In this position we should have draw for repetition:
position fen rnbqkbnr/2pppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1 moves g1f3 g8f6 f3g1
go infinite
But latest patch broke it.
Actually we had two(!) very subtle bugs, the first is that Position::set()
clears the passed state and in particular 'previous' member, so
that on passing setupStates, 'previous' pointer was reset.
Second bug is even more subtle: SetupStates was based on std::vector
as container, but when vector grows, std::vector copies all its contents
to a new location invalidating all references to its entries. Because
all StateInfo records are linked by 'previous' pointer, this made pointers
go stale upon adding more element to setupStates. So revert to use a
std::deque that ensures references are preserved when pushing back new
elements.
No functional change.
Instead of creating a running std::thread and
returning, wait in Thread c'tor that the native
thread of execution goes to sleep in idle_loop().
In this way we can simplify how search is started,
because when main thread is idle we are sure also
all other threads will be idle, in any case, even
at thread creation and startup.
After lazy smp went in, we can simpify and rewrite
a lot of logic that is now no more needed. This is
hopefully the final big cleanup.
Tested for no regression at 5+0.1 with 3 threads:
LLR: 2.95 (-2.94,2.94) [-5.00,0.00]
Total: 17411 W: 3248 L: 3198 D: 10965
No functional change.
Use Position::square and Position::squares instead.
This allow us to remove king_square(), simplify
endgames and to have more naming uniformity.
Moreover, this is a prerequisite step in case
in the future we decide to retire piece lists
altoghter and use pop_lsb() to loop across
pieces and serialize the moves. In this way
we just need to change definition of Position::square
to something like:
template<PieceType Pt> inline
Square Position::square(Color c) const {
return lsb(byColorBB[c]);
}
No functional change.
Easier for tuning psq tables:
TUNE(myParameters, PSQT::init);
Also move PSQT code in a new *.cpp file, and retire the
old and hacky psqtab.h that required to be included only
once to work correctly, this is not idiomatic for a header
file.
Give wide visibility to psq tables (previously visible only
in position.cpp), this will easy the use of psq tables outside
Position, for instance in move ordering.
Finally trivial code style fixes of the latest patches.
Original patch of Lucas Braesch.
No functional change.
This micro-optimization only complicates the code and provides no benefit.
Removing it is even a speedup on my machine (i7-3770k, linux, gcc 4.9.1):
stat test master diff
mean 2,403,118 2,390,904 12,214
stdev 12,043 10,620 3,677
speedup 0.51%
P(speedup>0) 100.0%
No functional change.
Also remove useless StateCopySize64 optimization:
compiler uses SSE movups instruction anyhow and
does not need this trick (verified with fishbench).
No functional change.
Import C++11 branch from:
https://github.com/mcostalba/Stockfish/tree/c++11
The version imported is teh last one as of today:
6670e93e50
Branch is fully equivalent with master but syzygy
tablebases that are missing (but will be added with
next commit).
bench: 8080602
We really don't need to uglify in this way
our nice count() API with this ad-hoc hack.
So remove the hack and use the already
existing infrastructure.
No functional change.
Resolves#134
Adds support for Syzygy tablebases to Stockfish. See
the Readme for information on using the tablebases.
Tablebase support can be enabled/disabled at the Makefile
level as well, by setting syzygy=yes or syzygy=no.
Big/little endian are both supported.
No functional change (if Tablebases are not used).
Resolves#6
It is more idiomatic, we didn't used it
in the past because Position::pretty(Move)
had a calling argument, but now we can.
As an added benefit, we avoid a lot of string
copies in the process because now we avoid
std::ostringstream ss.
No functional change.
First, remove some dead code (function never called with a Move argument).
Then, remove printing of legal moves, which does not belong here. Let's keep commands orthogonal and minimal:
- the "d" command should display the board, nothing more, or less.
- "perft 1" will display the list of legal moves.
No functional change.
We avoid to use an ad-hoc table at the cost of a
relative_rank() call in advanced_pawn_push().
On my 32 bit system it is even slightly faster (on 64bit
may be different). This is the speed in nps alternating
old and new bench runs:
new
368890
368825
369972
old
367798
367635
368026
No functional change.
Instead of a passed pawn now we just require the pawn to
be in the opponent camp to be considered a dangerous
move. Added some renaming to reflect the change.
Passed both short TC test
LLR: 2.95 (-2.94,2.94) [-1.50,4.50]
Total: 10358 W: 2033 L: 1900 D: 6425
And long TC
LLR: 2.95 (-2.94,2.94) [0.00,6.00]
Total: 21459 W: 3486 L: 3286 D: 14687
bench: 8322172
