Allow to use EvalInfo struct, populated by
evaluation(), in search.
In particular we allocate Eval::Info on the stack
and pass a pointer to this to evaluate().
Also add to Search::Stack a pointer to Eval::Info,
this allows to reference eval info of previous/next
nodes.
WARNING: Eval::Info is NOT initialized and is populated
by evaluate(), only if the latter is called, and this
does not happen in all the code paths, so care should be
taken when accessing this struct.
No functional change.
And return on using TT as backing store for position
evaluations.
Tests (even on single thread) show eval cache was a regression.
In multi thread result should be even worst because eval cache
is a per-thread struct, while TT is shared.
After 4957 games at 15"+0.05 (single thread)
eval cache vs master 969 - 1093 - 2895 -9 ELO
So previous reported result of +18 ELO was probably due to an
issue in the testing framework (a bug in cutechess-cli) that
has been fixed in the meanwhile.
bench: 5386711
With this patch series we want to introduce a per-thread
evaluation cache to store node evaluation and do not
rely anymore on the TT table for this.
This patch just introduces the infrastructure.
No functional change.
First disable Contempt Factor during analysis, then
calculate the modified draw score from the point of
view of the player, so from the point of view of
RootPosition color.
Thanks to Ryan Taker for suggesting the fixes.
No functional change.
This is very crude and very basic: simply in case
of a draw for repetition or 50 moves rule return
a negative score instead of zero according to the
contempt factor (in centipawns). If contempt is
positive engine will try to avoid draws (to use
with weaker opponents), if negative engine will
try to draw. If zero (default) there are no changes.
No functional change.
So to be done only once at startup and in the (unlikely)
cases that a relevant UCI parameter is changed, instead
of doing it at the beginning of each search.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This change allows to remove some quite a bit of code
and seems the natural thing to do.
Introduced file thread.cpp to move away from search.cpp a lot
of threads related stuff.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This patch is based on Justin Blanchard's original
work and allows to breakdown evaluation in its sub terms and
show to the user.
Tracing code has zero speed impact when not used.
Note that tracing code is not thread-safe, but this
should not be a problem given the typical usage scenario.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This is the "selective search depth in plies" and we set
equal to PV line length.
Tested that works under FritzGUI.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Currently are used by evaluation itself and the
whole EvalInfo will be removed from global visibility
by next patch, so no reason to use them.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It will be more clear when we will go to add stuff
apart from king danger itself.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Get it from the position instead.
A good semplification of function calling and a speedup too.
No functional change also with faked split.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Remove a lot of complex, obscure and useless code.
After 999 games at 1+0
Mod vs Orig +162 =673 -164 -1 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This is what actually is.
A standard naming convention suggests to name a variable
with someting resembling _what_ the variable is and not
_how_ the variable is used. This normally results
in easier to read code.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Use a Weights[] array instead of named variables to
store evaluation weights.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This is less prone to bugs because now it's up to the
compiler don't forget this important initialization.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
No change in functionality signature
The only functional change is that when we reach PLY_MAX,
we now return VALUE_DRAW instead of evaluating position.
But we reach PLY_MAX only when position is dead drawn and
transposition table is filled with draw scores, so this
shouldn't matter at all.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Save mid and end game scores in an union so to
operate on both values in one instruction.
This patch just introduces the infrastructure and changes
EvalInfo to use a single Score value instead of mgValue
and egValue.
Speed is more or less the same because we still don't use
unified midgame-endgame tables where the single assignment
optimization can prove effective.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Prune more moves after a null search because of
a lower beta limit then in main search.
In test positions reduces the searched nodes of 30% !!!!
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
There are subtle differences in the king evaluation
that should be clear to avoid misunderstandings.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
