Simplify Endgames::probe()

With this API change we simplify both function and caller site.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Fix bench with fen files regression

Erroneusly adds default positions to the fens
loaded from external file.

Bug introduced in adb71b8096436a

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Merge remote-tracking branch 'upstream/master'
Micro-optimize last_1() for 32bits

Verified assembly it is a bit simpler.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Big Position renaming

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Use a Thread instead of an array index

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Rewrite pop_1st_bit() to be endian independent

With this change sources are fully endianess
independent, so we can simplify the Makefile.

Somewhat surprisingly we don't have any speed
regression !

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Introduce thread local storage

Use thread local storage to store a pointer to the thread we
are running on. This will allow to remove thread info from
Position class.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Don't store Thread info in Position

But use the newly introduced local storage
for this. A good code semplification and also
the correct way to go.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Teach UI thread to use main thread resources

So to avoid a crash when setting the moves in
UCI "position startpos moves ...." command.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Fix a (theoretical) race leading to a crash

After we release the SplitPoint lock the master, suppose
is main thread, can safely return and if a "quit" command
is pending, main thread exits and associated Thread object
is freed. So when we access master->is_searching a crash
occurs.

I have never found such a race that is of course very rare
becuase assumes that from lock releasing we go to sleep for
a time long enough for the main thread to end the search and
return. But you can never know, and anyhow a race is a race.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Use thread_local compiler specifics

Much faster then pthread_getspecific() but still a
speed regression against the original code.

Following are the nps on a bench:

Position
454165
454838
455433

tls
441046
442767
442767

ms (Win)
450521
447510
451105

ms (pthread)
422115
422115
424276

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Revert thread_local stuff

Unfortunatly accessing thread local variable
is much slower than object data (see previous
patch log msg), so we have to revert to old code
to avoid speed regression.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Replace Position::copy()

With assignment operator. And fix Position::flip().

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Revert "Penalty for undefended rook"

After extensive test Gary says:

"So, after 16k games at 10"+1" on an i7, the undefended rook test
looks to be not good (albeit by a very small margin).
3063 - 3093 - 9844 (-1).

I doubt that is causing the regression, but even so, it looks like
it's not worth keeping, and we can go back to the simpler undefended
minors check."

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Don't need to wait after a "ponderhit"

It is enough to wake up main thread. This is
a better fix than d033d5e06a604f.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Teach 'bench' to run current position

Now that we can call bench from command prompt
has a sense to teach bench to run the current
set position. To do this is enough to call bench
with 'current' as fen source parameter.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Use bench to implement UI 'perft' command

Now that we can call bench on current position
we can directly use it to perform our perft.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Fix 'bench' for Chess960 case

Now a fen file with Chess960 positions is
correctly parsed. But it is mandatory to set
"UCI_Chess960" option _before_ to call bench.

Note that this was not needed/possible before
adding the possibility to call 'bench' from
command prompt.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Reduce stack usage

Shrink dimensions of the biggest stack consumers arrays.
In particular movesSearched[] can be safely shrinked
without any impact on strenght or risk of crashing.
Also MAX_PLY can be reverted to 100 with almost no impact
so to limit search recursion and hence stack allocation.

A different case is for MAX_MOVES (used by Movepicker's
moves[]), because we know that do exsist some artificial
position with about 220 legal moves, so in those cases SF
will crash. Anyhow these cases are never found in games.
An open risk remains perft, especially run above handcrafted
positions.

This patch originates from a report by Daylen that found
SF crashing on his Mac OS X 10.7.3 while in deep analysys
on the following position:

8/3Q1pk1/5p2/4r3/5K2/8/8/8 w - - 0 1

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>