stockfish
21 months agoQS Pruning Simplification
VoyagerOne [Sun, 30 Aug 2020 01:13:05 +0000 (21:13 -0400)]
QS Pruning Simplification

Remove depth dependence in QS pruning

STC:
LLR: 2.95 (-2.94,2.94) {-1.25,0.25}
Total: 40536 W: 4442 L: 4358 D: 31736
Ptnml(0-2): 209, 3330, 13118, 3390, 221
https://tests.stockfishchess.org/tests/view/5f49035b3def6407861152f9

LTC:
LLR: 2.95 (-2.94,2.94) {-0.75,0.25}
Total: 97104 W: 5164 L: 5130 D: 86810
Ptnml(0-2): 103, 4478, 39377, 4470, 124
https://tests.stockfishchess.org/tests/view/5f4939d53def640786115322

closes https://github.com/official-stockfish/Stockfish/pull/3077

Bench: 3865238

21 months agoAdd / remove leaves from search tree ttPv
MJZ1977 [Fri, 28 Aug 2020 10:06:36 +0000 (12:06 +0200)]
Add / remove leaves from search tree ttPv

add if previous leaf is in search tree and we didn't find a counter move
else remove the position if the leaf is the last one in search tree.

STC : https://tests.stockfishchess.org/tests/view/5f49203c3def640786115314
LLR: 2.95 (-2.94,2.94) {-0.25,1.25}
Total: 29968 W: 3381 L: 3195 D: 23392
Ptnml(0-2): 146, 2432, 9671, 2560, 175

LTC : https://tests.stockfishchess.org/tests/view/5f494bea3def640786115336
LLR: 2.96 (-2.94,2.94) {0.25,1.25}
Total: 84952 W: 4619 L: 4333 D: 76000
Ptnml(0-2): 86, 3765, 34481, 4065, 79

closes https://github.com/official-stockfish/Stockfish/pull/3075

Bench 3527337

21 months agoReintroduce depth reduction
Unai Corzo [Fri, 28 Aug 2020 07:27:15 +0000 (09:27 +0200)]
Reintroduce depth reduction

Reintroduce depth reduction if the position is not in TT.

STC https://tests.stockfishchess.org/tests/view/5f4652e85089a564a10d868c
LLR: 2.97 (-2.94,2.94) {-0.25,1.25}
Total: 40240 W: 4535 L: 4331 D: 31374
Ptnml(0-2): 215, 3276, 12969, 3410, 250

LTC https://tests.stockfishchess.org/tests/view/5f46ca5e5089a564a10d86f3
LLR: 2.93 (-2.94,2.94) {0.25,1.25}
Total: 63096 W: 3426 L: 3188 D: 56482
Ptnml(0-2): 51, 2798, 25645, 2970, 84

closes https://github.com/official-stockfish/Stockfish/pull/3072

bench: 3611906

21 months agoCleaner make help
Joost VandeVondele [Wed, 26 Aug 2020 16:00:54 +0000 (18:00 +0200)]
Cleaner make help

do not print details if ARCH is an empty string. Follow up for b0b4ca17db49ed03057b5fa4ee4a12dab0e9c9e6

https://github.com/official-stockfish/Stockfish/pull/3071

No functional change

21 months agoEmbed default net, and simplify using non-default nets
Stéphane Nicolet [Sun, 23 Aug 2020 11:43:38 +0000 (13:43 +0200)]
Embed default net, and simplify using non-default nets

covers the most important cases from the user perspective:

It embeds the default net in the binary, so a download of that binary will result
in a working engine with the default net. The engine will be functional in the default mode
without any additional user action.

It allows non-default nets to be used, which will be looked for in up to
three directories (working directory, location of the binary, and optionally a specific default directory).
This mechanism is also kept for those developers that use MSVC,
the one compiler that doesn't have an easy mechanism for embedding data.

It is possible to disable embedding, and instead specify a specific directory, e.g. linux distros might want to use
CXXFLAGS="-DNNUE_EMBEDDING_OFF -DDEFAULT_NNUE_DIRECTORY=/usr/share/games/stockfish/" make -j ARCH=x86-64 profile-build

passed STC non-regression:
https://tests.stockfishchess.org/tests/view/5f4a581c150f0aef5f8ae03a
LLR: 2.95 (-2.94,2.94) {-1.25,-0.25}
Total: 66928 W: 7202 L: 7147 D: 52579
Ptnml(0-2): 291, 5309, 22211, 5360, 293

closes https://github.com/official-stockfish/Stockfish/pull/3070

fixes https://github.com/official-stockfish/Stockfish/issues/3030

No functional change.

22 months agoSimplify MCP in QS
VoyagerOne [Tue, 25 Aug 2020 13:10:47 +0000 (09:10 -0400)]
Simplify MCP in QS

Simplify moveCount pruning in QS by removing depth dependency.

STC
LLR: 2.94 (-2.94,2.94) {-1.25,0.25}
Total: 42960 W: 4741 L: 4661 D: 33558
Ptnml(0-2): 218, 3574, 13804, 3678, 206
https://tests.stockfishchess.org/tests/view/5f42e3f75089a564a10d8493

LTC
LLR: 2.94 (-2.94,2.94) {-0.75,0.25}
Total: 66672 W: 3563 L: 3508 D: 59601
Ptnml(0-2): 71, 3064, 26996, 3149, 56
https://tests.stockfishchess.org/tests/view/5f4353285089a564a10d84d0

closes https://github.com/official-stockfish/Stockfish/pull/3067

Bench: 4074430

22 months agoRemove Reduce Depth
VoyagerOne [Sun, 23 Aug 2020 16:04:50 +0000 (12:04 -0400)]
Remove Reduce Depth

Remove Reduce Depth at PV nodes.

STC:
LLR: 2.94 (-2.94,2.94) {-1.25,0.25}
Total: 56760 W: 6299 L: 6236 D: 44225
Ptnml(0-2): 286, 4843, 18076, 4872, 303
https://tests.stockfishchess.org/tests/view/5f41356087a5c3c63d8f53c9

LTC:
LLR: 2.95 (-2.94,2.94) {-0.75,0.25}
Total: 17496 W: 954 L: 865 D: 15677
Ptnml(0-2): 13, 768, 7098, 855, 14
https://tests.stockfishchess.org/tests/view/5f41bb7687a5c3c63d8f53f9

closes https://github.com/official-stockfish/Stockfish/pull/3055

Bench: 3555051

22 months agoRemove EvalList
syzygy1 [Mon, 24 Aug 2020 00:29:38 +0000 (02:29 +0200)]
Remove EvalList

This patch removes the EvalList structure from the Position object and generally simplifies the interface between do_move() and the NNUE code.

The NNUE evaluation function first calculates the "accumulator". The accumulator consists of two halves: one for white's perspective, one for black's perspective.

If the "friendly king" has moved or the accumulator for the parent position is not available, the accumulator for this half has to be calculated from scratch. To do this, the NNUE node needs to know the positions and types of all non-king pieces and the position of the friendly king. This information can easily be obtained from the Position object.

If the "friendly king" has not moved, its half of the accumulator can be calculated by incrementally updating the accumulator for the previous position. For this, the NNUE code needs to know which pieces have been added to which squares and which pieces have been removed from which squares. In principle this information can be derived from the Position object and StateInfo struct (in the same way as undo_move() does this). However, it is probably a bit faster to prepare this information in do_move(), so I have kept the DirtyPiece struct. Since the DirtyPiece struct now stores the squares rather than "PieceSquare" indices, there are now at most three "dirty pieces" (previously two). A promotion move that captures a piece removes the capturing pawn and the captured piece from the board (to SQ_NONE) and moves the promoted piece to the promotion square (from SQ_NONE).

An STC test has confirmed a small speedup:

https://tests.stockfishchess.org/tests/view/5f43f06b5089a564a10d850a
LLR: 2.94 (-2.94,2.94) {-0.25,1.25}
Total: 87704 W: 9763 L: 9500 D: 68441
Ptnml(0-2): 426, 6950, 28845, 7197, 434

closes https://github.com/official-stockfish/Stockfish/pull/3068

No functional change

22 months agoCheck ARCH=.... variable
Joost VandeVondele [Mon, 24 Aug 2020 19:32:04 +0000 (21:32 +0200)]
Check ARCH=.... variable

to prevent user errors or generating untested code,
check explicitly that the ARCH variable is equivalent to a supported architecture
as listed in `make help`.

To nevertheless compile for an untested target the user can override the internal
variable, passing the undocumented `SUPPORTED_ARCH=true` to make.

closes https://github.com/official-stockfish/Stockfish/pull/3062

No functional change.

22 months agoAllow for VNNI256 compilation with g++-8
mstembera [Mon, 24 Aug 2020 10:38:01 +0000 (03:38 -0700)]
Allow for VNNI256 compilation with g++-8

explicitly pass needed -mavx512f -mavx512bw flags

closes https://github.com/official-stockfish/Stockfish/pull/3061

No functional change

22 months agoIntroduce countermove based pruning for qsearch
Vizvezdenec [Mon, 24 Aug 2020 05:04:16 +0000 (08:04 +0300)]
Introduce countermove based pruning for qsearch

This patch continues work of previous patch in introducing pruning heuristics in qsearch by analogy to main search, now with countermove based pruning.
Idea is that if move is late enough and is quite check (we do generate them in qsearch) and has bad enough countermove history - prune it.

passed STC
https://tests.stockfishchess.org/tests/view/5f41220287a5c3c63d8f53c5
LLR: 2.93 (-2.94,2.94) {-0.25,1.25}
Total: 35944 W: 4127 L: 3929 D: 27888
Ptnml(0-2): 196, 2970, 11459, 3134, 213

passed LTC
https://tests.stockfishchess.org/tests/view/5f41862f87a5c3c63d8f53e8
LLR: 2.95 (-2.94,2.94) {0.25,1.25}
Total: 138448 W: 7655 L: 7252 D: 123541
Ptnml(0-2): 145, 6247, 56043, 6638, 151

closes https://github.com/official-stockfish/Stockfish/pull/3058

Bench: 3610676

22 months agoAllow TT entries with key16==0 to be fetched
Sami Kiminki [Fri, 21 Aug 2020 09:12:39 +0000 (12:12 +0300)]
Allow TT entries with key16==0 to be fetched

Fix the issue where a TT entry with key16==0 would always be reported
as a miss. Instead, we'll use depth8 to detect whether the TT entry is
occupied. In order to do that, we'll change DEPTH_OFFSET to -7
(depth8==0) to distinguish between an unoccupied entry and the
otherwise lowest possible depth, i.e., DEPTH_NONE (depth8==1).

To prevent a performance regression, we'll reorder the TT entry fields
by the access order of TranspositionTable::probe(). Memory in general
works fastest when accessed in sequential order. We'll also match the
store order in TTEntry::save() with the entry field order, and
re-order the 'if-or' expressions in TTEntry::save() from the cheapest
to the most expensive.

