We just need to verify if a legal move is among the
SearchMoves, so we don't need a vector for this.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It could lead to terrible mistakes otherwise, as
it happened during a game on playchess when on
this position (after white's f4):
2q4r/4b1k1/p3rpp1/3np2p/PpNpNP1P/1P1P2PQ/2P1R3/4R1K1 b - - 0 1
SF moves immediately e5xf4 instead of the correct f5.
In general during engine matches it is impossible the
opponent leaves a piece hanging or anyhow starts a
clear losing sequence. So avoid to fall in subtle traps.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Further increase safety against time losses. After this
change (tested on LittleBlitzer and cutechess) I had no
more time losses at 2" and 1"+0.02 TC both on Windows
and Linux on more than 10000 games.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We try hard not to lose on time even under extreme
time pressure. We achieve this through 3 different but
coordinated steps:
1) Increase max frequency of timer events
2) Quickly return after a stop signal
3) Take in account timer resolution
With these SF played under LittleBlitzer at 1"+0.02 and 3"+0
without losing on time even one game.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
The aim is to have shorter names without losing
readibility but, if possible, increasing it.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Retire open(), close() and name() from public visibility
and greately simplify the code. It is amazing how much
can be squeezed out of an already mature code !
No functional change
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Greatly improves the usage. User defined conversions
are a novelity for SF, another amazing C++ facility
at work !
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
The condition for a mate score was wrong:
abs(v) < VALUE_MATE - PLY_MAX * ONE_PLY
instead of
abs(v) < VALUE_MATE_IN_PLY_MAX
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
During the search we score a mate as "plies to mate
from the root" to compare in an homogeneous way the
values returned by different sub-trees. However we
store in TT a mate score as "plies to mate from the
current position" the let the TT value remain valid
across the game.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It is simple but somewhat tricky code that deserves
a bit of documentation. A bit of renaming while there.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Add the check that alpha < beta - 1 if and only if PvNode is true.
The current code would not flag PvNode and alpha == beta - 1. In
other words, the || is not an exclusive OR!.
Also sync assert conditions of search() and qsearch()
Suggested by Rein Halbersma.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Make a better use of C++ operators overloading to
streamline the APIs.
Also sync polyglot.ini file while there.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Follow the suggested Qt style:
http://doc.qt.nokia.com/qq/qq13-apis.html
It seems to me simpler and easier to read.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
I am not able to reproduce the speed regression anymore,
and also we were using cout even before speed regression
so probably the reason is not there.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We don't use killers to order evasions, so it
seems natural do not consider an evasion cut-off
move as a possible killer. Test shows almost no
change, as it should be becuase this is a really
tiny change, but neverthless seems the correct
thing to do.
After 11893 games
Mod vs Orig 1773 - 1696 - 8424 ELO +2 (+-3.4)
Idea from Critter.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Take advantage of argument-dependent lookup (ADL) to
avoid specifying std:: qualifier in some STL functions.
When a function argument refers to a namespace (in this
case std) then the compiler will search the unqualified
function in that namespace too.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Seems sensibly faster: On a
./stockfish bench > /dev/null
We have +2% on mingw and even +5% on MSVC !
Also removed the nice but complex enum set960 machinery,
use directly the underlying move_to_uci() function.
Speed regression reported by Heinz van Saanen.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Do not return the book move if is not among the
RootMoves,in particular if we have been asked to
search on a move subset with "searchmoves" then
return book move only if it is among this subset.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Introduce pv_info_to_log() and pv_info_to_uci() and
greatly cleanup this stuff.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Actually after last patch it happens that delta
starts always with the fixed value of 16.
So further remove useless code.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It seems that we just need to look at previous score to
compute aspiration window size.
After 5350 games:
Mod vs Orig 800 - 803 - 3647 ELO +0 (+- 5.2)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Diretcly use the underlying std::vector<Move> and the
STL algorithms. Also a bit of cleanup while there.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Comments should be informative but not pedantic / obvious.
The only exception is the function description where we
indulge a bit on the "chatty" side, but has always been like
this since Glaurung times, so we continue with this tradition.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Tested togheter with previous patch; shows no regression and
is a semplification.
After 5817 games:
Mod vs Orig 939 - 892 - 3986 ELO +2 (+- 5.1)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
A cast rarely is the right solution. In this case was enough
to redifine 3 variables with type size_t instead of int
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It seems we don't have any added value. Note that the
moves that were used to be extended are still flagged
as dangerous so to avoid at least pruning them.
After 9555 games
Mod vs Orig 1562 - 1540 - 6453 ELO +0 (+- 4)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
As Heinz says:
"Function empty() should have a constant run-time even
on lousy compilers and you spare the not.
The change is even measurable: + 100-150 nodes/sec. Wow:-)"
Patch from Heinz van Saanen
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Detach from the UI thread the input arguments used by
the search threads so that the UI thread is able to receive
and process any command sent by the GUI while other threads
keep searching.
With this patch there is no more need to block the UI
thread after a "stop", so it is a more reliable and
robust solution than the previous patch.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Fixes an hang when playing with ponder ON. Perhaps there is still
a very small race but now it seems engine does not hang anymore.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Move global search-related variables under "Search" namespace.
As a side effect we can move uci_async_command() and
wait_for_stop_or_ponderhit() away from search.cpp
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Use the starting thread to wait for GUI input and instead use
the other threads to search. The consequence is that now think()
is alwasy started on a differnt thread than the caller that
returns immediately waiting for input. This reformat greatly
simplifies the code and is more in line with the common way
to implement this feature.
As a side effect now we don't need anymore Makefile tricks
with sleep() to allow profile builds.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
If we are pondering we will stop the search only when
GUI sends "ponderhit" or "stop" commands or when we reach
maximum depth. In all the other cases we continue to search
so there is no need to verify for available time.
Also better clarify why wait_for_stop_or_ponderhit() before
to exit in some cases.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
