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.
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/2823https://github.com/official-stockfish/Stockfish/issues/2728
The integration branch will be closed after the merge:
https://github.com/official-stockfish/Stockfish/pull/2825https://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
Fixes a few merge conflicts.
Verified equal bench for 1 rank, and expected performance master vs cluster with 2 ranks.
Score of cluster vs master: 196 - 54 - 400 [0.609] 650
Elo difference: 77.1 +/- 16.3, LOS: 100.0 %, DrawRatio: 61.5 %
No functional change.
* Supports popcnt (thanks @daylen)
* bits = 64 is now the default
Tested with g++ (Ubuntu/Linaro 7.5.0-3ubuntu1~18.04) 7.5.0 on ThunderX CN8890,
yields about 9% speedup.
Also tested with clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final).
closes https://github.com/official-stockfish/Stockfish/pull/2770
No functional change.
fixes https://github.com/official-stockfish/Stockfish/issues/2660
The problem was caused by .depend being created with a rule for tbprobe.o not for syzygy/tbprobe.o.
This patch keeps an explicit list of sources (SRCS), generates OBJS,
and compiles all object files to the src/ directory, consistent with .depend.
VPATH is used to search the syzygy directory as needed.
joint work with @gvreuls
closes https://github.com/official-stockfish/Stockfish/pull/2664
No functional change
The purpose of the code is to allow developers to easily and flexibly
setup SF for a tuning session. Mainly you have just to remove 'const'
qualifiers from the variables you want to tune and flag them for
tuning, so if you have:
int myKing = 10;
Score myBonus = S(5, 15);
Value myValue[][2] = { { V(100), V(20) }, { V(7), V(78) } };
and at the end of the update you may want to call
a post update function:
void my_post_update();
If instead of default Option's min-max values,
you prefer your custom ones, returned by:
std::pair<int, int> my_range(int value)
Or you jus want to set the range directly, you can
simply add below:
TUNE(SetRange(my_range), myKing, SetRange(-200, 200), myBonus, myValue, my_post_update);
And all the magic happens :-)
At startup all the parameters are printed in a
format suitable to be copy-pasted in fishtest.
In case the post update function is slow and you have many
parameters to tune, you can add:
UPDATE_ON_LAST();
And the values update, including post update function call, will
be done only once, after the engine receives the last UCI option.
The last option is the one defined and created as the last one, so
this assumes that the GUI sends the options in the same order in
which have been defined.
closes https://github.com/official-stockfish/Stockfish/pull/2654
No functional change.
- Cleanups by Alain
- Group king attacks and king defenses
- Signature of futility_move_count()
- Use is_discovery_check_on_king()
- Simplify backward definition
- Use static asserts in move generator
- Factor a statement in move generator
No functional change
Follow-up to previous commit. Update the documentation for the user when using `make`,
to show the preferred bmi2 compile in the advanced examples section.
Note: I made a mistake in the previous commit comment, the documentation is shown when
using `make` or `make help`, not `make --help`.
No functional change
The only change done to the Makefile to get a somewhat faster binary as
discussed in #2291 is to add -msse4 to the compile options of the bmi2 build.
Since all processors supporting bmi2 also support sse4 this can be done easily.
It is a useful step to avoid sending around custom and poorly tested builds.
The speedup isn't enough to pass [0,4] but it is roughly 1.15Elo and a LOS of 90%:
LLR: -2.95 (-2.94,2.94) [0.00,4.00]
Total: 93009 W: 20519 L: 20316 D: 52174
Also rewrite the documentation for the user when using `make --help`, so that
the order of architectures for x86-64 has the more performant build one on top.
Closes https://github.com/official-stockfish/Stockfish/pull/2300
No functional change
PowerPC has had popcount instructions for a long time, at least as far
back as POWER5 (released 2004). Enable them via a gcc builtin.
Using a gcc builtin has the added bonus that if compiled for a processor
that lacks a hardware instruction, gcc will include a software popcount
implementation that does not use the instruction. It might be slower
than the table lookups (or it might be faster) but it will certainly work.
So this isn't going to break anything.
On my POWER8 VM, this leads to a ~4.27% speedup.
Fir prefetch, the gcc builtin generates a 'dcbt' instruction, which is
supported at least as far back as the G5 (2002) and POWER4 (2001).
This leads to a ~5% speedup on my POWER8 VM.