Finally, as we now have a proper TT entry occupancy test, we'll fix a
minor corner case with hashfull reporting. To reproduce:
- Use a big hash
- Either:
  a. Start 31 very quick searches (this wraparounds generation to 0); or
  b. Force generation of the first search to 0.
- go depth infinite

Before the fix, hashfull would incorrectly report nearly full hash
immediately after the search start, since
TranspositionTable::hashfull() used to consider only the entry
generation and not whether the entry was actually occupied.

STC:
LLR: 2.95 (-2.94,2.94) {-0.25,1.25}
Total: 36848 W: 4091 L: 3898 D: 28859
Ptnml(0-2): 158, 2996, 11972, 3091, 207
https://tests.stockfishchess.org/tests/view/5f3f98d5dc02a01a0c2881f7

LTC:
LLR: 2.95 (-2.94,2.94) {0.25,1.25}
Total: 32280 W: 1828 L: 1653 D: 28799
Ptnml(0-2): 34, 1428, 13051, 1583, 44
https://tests.stockfishchess.org/tests/view/5f3fe77a87a5c3c63d8f5332

closes https://github.com/official-stockfish/Stockfish/pull/3048

Bench: 3760677

22 months agoSupport VNNI on 256bit vectors
mstembera [Thu, 20 Aug 2020 23:59:27 +0000 (16:59 -0700)]
Support VNNI on 256bit vectors

due to downclocking on current chips (tested up to cascade lake)
supporting avx512 and vnni512, it is better to use avx2 or vnni256
in multithreaded (in particular hyperthreaded) engine use.
In single threaded use, the picture is different.

gcc compilation for vnni256 requires a toolchain for gcc >= 9.

closes https://github.com/official-stockfish/Stockfish/pull/3038

No functional change

22 months agoarmv8 AArch64 does not require -mfpu=neon
George Sobala [Mon, 24 Aug 2020 05:37:42 +0000 (06:37 +0100)]
armv8 AArch64 does not require -mfpu=neon

-mpfu is not required on AArch64 / armv8 architecture on Linux and throws an error if present.
This PR has been tested on gcc and clang on Gentoo-64 and Raspian-64 on a Raspberry Pi 4,
as well as with a cross from Ubuntu
(`make clean && make -j build ARCH=armv8         COMP=gcc COMPILER=aarch64-linux-gnu-g++`)

fixes https://github.com/official-stockfish/Stockfish/issues/3056
closes https://github.com/official-stockfish/Stockfish/pull/3059

No functional change

22 months agoIntroduce movecount pruning for qsearch()
Vizvezdenec [Sun, 23 Aug 2020 11:22:32 +0000 (14:22 +0300)]
Introduce movecount pruning for qsearch()

If in quiescence search, we assume that me can prune late moves when:

a) the move ordering count of the move is : moveCount > abs(depth) + 2
b) we are not in check
c) the late move does not give check
d) the late move is not an advanced pawn push

Modification of an original idea by @VoyagerOne.

STC
https://tests.stockfishchess.org/tests/view/5f40581787a5c3c63d8f535f
LLR: 2.96 (-2.94,2.94) {-0.25,1.25}
Total: 132848 W: 14999 L: 14661 D: 103188
Ptnml(0-2): 684, 11242, 42309, 11430, 759

LTC
https://tests.stockfishchess.org/tests/view/5f4226da87a5c3c63d8f5412
LLR: 2.98 (-2.94,2.94) {0.25,1.25}
Total: 12008 W: 678 L: 551 D: 10779
Ptnml(0-2): 8, 485, 4899, 596, 16

closes https://github.com/official-stockfish/Stockfish/pull/3053

Bench: 3749974

22 months agoSkip the alignment bug workaround for Clang
syzygy1 [Sat, 22 Aug 2020 11:36:34 +0000 (13:36 +0200)]
Skip the alignment bug workaround for Clang

Clang-10.0.0 poses as gcc-4.2:

$ clang++ -E -dM - </dev/null | grep GNUC

This means that Clang is using the workaround for the alignment bug of gcc-8
even though it does not have the bug (as far as I know).

This patch should speed up AVX2 and AVX512 compiles on Windows (when using Clang),
because it disables (for Clang) the gcc workaround we had introduced in this commit:
https://github.com/official-stockfish/Stockfish/commit/875183b310a8249922c2155e82cb4cecfae2097e

closes https://github.com/official-stockfish/Stockfish/pull/3050

No functional change.

22 months agoSmall trivial cleanups
Joost VandeVondele [Sat, 11 Jul 2020 14:59:33 +0000 (16:59 +0200)]
Small trivial cleanups

closes https://github.com/official-stockfish/Stockfish/pull/2801

No functional change

22 months agoInstructions to build on older Macintosh
Stéphane Nicolet [Sat, 22 Aug 2020 09:37:53 +0000 (11:37 +0200)]
Instructions to build on older Macintosh

In recent Macs, it is possible to use the Clang compiler provided by Apple
to compile Stockfish out of the box, and this is the method used by default
in our Makefile (the Makefile sets the macosx-version-min=10.14 flag to select
the right libc++ library for the Clang compiler with recent c++17 support).

But it is quite possible to compile and run Stockfish on older Macs! Below
we describe a method to install a recent GNU compiler on these Macs, to get
the c++17 support. We have tested the following procedure to install gcc10 on
machines running Mac OS 10.7, Mac OS 10.9 and Mac OS 10.13:

1) install XCode for your machine.

2) install Apple command-line developer tools for XCode, by typing the following
   command in a Terminal:

```
      sudo xcode-select --install
```

3) go to the Stockfish "src" directory, then try a default build and run Stockfish:

```
      make clean
      make build
      make net
      ./stockfish
```

4) if step 3 worked, congrats! You have a compiler recent enough on your Mac
to compile Stockfish. If not, continue with step 5 to install GNU gcc10 :-)

5) install the MacPorts package manager (https://www.macports.org/install.php),
for instance using the fast method in the "macOS Package (.pkg) Installer"
section of the page.

6) use the "port" command to install the gcc10 package of MacPorts by typing the
following command:

```
    sudo port install gcc10
```

With this step, MacPorts will install the gcc10 compiler under the name "g++-mp-10"
in the /opt/local/bin directory:

```
   which g++-mp-10

   /opt/local/bin/g++-mp-10       <--- answer
```

7) You can now go back to the "src" directory of Stockfish, and try to build
Stockfish by pointing at the right compiler:

```
   make clean
   make build COMP=gcc COMPCXX=/opt/local/bin/g++-mp-10
   make net
   ./stockfish
```

8) Enjoy Stockfish on Macintosh!

See this pull request for further discussion:
https://github.com/official-stockfish/Stockfish/pull/3049

No functional change

22 months agoExplicitly rely on pthreads if possible
Joost VandeVondele [Fri, 21 Aug 2020 20:10:55 +0000 (22:10 +0200)]
Explicitly rely on pthreads if possible

allows us to set the needed stacksize on thread creation.

Useful for environments with too small a default stack size (e.g. Alpine Linux with musl).

Passed STC, no regression:

LLR: 2.96 (-2.94,2.94) {-1.25,0.25}
Total: 17816 W: 1344 L: 1275 D: 15197
Ptnml(0-2): 30, 1057, 6682, 1092, 47
https://tests.stockfishchess.org/tests/view/5f402b5587a5c3c63d8f534d

closes https://github.com/official-stockfish/Stockfish/pull/3047

fixes https://github.com/official-stockfish/Stockfish/issues/3041

No functional change.

22 months agoDisplay classic and NNUE evaluation in trace mode
MJZ1977 [Fri, 21 Aug 2020 08:57:34 +0000 (10:57 +0200)]
Display classic and NNUE evaluation in trace mode

show both the classical and NNUE evaluation,
as well as the Final evaluation.

closes https://github.com/official-stockfish/Stockfish/pull/3042

No functional change.

22 months agoSimplify away internal iterative deepening
Unai Corzo [Fri, 21 Aug 2020 07:24:25 +0000 (09:24 +0200)]
Simplify away internal iterative deepening

Remove the iterative deepening step.
Instead, employ a depth reduction if the position is not in TT and on the PV.

STC https://tests.stockfishchess.org/tests/view/5f3ce6eaa95672ddd56c637e
LLR: 2.97 (-2.94,2.94) {-0.50,1.50}
Total: 41096 W: 4421 L: 4257 D: 32418
Ptnml(0-2): 207, 3259, 13460, 3407, 215

LTC (old) https://tests.stockfishchess.org/tests/view/5f3d7d4fa95672ddd56c640b
LLR: 2.92 (-2.94,2.94) {-1.50,0.50}
Total: 26032 W: 1320 L: 1309 D: 23403
Ptnml(0-2): 22, 1152, 10654, 1169, 19

LTC (new) https://tests.stockfishchess.org/tests/view/5f3e31e0a95672ddd56c6464
LLR: 2.95 (-2.94,2.94) {-0.75,0.25}
Total: 34160 W: 1844 L: 1766 D: 30550
Ptnml(0-2): 33, 1533, 13876, 1599, 39

bench: 3849173

22 months agoUpdate Makefile for macOS
gsobala [Fri, 21 Aug 2020 10:28:53 +0000 (11:28 +0100)]
Update Makefile for macOS

Changes to deal with compilation (particularly profile-build) on macOS.
(1) The default toolchain has gcc masquerading as clang,
    the previous Makefile was not picking up the required changes
    to the different profiling tools.
(2) The previous Makefile test for gccisclang occurred before
    a potential overwrite of CXX by COMPCXX
(3) llvm-profdata no longer runs as a command on macOS and
    instead is invoked by ``xcrun llvm-profdata``
(4) Needs to support use of true gcc using e.g.
    ``make build ... COMPCXX=g++-10``
(5) enable profile-build in travis for macOS

closes https://github.com/official-stockfish/Stockfish/pull/3043

No functional change

22 months agoDeal with very old linux kernels
Joost VandeVondele [Fri, 21 Aug 2020 05:42:19 +0000 (07:42 +0200)]
Deal with very old linux kernels

MADV_HUGEPAGE might not be available, for kernels before 2.6.38 (released 2011). Just skip the madvise.

closes https://github.com/official-stockfish/Stockfish/pull/3039

No functional change

22 months agoSet Use NNUE by default to true
Joost VandeVondele [Thu, 20 Aug 2020 12:24:49 +0000 (14:24 +0200)]
Set Use NNUE by default to true

Since the initial stages of the merge, progress has been made so that
this seems the best option now:

* NNUE is clearly stronger on most relevant hardware and time controls
* All of our CI and testing infrastructure has been adjusted
* The default net is easy to get (further ideas #3030)

fixes https://github.com/official-stockfish/Stockfish/issues/2861

closes https://github.com/official-stockfish/Stockfish/pull/3033

No functional change.

22 months agoSend error message as an UCI info string
Joost VandeVondele [Wed, 19 Aug 2020 17:21:41 +0000 (19:21 +0200)]
Send error message as an UCI info string

some GUIs do not show the error message when the engine terminates in the no-net case, as it is send to cerr.
Instead send it as an info string, which the GUI will more likely display.

closes https://github.com/official-stockfish/Stockfish/pull/3031

No functional change.

