Revert all the patches that introduced the change and
more or less fixed the zugzwang issue.
There is a gain against last current version and we
can remove a lot of code.
After 979 games at 1+0 on my QUAD
Mod vs Orig +152 =688 -139 +5 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This is the world's fussiest compiler with +w1
Warnings reported by Richard Lloyd.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Add VALUE_TYPE_NS_LO to enum ValueType and use it when
saving in TT a value from a null search.
Currently no action is performed, the next patch will enable
the new type.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Louis Zulli reports a miscompile with g++-4.4 from MacPorts.
Namely enum Value is compiled as unsigned instead of signed integer
and this yields an issue in score_string() where float(v) is incorrectly
casted when Value v is negative.
This patch ensure that compiler choses a signed variable to store a Value.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
According to the standard, compiler is free to choose
the enum type as long as can keep its data.
Also cast to short and right shift are implementation
defined in case of a signed integer.
Normally all the compilers implement this stuff in
the "usual" way, but gcc with -O3 and -O2 pushes
aggressively the language to its limits to squeeze
even the last bit of speed. And this broke our
not 100% standard conforming code.
The fix is to rewrite the Score enum and the 16 bits
word extracting functions in a way that is 100% standard
compliant and with no speed regression on gcc and also on
the other compilers.
Verified it works on all compilers and with equivalent
functionality.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
The compiler is allowed to chose the size of an enum variable
based on the values it is expected to store. So force the compiler
to use at least a 32 bit integer type for the Score.
MSVC and Intel do not change, while gcc under -O3 is affected
by this change.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Increases performance because now we use one integer
for both midgame and endgame scores.
Unfortunatly the latest patches seem to have reduced a bit
the speed so at the end we are more or less at the same
performance level of the beginning. But this patch series
introduced also some code cleanup so it is the main reason
we commit anyway.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Instead of MgPieceSquareTable[16][64] and EgPieceSquareTable[16][64]
This allows to fetch mg and eg values from adjacent words in memory.
No functional change.
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>
When a node fails low and bestValue is still equal to
the original static node evaluation, then save this
in TT along with usual info.
This will allow us to avoid a future costly evaluation() call.
This patch extends to failed low nodes what we already do
for failed high ones.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
There were two asserts.
The first was raised because is_ok() was called at the
beginning of do_castle_move() and this is wrong after
the last code reformatting because at that point the state
is already modified by the caller do_move().
The second, raised by debugIncrementalEval, was due to a
rounding error in compute_value() that occurs because
TempoValueEndgame was updated in an odd number by patch
"Merge Joona Kiiski evaluation tweaks" (3ed603cd) of 13/3/2009
This line in compute_value() is the guilty one:
result += (side_to_move() == WHITE)? TempoValue / 2 : -TempoValue / 2;
The fix is to increment TempoValueEndgame so to be even.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Unfortunatly this tweak does not give good results.
After 894 games at 1+0 we have:
Mod vs Orig +205/-236/=453 48.27% -12 ELO !!
Perhaps we should test again, but in the mean time
we are going to revert this.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This is the backport of tuned piece values.
We needed to change also the psqt tables so that their
values, that are relative to piece values, remain the same.
Amost no change after 999 games:
Mod vs Orig 594-495 + 2 ELO points so well within error bar
It was expected somehow given the very little change of the
parameters values.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This also allow us to better track what is already
optimized and what still needs optimization.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Instead of just drop evaluation score after stand pat
logic save it in TT so to be reused if the same position
occurs again.
Note that we NEVER use the cached value apart to avoid an
evaluation call, in particulary we never return to caller
after a succesful tt hit.
To accomodate this a new value type VALUE_TYPE_EVAL has been
introduced so that ok_to_use_TT() always returns false.
With this patch we cut about 15% of total evaluation calls.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
