Now "Write Search Log" will pring moves in UCI format, consistent with all the rest. This functionality is
not aimed at end-users anyway. It's hardly useful at all, in fact. Also, pretty-printing SAN moves is
something that better belongs in the GUI than in the engine.
No functional change.
Where they better belong.
Also, this removes '#include <string>' from types.h, which reduces the amount of code to compile (every
translation unit includes types.h).
No functional change.
Unify various perft functions and move all the code
to search.cpp.
Avoid perft implementation to be splitted between
benchmark.cpp (where it has no reason to be) and
search.cpp
No functional and no speed change (tested).
So that one can redirect cout to /dev/null and only print print cerr in the terminal (for more accurate speed
tests).
Suggested by Marco.
No functional change.
The compiler tries to cast Options["Hash"] into a string, using:
Option::operator std::string() const {
assert(type == "string");
return currentValue;
}
And, as expected, the assert() fails.
std::to_string() would be the right solution, but it's C++11. And using a stringstream is too much code to
achieve so little. Let's keep it the way it was: hardcoded (ie. default hash defined in two places).
No functional change.
The eval already returns zero in KK, KBK, KNK (see material.cpp). The difference is:
- we lose the "TB pruning" benefit of the draw rule (ie. search goes on even if eval is zero)
- we gain some speed by removing a useless test from the hot path
STC:
LLR: 0.05 (-2.94,2.94) [-3.00,1.00]
Total: 128000 W: 21357 L: 21560 D: 85083
LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 33023 W: 4613 L: 4509 D: 23901
bench 7461881
First, remove some dead code (function never called with a Move argument).
Then, remove printing of legal moves, which does not belong here. Let's keep commands orthogonal and minimal:
- the "d" command should display the board, nothing more, or less.
- "perft 1" will display the list of legal moves.
No functional change.
Stockfish allocates the default hash (32MB) in main(), before entering UCI::loop(). If there is not enough
memory, the program will crash even before UCI::loop() is entered and the GUI is given a change to specify a
lower Hash value.
This defective design could be resolved by doing a lazy allocation upon "isready" command, as the UCI protocol
guarantees that "isready" will be sent at least once before any search. But it's a bit cumbersome when using
Stockfish "manually" to have to remember to type "isready" everytime.
So leave the current design, but reduce the default hash to 16MB instread of 32MB. In order to perform such
quick searches (depth=13), there is no reason to use so much Hash anyway. Another benefit is to introduce a
bit of hash pressure in bench, which increases chances to detect rare bugs related to TT replacement, for
example.
This is not a functional change, although it obviously changes the bench.
bench 7461879
Instead of defining it both in ucioption.cpp and benchmark.cpp. Obviously changing the default Hash will
change the bench as a result.
No functional change.
The main purpose of perft is to help debugging. But without the breakdown in sum of perft(N-1), it is a
completely useless debugging tool.
So perft now displays the breakdown, and divide is therefore removed.
No functional change.
After commit 94b1bbb68b, in case available root moves are less than multiPV, we
could never reach condition:
PVIdx + 1 == multiPV
and as a consequence UCI output is not printed.
Fixed suggested by Joerg Oster.
No functional change.
Despite being neutral at STC, it turned out to be regressive at LTC:
40k games at LTC with Hash=8
ELO: -2.06 +-1.9 (95%) LOS: 1.4%
Total: 39720 W: 5740 L: 5976 D: 28004
40k games at LTC with Hash=128
ELO: -2.69 +-1.9 (95%) LOS: 0.2%
Total: 39149 W: 5702 L: 6005 D: 27442
bench 7477963
Also raise the admissible bounds to (-100,100), as there is no reason to prevent users from using high
values if they want to.
Does not regress in self play:
ELO: 0.10 +-2.0 (95%) LOS: 53.7%
Total: 40000 W: 7084 L: 7073 D: 25843
master vs SF 3
ELO: 182.86 +-2.7 (95%) LOS: 100.0%
Total: 40000 W: 21843 L: 2541 D: 15616
Contempt = 20 vs SF 3
ELO: 189.25 +-2.8 (95%) LOS: 100.0%
Total: 40000 W: 22721 L: 2859 D: 14420
Diff is therefore 6.4 +/- 3.9 elo against a 180-190 elo weaker engine, which is significantly positive,
as expected. This elo difference is likely understated, because of FishTest aggressive draw adjudication
though.
We could push Contempt further, but after 20cp, it would get in the way of FishTest draw adjudication
rule, and is likely to reduce the testing throughput as a result.
bench 8198667
Steamline a bit the implementation of
skill levels. As a side effect we can
retire MultiPV global and use a local
variable instead.
No functional change.
- Currently broken
- Never been really useful
- Does not work well with new splitting model
Verified for no regression at STC with 3 threads:
LLR: 2.96 (-2.94,2.94) [-6.00,0.00]
Total: 81905 W: 12122 L: 12381 D: 57402
No functional change
Bitboard init code is already noteasy to follow,
so don't make it even harder using 'smart' code.
Also reindent a while loop in standard way.
No functional change.
With Eelco's patch "Don't special case for abs(beta) >= VALUE_MATE_IN_MAX_PLY" condition "abs(ttValue) < VALUE_KNOWN_WIN" has been removed from singular extension search, and condition "abs(beta) < VALUE_KNOWN_WIN" was added to the SingularExtensionNode definition.
This might lead to problems, especially in positions, where a mate is due.
For example, this position 5rk1/4K1pp/8/5PPP/8/8/8/1R6 w - - 12 1 triggers an assert.
stockfish: search.cpp:434: Value {anonymous}::search(Position&, Search::Stack*, Value, Value, Depth, bool) [with {anonymous}::NodeType NT = (<unnamed>::NodeType)2u; bool SpNode = false]: Assertion `-VALUE_INFINITE <= alpha && alpha < beta && beta <= VALUE_INFINITE' failed.
So let's re-insert the removed condition.
First spotted by Uri Blass, fix by me.
Bench: 8759675
* /boot/common was removed from Haiku
* The equivalent path now that package management has been implemented is /boot/system/non-packaged
No functional change
Bench: 8759681
The assert:
assert(ttValue != VALUE_NONE);
Could fire for multiple reasons (although is very rare),
for instance after an IID we can have ttMove != MOVE_NONE
while ttValue is still set at VALUE_NONE.
But not only this, actually SMP is a source of corrupted
ttValue and anyhow we can detect the condition:
ttMove != MOVE_NONE && ttValue == VALUE_NONE
even north of IID.
Reported by Ronald de Man.
It is so rare that bench didn't change.
bench: 7710548