22 months agoReintroduce last captures extension
SFisGOD [Tue, 18 Aug 2020 10:54:28 +0000 (18:54 +0800)]
Reintroduce last captures extension

STC:
LLR: 2.93 (-2.94,2.94) {-0.50,1.50}
Total: 34840 W: 3834 L: 3682 D: 27324
Ptnml(0-2): 153, 2767, 11455, 2865, 180
https://tests.stockfishchess.org/tests/view/5f3bb380b38d442594aabefc

LTC:
LLR: 2.95 (-2.94,2.94) {0.25,1.75}
Total: 15832 W: 890 L: 776 D: 14166
Ptnml(0-2): 17, 669, 6429, 785, 16
https://tests.stockfishchess.org/tests/view/5f3c46a0a95672ddd56c632a

closes https://github.com/official-stockfish/Stockfish/pull/3028

see also https://github.com/official-stockfish/Stockfish/pull/3020

Bench: 4348811

22 months agoExpanded support for x86-32 architectures.
syzygy1 [Mon, 17 Aug 2020 23:56:12 +0000 (01:56 +0200)]
Expanded support for x86-32 architectures.

add new ARCH targets

x86-32-sse41-popcnt     > x86 32-bit with sse41 and popcnt support
x86-32-sse2             > x86 32-bit with sse2 support
x86-32                  > x86 32-bit generic (with mmx and sse support)

retire x86-32-old (use general-32)

closes https://github.com/official-stockfish/Stockfish/pull/3022

No functional change.

22 months agoBetter error message on missing curl/wget
Joost VandeVondele [Tue, 18 Aug 2020 16:06:28 +0000 (18:06 +0200)]
Better error message on missing curl/wget

provide clean error/warning message for missing curl/wget, sha256sum/shasum

fixes https://github.com/official-stockfish/Stockfish/issues/3025

closes https://github.com/official-stockfish/Stockfish/pull/3026

No functional change

22 months agoFix Makefile typo
Joost VandeVondele [Tue, 18 Aug 2020 06:49:06 +0000 (08:49 +0200)]
Fix Makefile typo

remove stray quote, shown with `make help`

No functional change

22 months agoFallback to NNUE
mstembera [Sun, 16 Aug 2020 22:23:50 +0000 (15:23 -0700)]
Fallback to NNUE

If the classical eval ends up much smaller than estimated fall back to NNUE.
Also use multiply instead of divide for the threshold comparison for smoother transitions without rounding.

STC https://tests.stockfishchess.org/tests/view/5f3a5011b38d442594aabdfe
LLR: 2.96 (-2.94,2.94) {-0.50,1.50}
Total: 57352 W: 6325 L: 6135 D: 44892
Ptnml(0-2): 277, 4748, 18482, 4846, 323

LTC https://tests.stockfishchess.org/tests/view/5f3aee9db38d442594aabe82
LLR: 2.95 (-2.94,2.94) {0.25,1.75}
Total: 16232 W: 897 L: 781 D: 14554
Ptnml(0-2): 19, 679, 6616, 771, 31

closes https://github.com/official-stockfish/Stockfish/pull/3023

bench: 4026216

-----

Recommended net: https://tests.stockfishchess.org/api/nn/nn-82215d0fd0df.nnue

22 months agoRemove last captures extension
Unai Corzo [Mon, 17 Aug 2020 16:22:32 +0000 (18:22 +0200)]
Remove last captures extension

STC https://tests.stockfishchess.org/tests/view/5f395657e98b6c64b3df41dd
LLR: 2.95 (-2.94,2.94) {-1.50,0.50}
Total: 144664 W: 15426 L: 15537 D: 113701
Ptnml(0-2): 612, 11341, 48537, 11230, 612

LTC https://tests.stockfishchess.org/tests/view/5f3a2ec7b38d442594aabdd7
LLR: 2.96 (-2.94,2.94) {-1.50,0.50}
Total: 22728 W: 1161 L: 1146 D: 20421
Ptnml(0-2): 21, 960, 9388, 973, 22

closes https://github.com/official-stockfish/Stockfish/pull/3020

bench: 3832662

22 months agoRemove history bonus from Eval
VoyagerOne [Mon, 17 Aug 2020 12:58:03 +0000 (08:58 -0400)]
Remove history bonus from Eval

STC:
LLR: 2.92 (-2.94,2.94) {-1.50,0.50}
Total: 26776 W: 2787 L: 2725 D: 21264
https://tests.stockfishchess.org/tests/view/5f39d6beb38d442594aabd9b

LTC:
LLR: 2.93 (-2.94,2.94) {-1.50,0.50}
Total: 12968 W: 635 L: 608 D: 11725
https://tests.stockfishchess.org/tests/view/5f39decfb38d442594aabda7

closes https://github.com/official-stockfish/Stockfish/pull/3019

Bench:  4335100

22 months agoSupport building for Android using NDK
notruck [Sun, 16 Aug 2020 15:59:13 +0000 (08:59 -0700)]
Support building for Android using NDK

The easiest way to use the NDK in conjunction with this Makefile (tested on linux-x86_64):

1. Download the latest NDK (r21d) from Google from https://developer.android.com/ndk/downloads
2. Place and unzip the NDK in $HOME/ndk folder
3. Export the path variable e.g., `export PATH=$PATH:$HOME/ndk/android-ndk-r21d/toolchains/llvm/prebuilt/linux-x86_64/bin`
4. cd to your Stockfish/src dir
5. Issue `make -j ARCH=armv8 COMP=ndk build`  (use `ARCH=armv7` or `ARCH=armv7-neon` for older CPUs)
6. Optionally `make -j ARCH=armv8 COMP=ndk strip`
7. That's all. Enjoy!

Improves support from Raspberry Pi (incomplete?) and compiling on arm in general

closes https://github.com/official-stockfish/Stockfish/pull/3015

fixes https://github.com/official-stockfish/Stockfish/issues/2860

fixes https://github.com/official-stockfish/Stockfish/issues/2641

Support is still fragile as we're missing CI on these targets. Nevertheless tested with:

```bash
  # build crosses from ubuntu 20.04 on x86 to various arch/OS combos
  # tested with suitable packages installed
  # (build-essentials, mingw-w64, g++-arm-linux-gnueabihf, NDK (r21d) from google)

  # cross to Android
  export PATH=$HOME/ndk/android-ndk-r21d/toolchains/llvm/prebuilt/linux-x86_64/bin:$PATH
  make clean && make -j build ARCH=armv7         COMP=ndk  && make -j build ARCH=armv7 COMP=ndk strip
  make clean && make -j build ARCH=armv7-neon    COMP=ndk  && make -j build ARCH=armv7-neon COMP=ndk strip
  make clean && make -j build ARCH=armv8         COMP=ndk  && make -j build ARCH=armv8 COMP=ndk strip

  # cross to Raspberry Pi
  make clean && make -j build ARCH=armv7         COMP=gcc COMPILER=arm-linux-gnueabihf-g++
  make clean && make -j build ARCH=armv7-neon    COMP=gcc COMPILER=arm-linux-gnueabihf-g++

  # cross to Windows
  make clean && make -j build ARCH=x86-64-modern COMP=mingw
```

No functional change

22 months agoSimplify away the passed pawn extension
Unai Corzo [Mon, 17 Aug 2020 07:22:15 +0000 (09:22 +0200)]
Simplify away the passed pawn extension

STC https://tests.stockfishchess.org/tests/view/5f3955f0e98b6c64b3df41d7
LLR: 2.96 (-2.94,2.94) {-1.50,0.50}
Total: 31992 W: 3611 L: 3548 D: 24833
Ptnml(0-2): 174, 2658, 10273, 2713, 178

LTC https://tests.stockfishchess.org/tests/view/5f399e41e98b6c64b3df4210
LLR: 3.01 (-2.94,2.94) {-1.50,0.50}
Total: 29568 W: 1488 L: 1480 D: 26600
Ptnml(0-2): 40, 1272, 12142, 1300, 30

closes https://github.com/official-stockfish/Stockfish/pull/3017

bench: 3844671

-----

Recommended net: https://tests.stockfishchess.org/api/nn/nn-82215d0fd0df.nnue

22 months agoReformat code in little-endian patch
Stéphane Nicolet [Sun, 16 Aug 2020 19:46:54 +0000 (21:46 +0200)]
Reformat code in little-endian patch

Reformat code and rename the function to "read_little_endian()" in the recent
commit by Ronald de Man for support of big endian systems.

closes https://github.com/official-stockfish/Stockfish/pull/3016

No functional change
-----

Recommended net: https://tests.stockfishchess.org/api/nn/nn-82215d0fd0df.nnue

22 months agoAdd further targets to travis testing
Joost VandeVondele [Sun, 16 Aug 2020 11:21:07 +0000 (13:21 +0200)]
Add further targets to travis testing

general-32, general-64 and help

closes https://github.com/official-stockfish/Stockfish/pull/3014

No functional change

22 months agoAssume network file is in little-endian byte order
syzygy1 [Sat, 15 Aug 2020 14:50:39 +0000 (16:50 +0200)]
Assume network file is in little-endian byte order

This patch fixes the byte order when reading 16- and 32-bit values from the network file on a big-endian machine.

Bytes are ordered in read_le() using unsigned arithmetic, which doesn't need tricks to determine the endianness of the machine. Unfortunately the compiler doesn't seem to be able to optimise the ordering operation, but reading in the weights is not a time-critical operation and the extra time it takes should not be noticeable.

Big endian systems are still untested with NNUE.

fixes #3007

closes https://github.com/official-stockfish/Stockfish/pull/3009

No functional change.

22 months agoDisplay NEON in compiler string
Daylen Yang [Sat, 15 Aug 2020 02:53:46 +0000 (19:53 -0700)]
Display NEON in compiler string

if NEON intrinsics are being used and USE_NEON is defined.

closes https://github.com/official-stockfish/Stockfish/pull/3008

No functional change

22 months agoUse NNUE more for fortresses
Joost VandeVondele [Fri, 14 Aug 2020 20:18:12 +0000 (22:18 +0200)]
Use NNUE more for fortresses

Increases the use of NNUE evaluation in positions without captures/pawn moves,
by increasing the NNUEThreshold threshold with rule50_count.

This patch will force Stockfish to use NNUE eval more and more in materially
unbalanced positions, when it seems that the classical eval is struggling to
win and only manages to shuffle. This will ask the (slower) NNUE eval to
double-check the potential fortress branches of the search tree, but only
when necessary.

passed STC:
https://tests.stockfishchess.org/tests/view/5f36f1bf11a9b1a1dbf192d8
LLR: 2.93 (-2.94,2.94) {-0.50,1.50}
Total: 51824 W: 5836 L: 5653 D: 40335
Ptnml(0-2): 264, 4356, 16512, 4493, 287

passed LTC:
https://tests.stockfishchess.org/tests/view/5f37836111a9b1a1dbf1936d
LLR: 2.93 (-2.94,2.94) {0.25,1.75}
Total: 29768 W: 1747 L: 1590 D: 26431
Ptnml(0-2): 33, 1347, 11977, 1484, 43

closes https://github.com/official-stockfish/Stockfish/pull/3011

Bench: 4173967

22 months agoTry to match relative magnitude of NNUE eval to classical
mstembera [Fri, 14 Aug 2020 11:49:33 +0000 (04:49 -0700)]
Try to match relative magnitude of NNUE eval to classical

The idea is that since we are mixing NNUE and classical evals matching their magnitudes closer allows for better comparisons.

STC https://tests.stockfishchess.org/tests/view/5f35a65411a9b1a1dbf18e2b
LLR: 2.94 (-2.94,2.94) {-0.50,1.50}
Total: 9840 W: 1150 L: 1027 D: 7663
Ptnml(0-2): 49, 772, 3175, 855, 69

LTC https://tests.stockfishchess.org/tests/view/5f35bcbe11a9b1a1dbf18e47
LLR: 2.93 (-2.94,2.94) {0.25,1.75}
Total: 44424 W: 2492 L: 2294 D: 39638
Ptnml(0-2): 42, 2015, 17915, 2183, 57

also corrects the location to clamp the evaluation (non-function on bench).

closes https://github.com/official-stockfish/Stockfish/pull/3003

bench: 3905447

22 months agoAlso dampen NNUE eval with 50 move rule
Miguel Lahoz [Mon, 10 Aug 2020 14:57:11 +0000 (22:57 +0800)]
Also dampen NNUE eval with 50 move rule

Move the existing dampening function last so that NNUE evaluations are
also handled as we approach the 50 move rule.

STC:
LLR: 2.95 (-2.94,2.94) {-0.50,1.50}
Total: 4792 W: 695 L: 561 D: 3536
Ptnml(0-2): 19, 420, 1422, 478, 57
https://tests.stockfishchess.org/tests/view/5f3164179081672066537534

LTC:
LLR: 8.62 (-2.94,2.94) {0.25,1.75}
Total: 286744 W: 18494 L: 17430 D: 250820
Ptnml(0-2): 418, 14886, 111745, 15860, 463
https://tests.stockfishchess.org/tests/view/5f316b039081672066537541

closes https://github.com/official-stockfish/Stockfish/pull/3004

Bench: 4001800

22 months agoVerify SHA of downloaded net file
Joost VandeVondele [Thu, 13 Aug 2020 20:54:13 +0000 (22:54 +0200)]
Verify SHA of downloaded net file

check SHA of the available and downloaded file.

Document the format requirement on the default net.

Also allow curl to make possibly insecure connections, as needed for old curl.

fixes https://github.com/official-stockfish/Stockfish/issues/2998

closes https://github.com/official-stockfish/Stockfish/pull/3000

No functional change.

22 months agoClean-up Makefile help
Stéphane Nicolet [Thu, 13 Aug 2020 11:40:06 +0000 (13:40 +0200)]
Clean-up Makefile help

Do not show the details of the default architecture for a simple "make help"
invocation, as the details are most likely to confuse beginners. Instead we
make it clear which architecture is the default and put an example at the end
of the Makefile as an incentative to use "make help ARCH=blah" to discover
the flags used by the different architectures.

```
    make help
    make help ARCH=x86-64-ssse3
```

Also clean-up and modernize a bit the Makefile examples while at it.

closes https://github.com/official-stockfish/Stockfish/pull/2996

No functional change

22 months agoUpdate default net to nn-82215d0fd0df.nnue
Sergio Vieri [Wed, 12 Aug 2020 15:21:21 +0000 (23:21 +0800)]
Update default net to nn-82215d0fd0df.nnue

Net created at: 20200812-2257

passed STC: https://tests.stockfishchess.org/tests/view/5f340ca99e5f2effc089da17
LLR: 2.96 (-2.94,2.94) {-0.50,1.50}
Total: 5744 W: 756 L: 627 D: 4361
Ptnml(0-2): 28, 485, 1731, 586, 42

passed LTC: https://tests.stockfishchess.org/tests/view/5f341eba9e5f2effc089da23
LLR: 2.94 (-2.94,2.94) {0.25,1.75}
Total: 17136 W: 1041 L: 917 D: 15178
Ptnml(0-2): 13, 813, 6807, 907, 28

closes https://github.com/official-stockfish/Stockfish/pull/2992

Bench: 3935117

22 months agoOutput the SSE2 flag in compiler_info
Joost VandeVondele [Wed, 12 Aug 2020 15:21:12 +0000 (17:21 +0200)]
Output the SSE2 flag in compiler_info

was missing in the list of outputs, slightly reorder flags.
explicitly add -msse2 if USE_SSE2 (is implicit already, -msse -m64).

closes https://github.com/official-stockfish/Stockfish/pull/2990

No functional change.

22 months agoAdd support for VNNI
mstembera [Tue, 11 Aug 2020 19:59:39 +0000 (12:59 -0700)]
Add support for VNNI

Adds support for Vector Neural Network Instructions (avx512), as available on Intel Cascade Lake

The _mm512_dpbusd_epi32() intrinsic (vpdpbusd instruction) is taylor made for NNUE.

on a cascade lake CPU (AWS C5.24x.large, gcc 10) NNUE eval is at roughly 78% nps of classical
(single core test)

bench 1024 1 24 default depth:
target  classical  NNUE  ratio
vnni  2207232  1725987  78.20
avx512  2216789  1671734  75.41
avx2  2194006  1611263  73.44
modern  2185001  1352469  61.90

closes https://github.com/official-stockfish/Stockfish/pull/2987

No functional change

22 months agoUse posix_memalign for Apple Silicon instead of _mm_malloc
Daylen Yang [Tue, 11 Aug 2020 19:02:48 +0000 (12:02 -0700)]
Use posix_memalign for Apple Silicon instead of _mm_malloc

fails to build on that target, because of missing Intel Intrinsics.
macOS has posix_memalign() since ~2014 so we can simplify the code and just use that for all Apple platforms.

closes https://github.com/official-stockfish/Stockfish/pull/2985

No functional change.

22 months agoRestrict avx2 hack to windows target
Joost VandeVondele [Tue, 11 Aug 2020 19:11:17 +0000 (21:11 +0200)]
Restrict avx2 hack to windows target

this workaround is possibly rather a windows & gcc specific problem. See e.g.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54412#c25

on Linux with gcc 8 this patch brings roughly a 8% speedup.
However, probably needs some testing in the wild.

includes a workaround for an old msys make (3.81) installation (fixes #2984)

No functional change

22 months agoTweak castling extension
SFisGOD [Mon, 10 Aug 2020 13:13:56 +0000 (21:13 +0800)]
Tweak castling extension

Change condition from three friendly pieces to two. This now means that we only extend castling on the king side if there are no other friendly pieces aside from king and rook. For the queen side, we only extend if there is only a rook and another friendly piece or if there is only a single rook and no other friendly piece but this is very rare.

STC:
LLR: 3.20 (-2.94,2.94) {-0.50,1.50}
Total: 31144 W: 4086 L: 3903 D: 23155
Ptnml(0-2): 227, 2843, 9278, 2968, 256
https://tests.stockfishchess.org/tests/view/5f31487f9081672066537516

LTC:
LLR: 2.93 (-2.94,2.94) {0.25,1.75}
Total: 57816 W: 3786 L: 3538 D: 50492
Ptnml(0-2): 92, 2991, 22488, 3251, 86
https://tests.stockfishchess.org/tests/view/5f3167c3908167206653753d

closes https://github.com/official-stockfish/Stockfish/pull/2980

Bench: 4244812

22 months agoThis commit enables a mixed bench, to improve CI and allow for PGO (profile-build...
Guy Vreuls [Fri, 7 Aug 2020 15:07:46 +0000 (17:07 +0200)]
This commit enables a mixed bench, to improve CI and allow for PGO (profile-build) of the NNUE part of the code.

Joint work gvreuls / vondele

* Download the default NNUE net in AppVeyor
* Download net in travis CI `make net`
* Adjust tests to cover more archs, speedup instrumented testing
* Introduce 'mixed' bench as default, with further options:

classical, NNUE, mixed.

mixed (default) and NNUE require the default net to be present,
which can be obtained with

```
make net
```

Further examples (first is equivalent to `./stockfish bench`):

```
./stockfish bench 16 1 13 default depth mixed
./stockfish bench 16 1 13 default depth classical
./stockfish bench 16 1 13 default depth NNUE
```

The net is now downloaded automatically if needed for `profile-build`
(usual `build` works fine without net present)

PGO gives a nice speedup on fishtest:

passed STC:
LLR: 2.93 (-2.94,2.94) {-0.50,1.50}
Total: 3360 W: 469 L: 343 D: 2548
Ptnml(0-2): 20, 246, 1030, 356, 28
https://tests.stockfishchess.org/tests/view/5f31b5499081672066537569

passed LTC:
LLR: 2.97 (-2.94,2.94) {0.25,1.75}
Total: 8824 W: 609 L: 502 D: 7713
Ptnml(0-2): 8, 430, 3438, 519, 17
https://tests.stockfishchess.org/tests/view/5f31c87b908167206653757c

closes https://github.com/official-stockfish/Stockfish/pull/2931

fixes https://github.com/official-stockfish/Stockfish/issues/2907

requires fishtest updates before commit

Bench: 4290577

22 months agoFix AVX512 build with older compilers
mstembera [Mon, 10 Aug 2020 19:52:46 +0000 (12:52 -0700)]
Fix AVX512 build with older compilers

avoids an intrinsic that is missing in gcc < 10.

For this target, might trigger another gcc bug on windows that
requires up-to-date gcc 8, 9, or 10, or usage of clang.

Fixes https://github.com/official-stockfish/Stockfish/issues/2975

closes https://github.com/official-stockfish/Stockfish/pull/2976

No functional change

22 months agoMore aligned_alloc changes to support Android
Joost VandeVondele [Mon, 10 Aug 2020 14:14:17 +0000 (16:14 +0200)]
More aligned_alloc changes to support Android

Move to posix_memalign for those platforms, in particular android,
that do not fully support c++17 std::aligned_alloc() (and are not windows)

see https://github.com/official-stockfish/Stockfish/issues/2860

closes https://github.com/official-stockfish/Stockfish/pull/2973

No functional change

22 months agoFix parallel LTO issues on Windows
Guy Vreuls [Tue, 11 Aug 2020 02:38:38 +0000 (04:38 +0200)]
Fix parallel LTO issues on Windows

This adds -save-temps to the linker flags when parallel LTO is used on
MinGW/MSYS.

fixes #2977

closes https://github.com/official-stockfish/Stockfish/pull/2978

No functional change.

22 months agoAdd comments to probCut code
Vizvezdenec [Sat, 18 Jul 2020 13:30:00 +0000 (16:30 +0300)]
Add comments to probCut code

and rename a variable

closes https://github.com/official-stockfish/Stockfish/pull/2819

No functional change

22 months agoAssorted search parameter tune
Unai Corzo [Mon, 10 Aug 2020 13:38:44 +0000 (15:38 +0200)]
Assorted search parameter tune

STC https://tests.stockfishchess.org/tests/view/5f31219090816720665374ec
LLR: 2.96 (-2.94,2.94) {-0.50,1.50}
Total: 3376 W: 487 L: 359 D: 2530
Ptnml(0-2): 17, 253, 1042, 337, 39

LTC https://tests.stockfishchess.org/tests/view/5f3127f79081672066537502
LLR: 2.93 (-2.94,2.94) {0.25,1.75}
Total: 8360 W: 581 L: 475 D: 7304
Ptnml(0-2): 11, 407, 3238, 513, 11

closes https://github.com/official-stockfish/Stockfish/pull/2971

bench: 4733874

22 months agoProvide vectorized NNUE code for SSE2 and MMX targets
Fanael Linithien [Sun, 9 Aug 2020 14:20:45 +0000 (16:20 +0200)]
Provide vectorized NNUE code for SSE2 and MMX targets

This patch allows old x86 CPUs, from AMD K8 (which the x86-64 baseline
targets) all the way down to the Pentium MMX, to benefit from NNUE with
comparable performance hit versus hand-written eval as on more modern
processors.

NPS of the bench with NNUE enabled on a Pentium III 1.13 GHz (using the
MMX code):
  master: 38951
  this patch: 80586

NPS of the bench with NNUE enabled using baseline x86-64 arch, which is
how linux distros are likely to package stockfish, on a modern CPU
(using the SSE2 code):
  master: 882584
  this patch: 1203945

closes https://github.com/official-stockfish/Stockfish/pull/2956

No functional change.

22 months agoCleanup and optimize SSE/AVX code
mstembera [Sun, 9 Aug 2020 23:23:33 +0000 (16:23 -0700)]
Cleanup and optimize SSE/AVX code

AVX512 +4% faster
AVX2 +1% faster
SSSE3 +5% faster

passed non-regression STC:
STC https://tests.stockfishchess.org/tests/view/5f31249f90816720665374f6
LLR: 2.96 (-2.94,2.94) {-1.50,0.50}
Total: 17576 W: 2344 L: 2245 D: 12987
Ptnml(0-2): 127, 1570, 5292, 1675, 124

closes https://github.com/official-stockfish/Stockfish/pull/2962

No functional change

22 months agoMakefile rework/cleanup
sf-x [Sun, 9 Aug 2020 15:01:18 +0000 (18:01 +0300)]
Makefile rework/cleanup

Makefile targets x86-64-sse42, x86-sse3 are removed; x86-64-sse41
is renamed to x86-64-sse41-popcnt (it did enable popcnt).

Makefile variables sse3, sse42, their associated compilation flags
and code in misc.cpp are removed.

closes https://github.com/official-stockfish/Stockfish/pull/2922

No functional change

22 months agoModify castling extension
SFisGOD [Mon, 10 Aug 2020 07:39:22 +0000 (15:39 +0800)]
Modify castling extension

Extend castling only if there are few friendly pieces on the castling side.

Inspired by silversolver1's (Rahul Dsilva) test
https://tests.stockfishchess.org/tests/view/5f0fef560640035f9d2978cf

STC:
LLR: 2.94 (-2.94,2.94) {-0.50,1.50}
Total: 7096 W: 947 L: 818 D: 5331
Ptnml(0-2): 32, 604, 2181, 665, 66
https://tests.stockfishchess.org/tests/view/5f309f729081672066537426

LTC:
LLR: 2.96 (-2.94,2.94) {0.25,1.75}
Total: 4712 W: 300 L: 215 D: 4197
Ptnml(0-2): 2, 190, 1895, 259, 10
https://tests.stockfishchess.org/tests/view/5f30a2039081672066537430

closes https://github.com/official-stockfish/Stockfish/pull/2970

Bench: 4094850

22 months agoWorkaround using unaligned loads for gcc < 9
mstembera [Mon, 10 Aug 2020 06:50:59 +0000 (23:50 -0700)]
Workaround using unaligned loads for gcc < 9

despite usage of alignas, the generated (avx2/avx512) code with older compilers needs to use
unaligned loads with older gcc (e.g. confirmed crash with gcc 7.3/mingw on abrok).

Better performance thus requires gcc >= 9 on hardware supporting avx2/avx512

closes https://github.com/official-stockfish/Stockfish/pull/2969

No functional change

22 months agosimplying hybrid condition
jjoshua2 [Sun, 9 Aug 2020 20:16:04 +0000 (16:16 -0400)]
simplying hybrid condition

STC https://tests.stockfishchess.org/tests/view/5f3059d1908167206653736b:
LLR: 2.94 (-2.94,2.94) {-1.50,0.50}
Total: 12520 W: 766 L: 727 D: 11027
Ptnml(0-2): 13, 624, 4949, 659, 15

LTC: https://tests.stockfishchess.org/tests/view/5f30863a90816720665373d1
LLR: 2.94 (-2.94,2.94) {-1.50,0.50}
Total: 12520 W: 766 L: 727 D: 11027
Ptnml(0-2): 13, 624, 4949, 659, 15

closes: https://github.com/official-stockfish/Stockfish/pull/2965

Bench: 4084753

22 months agoUpdate default net to nn-112bb1c8cdb5.nnue
Sergio Vieri [Mon, 10 Aug 2020 00:47:52 +0000 (08:47 +0800)]
Update default net to nn-112bb1c8cdb5.nnue

First trained net using search eval instead of pv leaf static eval.

Net created at: 20200810-0744

passed STC: https://tests.stockfishchess.org/tests/view/5f30995d90816720665373f8
LLR: 2.93 (-2.94,2.94) {-0.50,1.50}
Total: 15416 W: 2071 L: 1920 D: 11425
Ptnml(0-2): 123, 1376, 4563, 1519, 127

passed LTC: https://tests.stockfishchess.org/tests/view/5f30a104908167206653742b
LLR: 2.93 (-2.94,2.94) {0.25,1.75}
Total: 29792 W: 2003 L: 1834 D: 25955
Ptnml(0-2): 50, 1541, 11550, 1700, 55

closes https://github.com/official-stockfish/Stockfish/pull/2966

Bench: 4084753

22 months agoRevert "Avoid special casing for MinGW"
Joost VandeVondele [Mon, 10 Aug 2020 05:18:15 +0000 (07:18 +0200)]
Revert "Avoid special casing for MinGW"

This reverts commit a6e89293df5af35931b61d86b6de3872a981c100.

The offending setup has been found as gcc/mingw 7.3 (on Ubuntu 18.04).

fixes https://github.com/official-stockfish/Stockfish/issues/2963

closes https://github.com/official-stockfish/Stockfish/issues/2968

No functional change.

22 months agoFix a data race for NNUE
Joost VandeVondele [Sun, 9 Aug 2020 16:11:38 +0000 (18:11 +0200)]
Fix a data race for NNUE

the stateInfo at the rootPos is no longer read-only, as the NNUE accumulator is part of it.
Threads can thus not share this object and need their own copy.

tested for no regression
https://tests.stockfishchess.org/tests/view/5f3022239081672066536bce
LLR: 2.96 (-2.94,2.94) {-1.50,0.50}
Total: 52800 W: 6843 L: 6802 D: 39155
Ptnml(0-2): 336, 4646, 16399, 4679, 340

closes https://github.com/official-stockfish/Stockfish/pull/2957

fixes https://github.com/official-stockfish/Stockfish/issues/2933

No functional change

22 months agoAvoid special casing for MinGW
Dariusz Orzechowski [Sun, 9 Aug 2020 21:32:24 +0000 (14:32 -0700)]
Avoid special casing for MinGW

after some testing, no version of MinGW/gcc has been found where this code is still necessary.
Probably older code (pre-c++17?)

closes https://github.com/official-stockfish/Stockfish/pull/2891

No functional change

22 months agoAdjust NNUE usage based on number of pawns in position
Vizvezdenec [Sun, 9 Aug 2020 18:39:46 +0000 (21:39 +0300)]
Adjust NNUE usage based on number of pawns in position

The idea of this patch is that positions are usually more complex and hard to evaluate even if there are more pawns.
This patch adjusts NNUE threshold usage depending on number of pawns in position, if pawn count is <3 we use the
classical evaluation more often, for pawn count = 3 patch the is non-functional,
with pawn count > 3 NNUE evaluation is used more often.

passed STC
https://tests.stockfishchess.org/tests/view/5f2f02d09081672066536b1f
LLR: 2.96 (-2.94,2.94) {-0.50,1.50}
Total: 36520 W: 5011 L: 4823 D: 26686
Ptnml(0-2): 299, 3482, 10548, 3594, 337

passed LTC
https://tests.stockfishchess.org/tests/view/5f2f4c329081672066536b5c
LLR: 2.98 (-2.94,2.94) {0.25,1.75}
Total: 39272 W: 2630 L: 2433 D: 34209
Ptnml(0-2): 53, 2066, 15218, 2229, 70

closes https://github.com/official-stockfish/Stockfish/pull/2960

bench 4084753

22 months agoFix aligned_alloc on MinGW
Joost VandeVondele [Sun, 9 Aug 2020 17:08:47 +0000 (19:08 +0200)]
Fix aligned_alloc on MinGW

introduced with d7a26899a973536ab9d3ce4771d8276d1a4dc55c

closes https://github.com/official-stockfish/Stockfish/pull/2959

No functional change.

22 months agoImprove error message on missing net.
Joost VandeVondele [Sun, 9 Aug 2020 09:05:07 +0000 (11:05 +0200)]
Improve error message on missing net.

small rewording, but also print the download url for the default net.

closes https://github.com/official-stockfish/Stockfish/pull/2954

No functional change

22 months agoUse fallback implementation for C++ aligned_alloc
Daniel Dugovic [Sat, 8 Aug 2020 20:39:29 +0000 (15:39 -0500)]
Use fallback implementation for C++ aligned_alloc

fixes https://github.com/official-stockfish/Stockfish/issues/2921

closes https://github.com/official-stockfish/Stockfish/pull/2927

No functional change

22 months agoLMR search tweak
Unai Corzo [Sat, 8 Aug 2020 20:08:40 +0000 (22:08 +0200)]
LMR search tweak

All credit to Vizvezdenec, the original author of the idea.

STC https://tests.stockfishchess.org/tests/view/5f2d606a61e3b6af64881f88
LLR: 2.95 (-2.94,2.94) {-0.50,1.50}
Total: 8440 W: 1191 L: 1048 D: 6201
Ptnml(0-2): 59, 754, 2467, 865, 75

LTC https://tests.stockfishchess.org/tests/view/5f2d84ad61e3b6af64881fbd
LLR: 2.95 (-2.94,2.94) {0.25,1.75}
Total: 21896 W: 1557 L: 1406 D: 18933
Ptnml(0-2): 33, 1185, 8378, 1302, 50

closes https://github.com/official-stockfish/Stockfish/pull/2951

bench: 4084753

22 months agoSingular extension search tweak
Unai Corzo [Sat, 8 Aug 2020 20:03:37 +0000 (22:03 +0200)]
Singular extension search tweak

Tweak depth.

STC https://tests.stockfishchess.org/tests/view/5f2d22ec61e3b6af64881f40
LLR: 2.94 (-2.94,2.94) {-0.50,1.50}
Total: 17984 W: 2603 L: 2441 D: 12940
Ptnml(0-2): 133, 1751, 5094, 1849, 165

LTC https://tests.stockfishchess.org/tests/view/5f2d5a6a61e3b6af64881f7f
LLR: 2.95 (-2.94,2.94) {0.25,1.75}
Total: 85808 W: 5956 L: 5621 D: 74231
Ptnml(0-2): 149, 4748, 32785, 5063, 159

closes https://github.com/official-stockfish/Stockfish/pull/2950

fixes two README.md typos:
fixes https://github.com/official-stockfish/Stockfish/issues/2932

bench: 4022669

22 months agoParallelize Link Time Optimization for GCC, CLANG and MINGW
Guy Vreuls [Sat, 8 Aug 2020 10:45:10 +0000 (12:45 +0200)]
Parallelize Link Time Optimization for GCC, CLANG and MINGW

This patch tries to run multiple LTO threads in parallel, speeding up
the build process of optimized builds if the -j make parameter is used.
This mitigates the longer linking times of optimized builds since the
integration of the NNUE code. Roughly 2x build speedup.

I've tried a similar patch some two years ago but it ran into trouble
with old compiler versions then. Since we're on the C++17 standard now
these old compilers should be obsolete.

closes https://github.com/official-stockfish/Stockfish/pull/2943

No functional change.

22 months agoDo more aggressive futility pruning for captures
Vizvezdenec [Sat, 8 Aug 2020 14:43:41 +0000 (17:43 +0300)]
Do more aggressive futility pruning for captures

This patch lines up with other patches which use better eval to produce more aggressive cutoffs based on static evaluation of position, it allows more aggressive futility pruning for captures - so now we will be producing them with bigger evaluation of position, so more often.

passed STC
https://tests.stockfishchess.org/tests/view/5f2da79e61e3b6af64881fd2
LLR: 3.87 (-2.94,2.94) {-0.50,1.50}
Total: 27256 W: 3809 L: 3593 D: 19854
Ptnml(0-2): 221, 2578, 7830, 2762, 237

passed LTC
https://tests.stockfishchess.org/tests/view/5f2df92061e3b6af64882012
LLR: 4.97 (-2.94,2.94) {0.25,1.75}
Total: 43624 W: 3095 L: 2820 D: 37709
Ptnml(0-2): 66, 2410, 16608, 2639, 89

closes https://github.com/official-stockfish/Stockfish/pull/2946

Bench: 4272280

22 months agoupdate Null Move Pruning parameters
Moez Jellouli [Sat, 8 Aug 2020 10:35:34 +0000 (12:35 +0200)]
update Null Move Pruning parameters

STC: https://tests.stockfishchess.org/tests/view/5f2dc38561e3b6af64881fec
LLR: 2.99 (-2.94,2.94) {-0.50,1.50}
Total: 6120 W: 903 L: 758 D: 4459
Ptnml(0-2): 44, 535, 1775, 644, 62

LTC: https://tests.stockfishchess.org/tests/view/5f2dd55f61e3b6af64882003
LLR: 2.95 (-2.94,2.94) {0.25,1.75}
Total: 7424 W: 577 L: 463 D: 6384
Ptnml(0-2): 16, 375, 2824, 473, 24

closes https://github.com/official-stockfish/Stockfish/pull/2942

bench 4107833

22 months agoRemove unnecessay legality check
mckx00 [Sat, 8 Aug 2020 10:07:07 +0000 (03:07 -0700)]
Remove unnecessay legality check

Possible after the recent reording pos.legal(move) check

https://github.com/official-stockfish/Stockfish/pull/2941

No functional change.

22 months agosimplified and increased threshold to switch between NNUE and classical
U-DESKTOP-3900\Mark [Fri, 7 Aug 2020 23:53:18 +0000 (19:53 -0400)]
simplified and increased threshold to switch between NNUE and classical

STC https://tests.stockfishchess.org/tests/view/5f2deb1661e3b6af6488200f
LLR: 2.96 (-2.94,2.94) {-1.50,0.50}
Total: 10376 W: 1481 L: 1359 D: 7536
Ptnml(0-2): 91, 953, 2981, 1069, 94

LTC: https://tests.stockfishchess.org/html/live_elo.html?5f2e0a0461e3b6af64882019
LLR: 2.99 (-2.94,2.94) {-1.50,0.50}
Total: 5040 W: 375 L: 315 D: 4350
Ptnml(0-2): 7, 263, 1926, 311, 13

closes https://github.com/official-stockfish/Stockfish/pull/2934

Bench: 4067325

22 months agoDo more futility pruning for parent nodes.
Vizvezdenec [Sat, 8 Aug 2020 02:51:26 +0000 (05:51 +0300)]
Do more futility pruning for parent nodes.

This patch increases LMRdepth threshold for futility pruning at parent nodes so it can apply more often.
With radical change to evaluation approach it seems that search is really far from optimal state, especially it parts that use static evaluation of position.

passed STC
https://tests.stockfishchess.org/tests/view/5f2da75661e3b6af64881fd0
LLR: 2.93 (-2.94,2.94) {-0.50,1.50}
Total: 8744 W: 1305 L: 1156 D: 6283
Ptnml(0-2): 75, 789, 2500, 928, 80

passed LTC
https://tests.stockfishchess.org/tests/view/5f2dcb2a61e3b6af64881ff3
LLR: 2.98 (-2.94,2.94) {0.25,1.75}
Total: 17728 W: 1256 L: 1117 D: 15355
Ptnml(0-2): 22, 961, 6774, 1070, 37

Bench: 4067325

22 months agoReintroduce late irreversible move extension
SFisGOD [Fri, 7 Aug 2020 19:45:08 +0000 (03:45 +0800)]
Reintroduce late irreversible move extension

Reintroduce vondele's late irreversible move extension for fortress keeping.
This was removed when we only had classical eval.
Now that we have the NNUE net, it seems that this is useful again.

STC:
LLR: 2.93 (-2.94,2.94) {-0.50,1.50}
Total: 5352 W: 787 L: 653 D: 3912
Ptnml(0-2): 34, 451, 1579, 571, 41
https://tests.stockfishchess.org/tests/view/5f2dc8ad61e3b6af64881ff0

LTC:
LLR: 2.94 (-2.94,2.94) {0.25,1.75}
Total: 14416 W: 1013 L: 891 D: 12512
Ptnml(0-2): 15, 722, 5623, 822, 26
https://tests.stockfishchess.org/tests/view/5f2e0e3661e3b6af6488201e

closes https://github.com/official-stockfish/Stockfish/pull/2936

Bench: 4154696

22 months agoExpand outposts to minors shielded by pawns
Lolligerhans [Fri, 7 Aug 2020 09:24:37 +0000 (11:24 +0200)]
Expand outposts to minors shielded by pawns

Allow any pawn in front of a minor piece to replace the pawn protection
requirement for outposts.

  +-------+  +-------+
  | . . o |  | o . . |    o  Their pawns
  | . o x |  | o . . |    x  Our pawns
  | o N . |  | x o B |  N,B  New (reachable) outpost
  | . . . |  | . _ . |    _  Reachable square behind a pawn
  +-------+  +-------+
  N outpost  B reaches
               outpost

  We want outposts to be secured by pawns against major pieces. If
a minor is shielded by any pawn from above, it is rarely at the same
time protected by our pawn attacks from below. However, the pawn shield
in itself offers some degree of protection.
  A pawn shield will now suffice to replace the pawn protection for the
outpost (and reachable outpost) bonus.

This effect stacks with the existing "minor behind pawn" bonus.

STC
https://tests.stockfishchess.org/tests/view/5f2bcd14b3ebe5cbfee85b2c
LLR: 2.94 (-2.94,2.94) {-0.50,1.50}
Total: 27248 W: 5353 L: 5119 D: 16776
Ptnml(0-2): 462, 3174, 6185, 3274, 529

LTC
https://tests.stockfishchess.org/tests/view/5f2bfef5b3ebe5cbfee85b5a
LLR: 2.96 (-2.94,2.94) {0.25,1.75}
Total: 99432 W: 12580 L: 12130 D: 74722
Ptnml(0-2): 696, 8903, 30049, 9391, 677

Closes #2935

Bench: 4143673

22 months agoTweak futility pruning depth.
Unai Corzo [Sat, 8 Aug 2020 06:24:20 +0000 (08:24 +0200)]
Tweak futility pruning depth.

STC https://tests.stockfishchess.org/tests/view/5f2d237161e3b6af64881f43
LLR: 2.96 (-2.94,2.94) {-0.50,1.50}
Total: 12712 W: 1823 L: 1664 D: 9225
Ptnml(0-2): 122, 1166, 3627, 1313, 128

LTC https://tests.stockfishchess.org/tests/view/5f2d473061e3b6af64881f6f
LLR: 2.96 (-2.94,2.94) {0.25,1.75}
Total: 12104 W: 912 L: 788 D: 10404
Ptnml(0-2): 13, 665, 4582, 769, 23

closes https://github.com/official-stockfish/Stockfish/pull/2930

bench: 4271421

22 months agoUpdate default net to nn-9931db908a9b.nnue
Sergio Vieri [Fri, 7 Aug 2020 07:15:04 +0000 (15:15 +0800)]
Update default net to nn-9931db908a9b.nnue

Net created at 20200806-1802

passed STC:
https://tests.stockfishchess.org/tests/view/5f2d00b461e3b6af64881f21
LLR: 2.94 (-2.94,2.94) {-0.50,1.50}
Total: 6672 W: 1052 L: 898 D: 4722
Ptnml(0-2): 63, 600, 1868, 730, 75

passed LTC:
https://tests.stockfishchess.org/tests/view/5f2d052a61e3b6af64881f29
LLR: 2.96 (-2.94,2.94) {0.25,1.75}
Total: 7576 W: 573 L: 463 D: 6540
Ptnml(0-2): 8, 392, 2889, 480, 19

closes https://github.com/official-stockfish/Stockfish/pull/2923

Bench: 4390086

22 months agoDo move legality check before pruning.
Stefan Geschwentner [Wed, 5 Aug 2020 07:29:27 +0000 (09:29 +0200)]
Do move legality check before pruning.

This alllows to simplify the code because the move counter haven't to be
decremented later if a move isn't legal. As a side effect now illegal
pruned moves doesn't included anymore in move counter. So slightly less
pruning and reductions are done.

STC:
LLR: 2.94 (-2.94,2.94) {-1.50,0.50}
Total: 111016 W: 21106 L: 21077 D: 68833
Ptnml(0-2): 1830, 13083, 25736, 12946, 1913
https://tests.stockfishchess.org/tests/view/5f28816fa5abc164f05e4c26

LTC:
LLR: 2.94 (-2.94,2.94) {-1.50,0.50}
Total: 39264 W: 4909 L: 4843 D: 29512
Ptnml(0-2): 263, 3601, 11854, 3635, 279
https://tests.stockfishchess.org/tests/view/5f297902a5abc164f05e4c8e

closes https://github.com/official-stockfish/Stockfish/pull/2906

Bench: 4390086

22 months agoRemove QueenInfiltration
UnaiCorzo [Tue, 4 Aug 2020 12:32:52 +0000 (14:32 +0200)]
Remove QueenInfiltration

STC https://tests.stockfishchess.org/tests/view/5f2955b1a5abc164f05e4c85
LLR: 2.96 (-2.94,2.94) {-1.50,0.50}
Total: 29216 W: 5560 L: 5416 D: 18240
Ptnml(0-2): 466, 3329, 6902, 3417, 494

LTC https://tests.stockfishchess.org/tests/view/5f299154a5abc164f05e4ca1
LLR: 2.92 (-2.94,2.94) {-1.50,0.50}
Total: 54144 W: 6635 L: 6594 D: 40915
Ptnml(0-2): 372, 4859, 16536, 4966, 339

closes https://github.com/official-stockfish/Stockfish/pull/2910

Bench: 4609008

22 months agoTuned pawn values
FauziAkram [Fri, 7 Aug 2020 00:37:54 +0000 (17:37 -0700)]
Tuned pawn values

Passed STC:
https://tests.stockfishchess.org/tests/view/5f2aa49fa5abc164f05e4d1b
LLR: 2.95 (-2.94,2.94) {-0.50,1.50}
Total: 40888 W: 7977 L: 7726 D: 25185
Ptnml(0-2): 665, 4806, 9333, 4893, 747

Passed LTC:
https://tests.stockfishchess.org/tests/view/5f2b1059b3ebe5cbfee85ae7
LLR: 2.98 (-2.94,2.94) {0.25,1.75}
Total: 51264 W: 6445 L: 6134 D: 38685
Ptnml(0-2): 328, 4564, 15580, 4789, 371

closes https://github.com/official-stockfish/Stockfish/pull/2920

bench: 4314943

22 months agoAdd tempo also to NNUE eval.
Stefan Geschwentner [Thu, 6 Aug 2020 23:08:15 +0000 (01:08 +0200)]
Add tempo also to NNUE eval.

STC:
LLR: 2.93 (-2.94,2.94) {-0.50,1.50}
Total: 10608 W: 1507 L: 1358 D: 7743
Ptnml(0-2): 94, 945, 3074, 1100, 91
https://tests.stockfishchess.org/tests/view/5f2c5921b3ebe5cbfee85b8b

LTC:
LLR: 2.94 (-2.94,2.94) {0.25,1.75}
Total: 7536 W: 556 L: 448 D: 6532
Ptnml(0-2): 9, 383, 2881, 481, 14
https://tests.stockfishchess.org/tests/view/5f2c6f4461e3b6af64881e95

closes https://github.com/official-stockfish/Stockfish/pull/2919

Bench: 4746616

22 months agoNNUE evaluation threshold
MJZ1977 [Thu, 6 Aug 2020 15:39:10 +0000 (17:39 +0200)]
NNUE evaluation threshold

The idea is to use NNUE only on quite balanced material positions. This bring a big speedup on research since NNUE eval is slower than classical eval for most of the hardwares and specially on unbalanced positions with LazyEval.

STC: https://tests.stockfishchess.org/tests/view/5f2c2680b3ebe5cbfee85b61
LLR: 2.95 (-2.94,2.94) {-0.50,1.50}
Total: 3168 W: 560 L: 400 D: 2208
Ptnml(0-2): 21, 294, 819, 404, 46

LTC: https://tests.stockfishchess.org/tests/view/5f2c2ca6b3ebe5cbfee85b69
LLR: 2.98 (-2.94,2.94) {0.25,1.75}
Total: 3200 W: 287 L: 183 D: 2730
Ptnml(0-2): 4, 149, 1191, 251, 5

closes https://github.com/official-stockfish/Stockfish/pull/2916

Bench 4746616

22 months agoAdd NNUE evaluation
nodchip [Wed, 5 Aug 2020 15:11:15 +0000 (17:11 +0200)]
Add NNUE evaluation

This patch ports the efficiently updatable neural network (NNUE) evaluation to Stockfish.

Both the NNUE and the classical evaluations are available, and can be used to
assign a value to a position that is later used in alpha-beta (PVS) search to find the
best move. The classical evaluation computes this value as a function of various chess
concepts, handcrafted by experts, tested and tuned using fishtest. The NNUE evaluation
computes this value with a neural network based on basic inputs. The network is optimized
and trained on the evalutions of millions of positions at moderate search depth.

The NNUE evaluation was first introduced in shogi, and ported to Stockfish afterward.
It can be evaluated efficiently on CPUs, and exploits the fact that only parts
of the neural network need to be updated after a typical chess move.
[The nodchip repository](https://github.com/nodchip/Stockfish) provides additional
tools to train and develop the NNUE networks.

This patch is the result of contributions of various authors, from various communities,
including: nodchip, ynasu87, yaneurao (initial port and NNUE authors), domschl, FireFather,
rqs, xXH4CKST3RXx, tttak, zz4032, joergoster, mstembera, nguyenpham, erbsenzaehler,
dorzechowski, and vondele.

This new evaluation needed various changes to fishtest and the corresponding infrastructure,
for which tomtor, ppigazzini, noobpwnftw, daylen, and vondele are gratefully acknowledged.

The first networks have been provided by gekkehenker and sergiovieri, with the latter
net (nn-97f742aaefcd.nnue) being the current default.

The evaluation function can be selected at run time with the `Use NNUE` (true/false) UCI option,
provided the `EvalFile` option points the the network file (depending on the GUI, with full path).

The performance of the NNUE evaluation relative to the classical evaluation depends somewhat on
the hardware, and is expected to improve quickly, but is currently on > 80 Elo on fishtest:

60000 @ 10+0.1 th 1
https://tests.stockfishchess.org/tests/view/5f28fe6ea5abc164f05e4c4c
ELO: 92.77 +-2.1 (95%) LOS: 100.0%
Total: 60000 W: 24193 L: 8543 D: 27264
Ptnml(0-2): 609, 3850, 9708, 10948, 4885

40000 @ 20+0.2 th 8
https://tests.stockfishchess.org/tests/view/5f290229a5abc164f05e4c58
ELO: 89.47 +-2.0 (95%) LOS: 100.0%
Total: 40000 W: 12756 L: 2677 D: 24567
Ptnml(0-2): 74, 1583, 8550, 7776, 2017

At the same time, the impact on the classical evaluation remains minimal, causing no significant
regression:

sprt @ 10+0.1 th 1
https://tests.stockfishchess.org/tests/view/5f2906a2a5abc164f05e4c5b
LLR: 2.94 (-2.94,2.94) {-6.00,-4.00}
Total: 34936 W: 6502 L: 6825 D: 21609
Ptnml(0-2): 571, 4082, 8434, 3861, 520

sprt @ 60+0.6 th 1
https://tests.stockfishchess.org/tests/view/5f2906cfa5abc164f05e4c5d
LLR: 2.93 (-2.94,2.94) {-6.00,-4.00}
Total: 10088 W: 1232 L: 1265 D: 7591
Ptnml(0-2): 49, 914, 3170, 843, 68

The needed networks can be found at https://tests.stockfishchess.org/nns
It is recommended to use the default one as indicated by the `EvalFile` UCI option.

Guidelines for testing new nets can be found at
https://github.com/glinscott/fishtest/wiki/Creating-my-first-test#nnue-net-tests

Integration has been discussed in various issues:
https://github.com/official-stockfish/Stockfish/issues/2823
https://github.com/official-stockfish/Stockfish/issues/2728

The integration branch will be closed after the merge:
https://github.com/official-stockfish/Stockfish/pull/2825
https://github.com/official-stockfish/Stockfish/tree/nnue-player-wip

closes https://github.com/official-stockfish/Stockfish/pull/2912

This will be an exciting time for computer chess, looking forward to seeing the evolution of
this approach.

Bench: 4746616

22 months agoTweak cutnode reduction
Stefan Geschwentner [Thu, 30 Jul 2020 16:56:11 +0000 (18:56 +0200)]
Tweak cutnode reduction

Less reduction for second move at non-check CUT node with depth <= 10.

STC:
LLR: 2.94 (-2.94,2.94) {-0.50,1.50}
Total: 38680 W: 7490 L: 7245 D: 23945
Ptnml(0-2): 643, 4441, 8967, 4606, 683
https://tests.stockfishchess.org/tests/view/5f21e1782f7e63962b99f451

LTC:
LLR: 2.95 (-2.94,2.94) {0.25,1.75}
Total: 71976 W: 9003 L: 8636 D: 54337
Ptnml(0-2): 440, 6414, 21972, 6663, 499
https://tests.stockfishchess.org/tests/view/5f2245762f7e63962b99f4bd

closes https://github.com/official-stockfish/Stockfish/pull/2868

Bench: 4746616

22 months agoImprove handling of queen imbalance
Stéphane Nicolet [Tue, 28 Jul 2020 08:08:09 +0000 (10:08 +0200)]
Improve handling of queen imbalance

We double the bonus for potential threats by minors and rooks against
our queen, in case of "queen vs pieces imbalance". Hopefully this will
improve a little bit the evaluation for this well-known Stockfish weakness.

passed STC:
LLR: 2.93 (-2.94,2.94) {-0.50,1.50}
Total: 72976 W: 14003 L: 13710 D: 45263
Ptnml(0-2): 1218, 8370, 17094, 8513, 1293
https://tests.stockfishchess.org/tests/view/5efa50eb020eec13834a977d

passed LTC:
LLR: 2.93 (-2.94,2.94) {0.25,1.75}
Total: 22232 W: 2779 L: 2560 D: 16893
Ptnml(0-2): 129, 1885, 6896, 2050, 156
https://tests.stockfishchess.org/tests/view/5f1fdd2dc09435d870cb9f13

closes https://github.com/official-stockfish/Stockfish/pull/2864

Bench: 4367349

22 months agoRemove late irreversible move extension
UnaiCorzo [Sat, 25 Jul 2020 20:30:05 +0000 (22:30 +0200)]
Remove late irreversible move extension

We simplify away the late irreversible move extension, which
does not seem to be necessary in the current master.

STC
LLR: 2.93 (-2.94,2.94) {-1.50,0.50}
Total: 38584 W: 7464 L: 7342 D: 23778
Ptnml(0-2): 581, 4328, 9365, 4424, 594
https://tests.stockfishchess.org/tests/view/5f1c9669c09435d870cb9de9

LTC
LLR: 2.94 (-2.94,2.94) {-1.50,0.50}
Total: 27840 W: 3417 L: 3353 D: 21070
Ptnml(0-2): 120, 2315, 8994, 2363, 128
https://tests.stockfishchess.org/tests/view/5f1d2e22c09435d870cb9e21

closes https://github.com/official-stockfish/Stockfish/pull/2836

bench: 4829420

22 months agoRemove conditional_more_than_two().
protonspring [Sat, 25 Jul 2020 13:32:19 +0000 (07:32 -0600)]
Remove conditional_more_than_two().

This is a functional simplification that removes the conditional_more_than_two()
function, which was quite strange and kooky. Note the very minor change to the bench
value.

See this thread for relevant comments on the passing branch:
protonspring/Stockfish@d89730d...ff35b50

STC
LLR: 2.95 (-2.94,2.94) {-1.50,0.50}
Total: 59760 W: 11411 L: 11311 D: 37038
Ptnml(0-2): 992, 6863, 14044, 7015, 966
https://tests.stockfishchess.org/tests/view/5f179988c09435d870cb9b9a

LTC
LLR: 2.93 (-2.94,2.94) {-1.50,0.50}
Total: 45208 W: 5553 L: 5497 D: 34158
Ptnml(0-2): 315, 4081, 13761, 4127, 320
https://tests.stockfishchess.org/tests/view/5f184847c09435d870cb9bee

closes https://github.com/official-stockfish/Stockfish/pull/2826

Bench: 4578290

23 months agoDo not overwrite valuable TT data after probcut.
Vizvezdenec [Mon, 13 Jul 2020 17:30:58 +0000 (20:30 +0300)]
Do not overwrite valuable TT data after probcut.

This patch allows an engine to write probcut data only in case
the probcut search depth is greater than transposition table depth.

passed STC
https://tests.stockfishchess.org/tests/view/5f0b52e959f6f035328949a6
LLR: 2.97 (-2.94,2.94) {-0.50,1.50}
Total: 52544 W: 10145 L: 9880 D: 32519
Ptnml(0-2): 853, 6097, 12121, 6334, 867

passed LTC
https://tests.stockfishchess.org/tests/view/5f0bd94c59f6f035328949f3
LLR: 2.93 (-2.94,2.94) {0.25,1.75}
Total: 49576 W: 6164 L: 5863 D: 37549
Ptnml(0-2): 297, 4371, 15218, 4538, 364

closes https://github.com/official-stockfish/Stockfish/pull/2815

bench 4578298

23 months agoMultiple lazy stages.
mstembera [Sun, 12 Jul 2020 20:58:00 +0000 (13:58 -0700)]
Multiple lazy stages.

An extension of the lazy eval idea: when the score is sufficiently large
we now skip more granular parts of the eval.

Inspired by an original patch by Moez Jellouli
https://tests.stockfishchess.org/tests/view/5f03b2a159f6f03532894529
Credit to him!

STC https://tests.stockfishchess.org/tests/view/5f0a862c59f6f03532894924
LLR: 2.95 (-2.94,2.94) {-0.50,1.50}
Total: 13504 W: 2684 L: 2472 D: 8348
Ptnml(0-2): 229, 1496, 3111, 1666, 250

LTC https://tests.stockfishchess.org/tests/view/5f0ac0e159f6f0353289495b
LLR: 2.94 (-2.94,2.94) {0.25,1.75}
Total: 31312 W: 3926 L: 3677 D: 23709
Ptnml(0-2): 185, 2773, 9509, 2986, 203

closes https://github.com/official-stockfish/Stockfish/pull/2814

bench: 4541608

23 months agoCorrects a functional change in a cleanup patch.
syzygy1 [Sat, 11 Jul 2020 14:25:34 +0000 (16:25 +0200)]
Corrects a functional change in a cleanup patch.

This corrects a functional change in
https://github.com/official-stockfish/Stockfish/commit/ddcbacd04d1c860e808202ce8c1206c8acdca627
changing evaluation of KPPvK. Bench remains unchanged at low depth

With this patch, 8/8/5k1p/8/7p/7K/8/8 b - - 1 11 is again correctly evaluated as a draw.

closes https://github.com/official-stockfish/Stockfish/pull/2807

Bench: 4366686

23 months agoIntroduce bad outpost penalty
SFisGOD [Wed, 8 Jul 2020 02:09:32 +0000 (10:09 +0800)]
Introduce bad outpost penalty

In some French games, Stockfish likes to bring the Knight to a bad outpost spot. This is evident in TCEC S18 Superfinal Game 63, where there is a Knight outpost on the queenside but is actually useless. Stockfish is effectively playing a piece down while holding ground against Leela's break on the kingside.

This patch turns the +56 mg bonus for a Knight outpost into a -7 mg penalty if it satisfies the following conditions:

* The outpost square is not on the CenterFiles (i.e. not on files C,D,E and F)
* The knight is not attacking non pawn enemies.
* The side where the outpost is located contains only few enemies, with a particular conditional_more_than_two() implementation

Thank you to apospa...@gmail.com for bringing this to our attention and for providing insights.
See https://groups.google.com/forum/?fromgroups=#!topic/fishcooking/dEXNzSIBgZU
Reference game: https://tcec-chess.com/#div=sf&game=63&season=18

Passed STC:
LLR: 2.93 (-2.94,2.94) {-0.50,1.50}
Total: 6960 W: 1454 L: 1247 D: 4259
Ptnml(0-2): 115, 739, 1610, 856, 160
https://tests.stockfishchess.org/tests/view/5f08221059f6f0353289477e

Passed LTC:
LLR: 2.98 (-2.94,2.94) {0.25,1.75}
Total: 21440 W: 2767 L: 2543 D: 16130
Ptnml(0-2): 122, 1904, 6462, 2092, 140
https://tests.stockfishchess.org/tests/view/5f0838ed59f6f035328947a2

various related tests show strong test results, but so far no generalizations or simplifications of conditional_more_than_two() are found. See PR for details.

closes https://github.com/official-stockfish/Stockfish/pull/2803

Bench: 4366686

23 months agoMaximize usage of transposition table in probcut
Vizvezdenec [Fri, 10 Jul 2020 21:06:55 +0000 (00:06 +0300)]
Maximize usage of transposition table in probcut

Probcut is a heuristic that wasn't changed a lot in past years,
all attempts to change it using information / writing info to transposition table failed.

This patch has a number of differences that can be summarized as follows:

* For TT write/read we use depth - 3. Because probcut search is depth - 4 but we actually do the move prior to it so effectively we do depth - 3 search;
* In any case of depth of eval from transposition table being >= depth - 3 we either produce cutoff or refuse to even do probcut search, this is allowing us to write info of probcut to transposition table because we know that we wouldn't be overwriting some deeper data with our depth - 3 search - this is an important aspect of this patch;
* For some not really known reason this patch completely ignores tte->bound() - which was the case for previous patch that made probcut interact with TT, maybe 2) is the reason, although it's unproven.

A first version of this patch passed STC and LTC

passed STC
https://tests.stockfishchess.org/tests/view/5f05908a59f6f03532894613
LLR: 2.95 (-2.94,2.94) {-0.50,1.50}
Total: 95776 W: 18300 L: 17973 D: 59503
Ptnml(0-2): 1646, 10944, 22377, 11279, 1642

passed LTC
https://tests.stockfishchess.org/tests/view/5f06b54059f6f035328946bb
LLR: 2.94 (-2.94,2.94) {0.25,1.75}
Total: 57128 W: 7266 L: 6938 D: 42924
Ptnml(0-2): 372, 5163, 17217, 5389, 423

However, an additional bugfix was needed to avoid checking a condition on ttMove if was not available. This passed non-regression bounds on top of the first version:

at STC
https://tests.stockfishchess.org/tests/view/5f080e5059f6f03532894766
LLR: 2.94 (-2.94,2.94) {-1.50,0.50}
Total: 14096 W: 2800 L: 2628 D: 8668
Ptnml(0-2): 225, 1620, 3238, 1688, 277

at LTC
https://tests.stockfishchess.org/tests/view/5f0836a559f6f0353289479c
LLR: 2.95 (-2.94,2.94) {-1.50,0.50}
Total: 25352 W: 3228 L: 3139 D: 18985
Ptnml(0-2): 175, 2350, 7549, 2415, 187

closes https://github.com/official-stockfish/Stockfish/pull/2804

Bench 4540940

23 months agoSmall cleanups
Joost VandeVondele [Thu, 9 Jul 2020 20:01:06 +0000 (22:01 +0200)]
Small cleanups

closes https://github.com/official-stockfish/Stockfish/pull/2772

No functional change

23 months agoSimplify make_promotions()
mstembera [Sun, 5 Jul 2020 22:17:04 +0000 (15:17 -0700)]
Simplify make_promotions()

Remove special case handling of QUIET_CHECKS in make_promotions()

STC https://tests.stockfishchess.org/tests/view/5f055dbb59f6f035328945fb
LLR: 2.98 (-2.94,2.94) {-1.50,0.50}
Total: 42808 W: 8177 L: 8054 D: 26577
Ptnml(0-2): 665, 4890, 10201, 4953, 695

LTC https://tests.stockfishchess.org/tests/view/5f06231a59f6f03532894661
LLR: 2.96 (-2.94,2.94) {-1.50,0.50}
Total: 9616 W: 1214 L: 1111 D: 7291
Ptnml(0-2): 53, 821, 2965, 908, 61

closes https://github.com/official-stockfish/Stockfish/pull/2800

Bench: 4576410

23 months agoConnected / blocked pawns simplification
FauziAkram [Tue, 7 Jul 2020 22:29:03 +0000 (01:29 +0300)]
Connected / blocked pawns simplification

There is no need to score blocked pawns at many places.
The idea originated from: Rocky
Tuning and testing by: Fauzi

Passed STC:
https://tests.stockfishchess.org/tests/view/5f04f8fd59f6f035328945d4
LLR: 2.94 (-2.94,2.94) {-1.50,0.50}
Total: 6352 W: 1299 L: 1118 D: 3935
Ptnml(0-2): 89, 695, 1469, 792, 131

Passed LTC:
https://tests.stockfishchess.org/tests/view/5f0527bd59f6f035328945e3
LLR: 2.94 (-2.94,2.94) {-1.50,0.50}
Total: 27648 W: 3517 L: 3433 D: 20698
Ptnml(0-2): 177, 2561, 8301, 2571, 214

closes https://github.com/official-stockfish/Stockfish/pull/2799

Bench: 4734746

23 months agoClean-up en passant processing
Alain SAVARD [Tue, 7 Jul 2020 02:43:54 +0000 (22:43 -0400)]
Clean-up en passant processing

the goal of this PR is to better document how we process
the ep square (if any) given position fen command, and to
output more meaningful (and consistent) debug fen on the "d"
command. The implementation follows
https://en.wikipedia.org/wiki/X-FEN#Encoding_en-passant
following x-fen, it is "valid" to record ep even if ep would put king en prise.

fixes #2784

closes https://github.com/official-stockfish/Stockfish/pull/2797

No functional change