No functional change
This generalizes exchange of signals between the ranks using a non-blocking all-reduce. It is now used for the stop signal and the node count, but should be easily generalizable (TB hits, and ponder still missing). It avoids having long-lived outstanding non-blocking collectives (removes an early posted Ibarrier). A bit too short a test, but not worse than before:
Score of new-r4-1t vs old-r4-1t: 459 - 401 - 1505 [0.512] 2365
Elo difference: 8.52 +/- 8.43
avoid saving to TT the part of the receive buffer that actually originates from the same rank.
Now, on 1 mpi rank, we have the same bench as the non-mpi code on 1 thread.
In the original code, the position key stored in the TT is used to probe&store TT entries after message passing. Since we only store part of the bits in the TT, this leads to incorrect rehashing. This is fixed in this patch storing also the full key in the send buffers, and using that for hashing after message arrival.
Short testing with 4 ranks (old vs new) shows this is effective:
Score of mpiold vs mpinew: 84 - 275 - 265 [0.347] 624
Elo difference: -109.87 +/- 20.88
Based on Peter Österlund's "Lazy Cluster" algorithm,
but with some simplifications.
To compile, point COMPCXX to the MPI C++ compiler wrapper (mpicxx).
Preparation commit for the upcoming Stockfish 10 version, giving a chance to catch last minute feature bugs and evaluation regression during the one-week code freeze period. Also changing the copyright dates to include 2019.
No functional change
Currently the make strip target is broken on mingw as the exe name is wrong (stockfish instead of stockfish.exe).
Needs some testing by mingw users (both profile-build and strip, native and cross).
No functional change.
Apply -mdynamic-no-pic in a single place in the Makefile instead of 5 places.
Verified on three different Macs:
- a MacBook from 2013
- a MacBook running MacOS 10.9.5
- an iMac running MacOS 10.13.3
No functional change.
Enable link-time optimization in the Makefile when compiling with clang.
Also update travis.yml to use clang++-5.0 and llvm-5.0-dev.
No functional change.
Add the -fno-exceptions flag to the Makefile to avoid the unecessary exceptions support in the executable (we do not use any exception in Stockfish at the moment).
This change gives a 9.2% reduction in size for the executable binary.
Before : executable size = 376956 bytes
After: executable size = 347652 bytes
No functional change.
In light of issue #1232, a test was performed about the value of '-fno-exceptions' and a second one of the combination '-fno-exceptions -fno-rtti'. It turns out these options are can be removed without introducing slowdown.
STC for removing '-fno-exceptions'
LLR: 2.94 (-2.94,2.94) [-3.00,1.00]
Total: 13678 W: 2572 L: 2439 D: 8667
STC for removing '-fno-exceptions -fno-rtti' (current patch)
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 32557 W: 6074 L: 5973 D: 20510
No functional change.
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
the nodes, tbHits, rootDepth and lastInfoTime variables are read by multiple threads, but not declared atomic, leading to data races as found by -fsanitize=thread. This patch fixes this issue. It is based on top of the CI-threading branch (PR #1129), and should fix the corresponding CI error messages.
The patch passed an STC check for no regression:
http://tests.stockfishchess.org/tests/view/5925d5590ebc59035df34b9f
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 169597 W: 29938 L: 30066 D: 109593
Whereas rootDepth and lastInfoTime are not performance critical, nodes and tbHits are. Indeed, an earlier version using relaxed atomic updates on the latter two variables failed STC testing (http://tests.stockfishchess.org/tests/view/592001700ebc59035df34924), which can be shown to be due to x86-32 (http://tests.stockfishchess.org/tests/view/592330ac0ebc59035df34a89). Indeed, the latter have no instruction to atomically update a 64bit variable. The proposed solution thus uses a variable in Position that is accessed only by one thread, which is copied every few thousand nodes to the shared variable in Thread.
No functional change.
Closes#1130Closes#1129
Fixes failing build for
make ARCH=x86-32 clean && make ARCH=x86-32 optimize=no build
by passing -m32 also to the link step.
Extend travis testing accordingly.
No functional change.
Closes#999
This refines the profile-build target to avoid 'touch'ing the sources,
keeping meaningful modification dates and avoiding editor warnings like vi's:
WARNING: The file has been changed since reading it!!!
Do you really want to write to it (y/n)?
Instead of touching sources, the (instrumented) object files are removed,
which has the same effect of rebuilding them in the next step.
As a side effect, this simplifies the Makefile a bit.
No functional change.
Small fixes for compilation with sanitize=yes optimize=no,
by always adding -fsanitize=undefined to the LDFLAGS as required.
Updates config-sanity to check&report the status of the flag.
No functional change.
Joost VandeVondele