our pawn is more backward
than another whose enemy pawn is far away so that can advance
for some sqaures.
After 2925 games at 30"+0 on my QUAD
Mod vs Orig +602 =1745 -578 +3 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
These functions have little to do with TranspositionTable
class and more with the search and in particular with the PV
handling. So move them where they belong.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
So to maximize the possibility to avoid to recalculate it
in the future. A small speed-up of 0.8%
Idea by Ralph Stoesser.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
The seocond check is no more needed now and
anyhow is wrong to overwrite a TT entry if
present.
Spotted by Ralph Stoesser.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It is more clear and also more correct because we
consider enemy pawns only in fornt of us and not just
on our file.
Very small functional change, almost not measurable, but
keep the patch for documenting purposes.
Spotted by Marek Kwiatkowski.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We don't need to pass side_to_move because we can get
it directly from the position object.
Note that in benchmark we always used to pass '0' and
it was a bug, but with no effect because was used only
in time[] and increment[], set always to 0 for both
colors.
Also additional small cleanup while there.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba