Integrate do_ep_move in undo_move() this reduces line count
and code readibility.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Integrate do_promotion_move() in do_move() this reduces line count
and code readibility.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Integrate do_ep_move in do_move() this reduces line count
and code readibility.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This fix a compile error under Linux with gcc when
there aren't the intel dev libraries.
Also simplify the previous patch moving TT definition
from search.cpp to tt.cpp so to avoid using passing a
pointer to TT to the current position.
Finally simplify do_move(), now we miss a prefetch in the
rare case of setting an en-passant square but code is
much cleaner and performance penalty is almost zero.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Move prefetching code inside do_move() so to allow a
very early prefetching and to put as many instructions
as possible between prefetching and following retrieve().
With this patch retrieve() times are cutted of another 25%
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
And put it in an already existing one so to
optimze a bit.
Also additional cleanups and code shuffles
all around the place.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Mostly of times we are interested only in the sign of SEE,
namely if a capture is negative or not.
If the capturing piece is smaller then the captured one we
already know SEE cannot be negative and this information
is enough most of the times. And of course it is much
faster to detect then a full SEE.
Note that in case see_sign() is negative then the returned
value is exactly the see() value, this is very important,
especially for ordering capturing moves.
With this patch the calls to the costly see() are reduced
of almost 30%.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Verification test give unusless result
After 999 games at 1+0
Mod vs Orig +250 =503 -246 50.20% +1 ELO
So we are well below our radar level. Neverthless
there are 100.000 games on Joona QUAD that we could
take in account and that shows that this tweak perhaps
has something good in it, altough very little.
Verification tests shows should not be a regression, at
least not a big one even in the worst case, so apply the
change anyway and keep the finger crossed ;-)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Avoid indirect calling of piece_of_color_and_type(c, PAWN) and its
alias pawns(c) in the pawn evaluation loop, but use the pawns
bitboards accessed only once before entering the loop.
Also explicitly mark functions as static to better self-document.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Instead of add and subtract pqst values corrisponding to
the move starting and destination squares, do it in one
go with the helper function pst_delta<>()
This simplifies the code and also better documents that what
we need is a delta value, not an absolute one.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
In Position we store a pointer to a StateInfo record
kept outside of the Position object.
When copying a position we copy also that pointer so
after the copy we have two Position objects pointing
to the same StateInfo record. This can be dangerous
so fix by copying also the StateInfo record inside
the new Position object and let the new st pointer
point to it. This completely detach the copied
Position from the original one.
Also rename setStartState() as saveState() and clean up
the API to state more clearly what the function does.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This is a very hot path function, profiling on Intel compiler
shows that inlining cuts in half the overhead.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It seems that these compilers do not like inline functions
that call a template when template definition is not in scope.
So move functions from header to in *.cpp file
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Rewritten hidden_checkers() to avoid calling
sliders attacks functions but just a much
faster squares_between()
Also a good code semplification.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Instead of copying all, copy only the fields that
are updated incrementally, not the ones that are
recalcuated form scratch anyway.
This reduces copy overhead of 30%.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It is slower the previous uglier but faster code.
So completely restore old one for now :-(
Just leave in the rework of status backup/restore in do_move().
We will cherry pick bits of previous work once we are sure
we have fixed the performance regression.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This let us to calculate only pinners when we now that
dc candidates are not possible.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
In do_move() use previous pinned bitboards values to compute
the new one after the move. In particulary we end up with the
same bitboards in most cases. So detect these cases and just
keep the old values.
This should speedup a lot this slow computation in a very hot
path so that we can use this important info everywhere in the
code at very cheap cost.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
There was one occurence when the StateInfo variable went
out of scope before the corresponding Position object.
This yelds to a crash. Bug was not hit before because occurs
only when using an UCI interface and not the usual benchmark.
The fix consists in copying internally the content of the
about to stale StateInfo.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Instead of copy the old state in the new one, copy only
fields that will be updated incrementally, not the ones
that will be recalculcated anyway.
This let us copy 13 bytes instead of 28 for each do_move()
call.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Probably is slightly slow, but code is surely better
in this way. We will optimize later for speed.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We don't backup anymore but use the renamed StateInfo
argument passed in do_move() to store the new position
state when doing a move.
Backup is now just revert to previous StateInfo that we know
because we store a pointer to it.
Note that now backing store is up to the caller, Position is
stateless in that regard, state is accessed through a pointer.
This patch will let us remove all the backup/restore copying,
just a pointer switch is now necessary.
Note that do_null_move() still uses StateInfo as backup.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We store it now in the same UndoInfo struct as 'previous'
field, so when doing a move we also know where to get
the previous info when undoing the back the move.
This is needed for future patches and is a nice cleanup anyway.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Also templetize compute_value() can be simpler now that
the above is templetized too.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This nice union trick let us optimize the speed and
remove the now unuseful backup() and restore() functions.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
After have been calculated cache their values
so to avoid another expensive call to hidden_checks()
if pinned_pieces() or discovered_check_candidates() are
called with the same position.
Add also interface to get pinners bitboard, we already have
this value so save it instead of discard.
Now that, after the first call to pinned_pieces() the following
are very cheap we can rewrite and cleanup all the checking handling.
So this patch is a prerequisite for future work.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
They hide the underlying uniform function call with
no benefit.
A little bit more verbose but now is clear what happens.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
In this case firstlocates the least valuable attacker, if any,
then proceed as usual.
This will be used by next patch.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Teach Position::print() to optionally print a
given move in san notation in addition to
the ASCII representation of the board.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
