Now that we use spinlocks everywhere and don't put
threads to sleep while idle, we can use the slower
(but no more in hot path) std::condition_variable_any
instead of our homwgrown ConditionVariable struct.
Verified fo rno regression at STC with 7 threads:
ELO: -0.66 +-2.7 (95%) LOS: 31.8%
Total: 20000 W: 3210 L: 3248 D: 13542
No functional change
There's no reason to define it as a Bitboard, so for consistency, use bool.
This is even a speedup on my machine: i7-3770k, using gcc 4.9.1 (linux):
stat test master diff
mean 2,341,338 2,327,998 13,134
stdev 15,765 14,717 5,405
speedup 0.56%
P(speedup>0) 100.0%
No functional change.
Resolves#298
Avoid redundant 'while' conditions. It is enough to
check them in the outer loop.
Quick tested for no regression 10K games at 4 threads
ELO: -1.32 +-3.9 (95%) LOS: 25.6%
Total: 10000 W: 1653 L: 1691 D: 6656
No functional change.
Spinlock must be used instead.
Tested for no regression at 15+0.05 th 4:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 25928 W: 4303 L: 4190 D: 17435
No functional change.
Resolves#297
Unify the quites moves loop for both cases,
the compiler optimizes away the
if (is_ok((ss-1)->currentMove))
inside loop, so that the result is same
speed as original.
No functional change.
During the search, do not block on condition variable, but instead use std::this_thread::yield().
Clear gain with 16 threads. Again results vary highly depending on hardware, but on average it's a clear gain.
ELO: 12.17 +-4.3 (95%) LOS: 100.0%
Total: 7998 W: 1407 L: 1127 D: 5464
There is no functional change in single thread mode
Resolves#294
Both are the result of a SPSA tuning session with a custom book, 50k iterations each.
After an additional tuning session of the mobility values, tuning the delta values, with following result.
40k games at 9+0.05:
ELO: 4.13 +-2.2 (95%) LOS: 100.0%
Total: 40000 W: 8581 L: 8106 D: 23313
and LTC
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 36518 W: 6049 L: 5782 D: 24687
Bench: 8567402
Resolves#284
Fixes reported startup error about missing libwinpthread-1.dll
when the dll is not in the path.
The current -static-xxxx flags, introduced with:
https://github.com/official-stockfish/Stockfish/commit/373503f4a9a990054b5
Only take in account standard libraries, but not thread
library.
No functional change.
Resolves#289
Idea and original implementation by Stephane Nicolet
7 threads 15+0.05
ELO: 3.54 +-2.9 (95%) LOS: 99.2%
Total: 17971 W: 2976 L: 2793 D: 12202
There is no functional change in single thread mode
Spend much less time in positions where one move is much better than all other alternatives.
We carry forward pv stability information from the previous search to identify such positions.
It's based on my old InstaMove idea but with two significant improvements.
1) Much better instability detection inside the search itself.
2) When it's time to make a FastMove we no longer make it instantly but still spend at least 10% of normal time verifying it.
Credit to Gull for the inspiration.
BIG thanks to Gary because this would not work without accurate PV!
20K
ELO: 8.22 +-3.0 (95%) LOS: 100.0%
Total: 20000 W: 4203 L: 3730 D: 12067
STC
LLR: 2.96 (-2.94,2.94) [-1.50,4.50]
Total: 23266 W: 4662 L: 4492 D: 14112
LTC
LLR: 2.95 (-2.94,2.94) [0.00,6.00]
Total: 12470 W: 2091 L: 1931 D: 8448
Resolves#283
Introduce a counter move history table which additionally is indexed by the last move's piece and target square.
For quiet move ordering use now the sum of standard and counter move history table.
STC:
LLR: 2.96 (-2.94,2.94) [-1.50,4.50]
Total: 4747 W: 1005 L: 885 D: 2857
LTC:
LLR: 2.95 (-2.94,2.94) [0.00,6.00]
Total: 5726 W: 1001 L: 872 D: 3853
Because of reported low NPS on multi core test
STC (7 threads):
ELO: 7.26 +-3.3 (95%) LOS: 100.0%
Total: 14937 W: 2710 L: 2398 D: 9829
Bench: 7725341
Resolves#282
Use Mutex instead.
This is in preparaation for merging with master branch,
where we stilll don't have spinlocks.
Eventually spinlocks will be readded in some future
patch, once c++11 has been merged.
No functional change.
minKingPawnDistance is used only as local variable in one place so we don't need it to be part of "Pawns::Entry" structure.
No functional change.
Resolves#277
This change in the Makefile restores the possibility to compile
Stockfish on Mac OS X 10.9 and 10.10 after the C++11 has been merged.
To use the default (fastest) settings, compile with:
make build ARCH=x86-64-modern
To test the clang settings, compile with
make build ARCH=x86-64-modern COMP=clang
Beware that the clang settings may provide a slightly slower (6%)
executable.
Backported from master.
No functional change
Resolves#275
This change in the Makefile restores the possibility to compile
Stockfish on Mac OS X 10.9 and 10.10 after the C++11 has been merged.
To use the default (fastest) settings, compile with:
make build ARCH=x86-64-modern
To test the clang settings, compile with
make build ARCH=x86-64-modern COMP=clang
Beware that the clang settings may provide a slightly slower (6%)
executable.
No functional change
Resolves#275
Now that c++11 branch has been merged in master,
disable unconditionally the spinlocks and use mutex
instead. This will allow to run fishtest even on HT
machines withouth changes.
In the future we will reintorduce spinlocks, once
we will have took care of fishtest.
No functional change.
And use mutex instead. You may never want to do this.
It is a workaround to run c++11 on fishtest where many
machiens have HTenabled and this can be a problem when
number of cores set is higher than number of physical cores.
To disable spinlocks, just compile with -DNO_SPINLOCK flag
No functional change.
Calling lock.test_and_set() in a tight loop creates expensive
memory synchronizations among processors and penalize other
running threads. So syncronize only only once at the beginning
with fetch_sub() and then loop on a simple load() that puts much
less pressure on the system.
Reported about 2-3% speed up on various systems.
Patch by Ronald de Man.
No functional change.
It is reported to be defenitly faster with increasing
number of threads, we go from a +3.5% with 4 threads
to a +15% with 16 threads.
The only drawback is that now when testing with more
threads than physical available cores, the speed slows
down to a crawl. This is expected and was similar at what
we had setting the old sleepingThreads to false.
No functional change.
Initialization is more complex than what I'd like due
to MSVC compatibility that for some reason does not like:
std::atomic_flag lock = ATOMIC_FLAG_INIT;
No functional change.
