It is more clear and should be a bit faster too.
Reverted also previous optimization patch because
seems do not increase actual speed.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Almost no change, but it is in sync with what we do in search
and in any case the ELO difference is very small (because the
events when the intermediate research triggers are very rare),
too small to be measured, we just verify we don't have any
unexpected regressions.
After 802 games at 1+0 full QUAD
Mod vs Orig +114 =581 -107 +3 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
If we have pruned one capture due to its final value
we can prune also following ones because captures are
MVV ordered.
Also avoid a compare when not in PV because in that
case is always false.
No functional change.
Get it from the position instead.
A good semplification of function calling and a speedup too.
No functional change also with faked split.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This is the best place because when we split we do a
copy of the position and also threadID, once set in a
given position, never changes anymore.
Forbid use of Position's default and copy c'tor to avoid
nasty bugs in case a position is created without explicitly
setting the threadID.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Do it once at the beginning becuase they are always reset
after use in the calling place where are set.
No functional change also with faked split.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Also renamed allowNullmove in skipNullMove to reverse
the logic so that the field is initialized to 0 (false)
instead of 1 (true).
No functional change also with faked split.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
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>
And remove from main do_move() flow. Just a small speedup
because we avoid two branches in the common case.
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>
The index at 0 was reserved for no-pieces
information. But we don't need that.
This is a prerequisite for next patch.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
They are both 64 bits unsigned integer, but it
is correct to use the proper type.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
After 999 games at 1+0
Mod vs Orig +148 =712 -139 +3 ELO
The added complexity doesn't seems to pay off and could
even scale worst with longer TC. So revert.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
The tested square comes from a bitboard anded with
pos.pieces_of_color(Us), so assert is useless.
Another nitpick report by Marek Kwiatkowski ;-)
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
One of the most nitpicking patches I have ever seen.
Of course almost no functional change, but added just
becasue we are very pedantic ;-)
Spotted by Marek Kwiatkowski
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It was erroneusly reversed. Bug from Glaurung times.
Probably a full re-tuning is needed anyhow.
Spotted and fixed by Ralph Stoesser.
After 999 games almost no change, but modified anyway
for documentation reasons.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Increase threats score according to the number of
threats and to the side to move.
Constants have been balanced after ~34k iterations.
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>
When compiling with MSVC we don't use the Makefile
so tweak a bit the Makefile to allow to let prefetch
in by default so that it works under Windows.
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>
We already tested few lines before with:
assert(pos.pawn_is_passed(Us, s));
Spotted by Marek Kwiatkowski.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Does not help and it slows downs a bit because it
is not cheap to get the possible discovered checks
out of a position.
After 997 games at 1+0
Mod vs orig +153 =692 -152 +0 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
There is no reason for that since tr cannot become negative.
Spotted by Ralph Stoesser.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Final values for threath tuning (after ~30k iterations)
Verified to be equivalent with tuning branch.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This is a more standard naming (see chessprogramming wiki)
and is more stick to what table is and not what is used for.
Code in pawns.cpp is a bit more readable now, at least for me ;-)
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Avoid a double bitcount in test for candidate passed
pawn when we don't have any supporting pawn.
Also use outpost_mask() instead of build it up on
the fly.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Pass the color for which the square is to be
considered weak, not the opposite.
It is more natural and intuitive in this way.
No functional change.
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>
It was broken on Windows 64bit with MSVC and possibly
on other platforms, so revert to old proven one.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Remove a lot of complex, obscure and useless code.
After 999 games at 1+0
Mod vs Orig +162 =673 -164 -1 ELO
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>
A bigger "safety" value is actually a bigger
threat for the king, so it is a bigger "danger"
With this renaming "Cowardice" and "Aggressiveness"
UCI parameters become easier to understand.
It is also easier to understand why the once "safety"
value (that is a "danger") is subtracted from evaluation
instead of being added.
No functional change.
Use a Weights[] array instead of named variables to
store evaluation weights.
No functional 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>
The idea here is that if we cut-off after a stand pat the
already exsisting TT entry was not usable with current
beta, so overwrite anyway.
After 999 games at 1+0
Mod vs Orig +173 =665 -161 + 4 ELO
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>
In this case we avoid to name the 'black' version of the
endgame function but use a vector indexed by color instead.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Because exit_threads() references the global object TM, we
need to call the function when still inside main(), otherwise,
due to undefined global object initialization and destruction
we could end up with referencing an already destroyed object.
Actually this should not happen because Application singleton
is initialized _only_ after all the other globals due to how
Application::initialize() is defined, but this is very tricky
C++ and not easy to follow, even for me ;-)
Also rearranged a bit main() code flow.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Moved evaluation of unstoppable pawns out of
evauation of passed pawns because event frequency is
much lower. Added evaluate_unstoppable_pawns() that
is called very seldom and contains all the unstoppable
pawn logic.
No functional change.
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>
Also fix dimension of UnpairedPawnsTable[] to accomodate the
case in which we have 8 unpaired pawns, i.e. only one side has
pawns, the other side has no pawns.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
The idea is to reduce the score if we have many
pawns opposing an enemy pawn so that the draw
possibility increases.
Just introduced the logic, but no functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
A pawn is candidate to be passed if doesn't have enemy pawns
in just front of him, not also behind !
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba