Stockfish Development Versions are build automatically if there are changes on the master branch in the git repository (https://github.com/official-stockfish/Stockfish). Use it at your own risk.
They are compiled with gcc 5.4.0/mingw 5.3.1 on Ubuntu 16.04.
2.Jan.2016: BMI build now slightly faster due to profiling.
Development builds for macOS are available at stockfishchess.de
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!! latest version !!


Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Marco Costalba
Date: Mon Aug 14 23:01:58 2017 -0700
Timestamp: 1502776918

Fix incorrect StateInfo

We use Position::set() to set root position across
threads. But there are some StateInfo fields (previous,
pliesFromNull, capturedPiece) that cannot be deduced
from a fen string, so set() clears them and to not lose
the info we need to backup and later restore setupStates->back().
Note that setupStates is shared by threads but is accessed
in read-only mode.

This fixes regression introduced by df6cb446eaf21

Tested with 3 threads at STC:
LLR: 2.95 (-2.94,2.94) [-4.00,0.00]
Total: 14436 W: 2304 L: 2196 D: 9936

Bench: 5608839
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Marco Costalba
Date: Sun Aug 13 05:46:21 2017 -0700
Timestamp: 1502628381

Run clang-tidy 'modernize'

Some warnings after a run of:

$ clang-tidy-3.8 -checks='modernize-*' *.cpp syzygy/*.cpp -header-filter=.* -- -std=c++11

I have not fixed all suggestions, for instance I still prefer
to declare the type instead of a spread use of 'auto'. I also
perfer good old 'typedef' to the new 'using' form.

I have not fixed some warnings in the last functions of
syzygy code because those are still the original functions
and need to be completely rewritten anyhow.

Thanks to erbsenzaehler for the original idea.

No functional change.
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Marco Costalba
Date: Sun Aug 13 04:41:59 2017 -0700
Timestamp: 1502624519

Thread code reformat

Simplify out low level sync stuff (mutex
and friends) and avoid to use them directly
in many functions.

Also some renaming and better comment while
there.

No functional change.
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: tthsqe12
Date: Sat Aug 12 02:47:11 2017 -0700
Timestamp: 1502531231

Fix the handling of opposite bishops in KXK endgame evaluation

The case of three or more bishops against a long king must look at all of the
bishops and not just the first two in the piece lists. This patch makes sure
that the position is treated as a win when there are bishops on opposite
colors. This functional change is very small because bench remains the same.

LLR: 2.95 (-2.94,2.94) [-4.00,0.00]
Total: 24249 W: 4349 L: 4275 D: 15625
http://tests.stockfishchess.org/tests/view/598186530ebc5916ff64a218

Bench: 5608839
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Joost VandeVondele
Date: Thu Aug 10 22:42:52 2017 -0700
Timestamp: 1502430172

Simplify finished search in ponder/infinite mode.

In this rare case (e.g. go infinite on a stalemate),
just spin till ponderhit/stop comes.

The Thread::wait() is a renmant of the old YBWC
code, today with lazy SMP, threads don't need to
wait when outside of their idle loop.

No functional change.
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Marco Costalba
Date: Thu Aug 10 12:47:31 2017 -0700
Timestamp: 1502394451

Re-apply the fix for Limits::ponder race

But this time correctly set Threads.ponder

We avoid using 'limits' for passing pondering
flag because we don't want to have 2 ponder
variables in search scope: Search::Limits.ponder
and Threads.ponder. This would be confusing also
because limits.ponder is set at the beginning of
the search and never changes, instead Threads.ponder
can change value asynchronously during search.

No functional change.
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Marco Costalba
Date: Thu Aug 10 10:59:38 2017 -0700
Timestamp: 1502387978

Revert "Fix a race on Limits::ponder"

This reverts commit 5410424e3d036b43715c7989aa99e449cdcde18e.

After the commit pondering is broken, so revert for now. I will
resubmit with a proper fix.

The issue is mine, Joost original code is correct.

No functional change.
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Joost VandeVondele
Date: Thu Aug 10 10:46:46 2017 -0700
Timestamp: 1502387206

Fix a race on Limits::ponder

Limits::ponder was used as a signal between uci and search threads,
but is not an atomic variable, leading to the following race as
flagged by a sanitized binary.

Expect input:
```
spawn ./stockfish
send "uci\n"
expect "uciok"
send "setoption name Ponder value true\n"
send "go wtime 4000 btime 4000\n"
expect "bestmove"
send "position startpos e2e4 d7d5\n"
send "go wtime 4000 btime 4000 ponder\n"
sleep 0.01
send "ponderhit\n"
expect "bestmove"
send "quit\n"
expect eof
```

Race:
```
WARNING: ThreadSanitizer: data race (pid=7191)
Read of size 4 at 0x0000005c2260 by thread T1:

Previous write of size 4 at 0x0000005c2260 by main thread:

Location is global 'Search::Limits' of size 88 at 0x0000005c2220 (stockfish+0x0000005c2260)
```

The reason of teh race is that ponder is not just set in UCI go()
assignment but also is signaled by an async ponderhit in uci.cpp:

else if (token == "ponderhit")
Search::Limits.ponder = 0; // Switch to normal search

The fix is to add an atomic bool to the threads structure to
signal the ponder status, letting Search::Limits to reflect just
what was passed to 'go'.

No functional change.
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Marco Costalba
Date: Thu Aug 10 10:19:56 2017 -0700
Timestamp: 1502385596

Fix some races and clarify the code

Better split code that should be run at
startup from code run at ucinewgame. Also
fix several races when 'bench', 'perft' and
'ucinewgame' are sent just after 'bestomve'
from the engine threads are still running.

Also use a specific UI thread instead of
main thread when setting up the Position
object used by UI uci loop. This fixes a
race when sending 'eval' command while searching.

We accept a race on 'setoption' to allow the
GUI to change an option while engine is searching
withouth stalling the pipe. Note that changing an
option while searchingg is anyhow not mandated by
UCI protocol.

No functional change.
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: AndyGrant
Date: Thu Aug 10 10:04:30 2017 -0700
Timestamp: 1502384670

Make variable naming consistent

moved_piece is the only variable in search not using camel case
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Joost VandeVondele
Date: Thu Aug 10 02:06:21 2017 -0700
Timestamp: 1502355981

Unify scoring functions in MovePicker

No functional change.
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Joost VandeVondele
Date: Sun Aug 6 01:45:54 2017 -0700
Timestamp: 1502009154

Remove Stack/thread dependence in movepick

as a lower level routine, movepicker should not depend on the
search stack or the thread class, removing a circular dependency.
Instead of copying the search stack into the movepicker object,
as well as accessing the thread class for one of the histories,
pass the required fields explicitly to the constructor (removing
the need for thread.h and implicitly search.h in movepick.cpp).
The signature is thus longer, but more explicit:

Also some renaming of histories structures while there.

passed STC [-3,1], suggesting a small elo impact:

LLR: 3.13 (-2.94,2.94) [-3.00,1.00]
Total: 381053 W: 68071 L: 68551 D: 244431
elo = -0.438 +- 0.660 LOS: 9.7%

No functional change.
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: snicolet
Date: Tue Aug 1 18:41:29 2017 -0700
Timestamp: 1501638089

Tweak connected pawns seed[] array values

Raise a little bit the values in the connected pawns seed[] array.

STC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 99033 W: 17939 L: 17448 D: 63646
http://tests.stockfishchess.org/tests/view/597355630ebc5916ff649e3e

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 48044 W: 6371 L: 6099 D: 35574
http://tests.stockfishchess.org/tests/view/597596610ebc5916ff649eba

Bench: 5608839

Closes #1182
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Rocky640
Date: Tue Aug 1 18:37:54 2017 -0700
Timestamp: 1501637874

Rework the "unsupported" penalty into a "supported" bonus

A pawn (according to all the searched positions of a bench run) is not supported 85% of the time,
(in current master it is either isolated, backward or "unsupported").

So it made sense to try moving the S(17, 8) "unsupported" penalty value into the base pawn value hoping for a more representative pawn value, and accordingly
a) adjust backward and isolated so that they stay more or less the same as master
b) increase the mg connected bonus in the supported case by S(17, 0) and let the Connected formula find a suitable eg value according to rank.

Tested as a simplification SPRT(-3, 1)

Passed STC
http://tests.stockfishchess.org/tests/view/5970dbd30ebc5916ff649dd6
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 19613 W: 3663 L: 3540 D: 12410

Passed LTC
http://tests.stockfishchess.org/tests/view/597137780ebc5916ff649de3
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 24721 W: 3306 L: 3191 D: 18224

Bench: 5581946

Closes #1179
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: VoyagerOne
Date: Thu Jul 27 02:14:18 2017 -0700
Timestamp: 1501146858

Remove redundant if-statements

No functional change

Closes #1173
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: mstembera
Date: Sun Jul 23 17:35:44 2017 -0700
Timestamp: 1500856544

Tuned PSQT using a custom tuner.

bench: 5878420

Closes #1177
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: VoyagerOne
Date: Sun Jul 23 17:25:23 2017 -0700
Timestamp: 1500855923

Simplify aspiration window

Don't modify alpha window on fail-high

Bench: 5875983

Closes #1172
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Joost VandeVondele
Date: Sun Jul 23 17:23:14 2017 -0700
Timestamp: 1500855794

Faster travis checks

in the last month a couple of timeouts have been seen in travis valgrind testing, leading to undesired false positives. The precise cause of this is unclear: a normal valgrind instrumented run is about 6min, the timeout is 10min. Either there are rare hangs (not reproduced locally), or maybe the actual runtime fluctuates on the travis infrastructure (which uses VMs on AWS as far as I know). This patch leads to roughly a 2x speedup of the instrumented testing by reducing the depth from 10 to 9. If timeouts persist, it needs further analysis.

No functional change.

Closes #1171
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Marco Costalba
Date: Sat Jul 15 07:28:38 2017 +0200
Timestamp: 1500096518

Move game_phase() to material.cpp

For some reason, although game phase is used
only in material, it is computed in Position.

Move computation to material, where it belongs,
and remove the useless call chain.

No functional change.
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Joona Kiiski
Date: Thu Jul 13 16:36:27 2017 -0700
Timestamp: 1499988987

Revert "Remove questionable gcc flags from profile-build"

This reverts commit 0371a8f8c4a043cb3e7d08b5b8e7d08d49f28324.
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: joergoster
Date: Thu Jul 13 16:30:03 2017 -0700
Timestamp: 1499988603

Provide selective search depth info for each pv move

No functional change

Closes #1166
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Joost VandeVondele
Date: Thu Jul 13 16:08:37 2017 -0700
Timestamp: 1499987317

Move stop signal to Threads

Instead of having Signals in the search namespace,
make the stop variables part of the Threads structure.
This moves more of the shared (atomic) variables towards
the thread-related structures, making their role more clear.

No functional change

Closes #1149
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Joona Kiiski
Date: Sat Jul 8 14:20:46 2017 -0700
Timestamp: 1499548846

Remove questionable gcc flags from profile-build

Optimization options for official stockfish should be
consistent, easy, future proof and simple.

We don't want to optimize for any specific version of gcc

No functional change

Closes #1165
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: GuardianRM
Date: Sat Jul 8 14:14:14 2017 -0700
Timestamp: 1499548454

Queen vs. Minors imbalance

Addition of correction values in case of Imbalance of queens,
depending on the number of light pieces on the side without a queen.

Passed patch:

STC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 29036 W: 5379 L: 5130 D: 18527

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 13680 W: 1836 L: 1674 D: 10170

Bench: 6258930

Closes #1155
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Windows 32
Linux x64 for Haswell CPUs
Linux x64 for modern computers
Linux x64
Author: Marco Costalba
Date: Sun Jul 2 22:06:47 2017 -0700
Timestamp: 1499058407

Don't uselessy share rootDepth

It is not needed becuase the only case is a real special
one (bench on depth with many threads) and can be easily
rewritten to avoid sharing rootDepth.

Verified with ThreadSanitizer.

No functional change.

Closes #1159

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