We disjoint pseudo legal detection from full legal detection.
It will be used by future patches.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Use Square instead. At the end is the same because we were
anyway foreseen operators on mixed terms (Square, SquareDelta).
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
MSVC (and possibly other compilers) does not inline
as requested, so force it to do so.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Move the castling condition test out of the
function. This avoids a function call most of
the times.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Functional change due only to moves reorder. Anyhow after
5242 games at 15"+0.1 TC verified we have no regression.
Mod vs Orig 994 - 958 - 3290 +2 ELO
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We must be able to filter out also moves where move_is_ok()
is false.
And actually we are. Tested on all the default position injecting
a number from -1000000 to 1000000 casted to a Move.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Should be already inlined by the compiler when
optimizing but better safe than sorry ;-)
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This patch greatly cleanups generation of pawn moves but
we change the order in which moves are generated so there is
a change in functionality, but not in perft.
The only real functionality change is that now when type == CHECK
we generate knight underpromotion captures only if give check and
not always as before.
Perft is 2% faster and fully verified.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Mostly suggested by Justin (UncombedCoconut), the 0ULL -> 0 conversion
is mine.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Instead of one comparison in while() condition use two,
the first to check if the piece is exsistant and the second
to loop across pieces of that type.
This should help branch prediction in cases we have only
one piece of the same type, for instance for queens, the
first branch is always true and the second is almost always
false.
Increased speed of 0.3-0.5 % on Gcc pgo compiles.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We don't need to generate captures and non
captures in a separate step. This gives another
7% push to perft speed.
yes, I know, it is totally useless :-)
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It is now no more needed to know dc candidates
inside MovePicker, so avoid calculating there.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Big cleanup and semplification of pawns evasions that
now are pseudo-legal as the remaining moves. This
allow us to remove a lot of tricky code.
Verified against perft: no functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This allow a big semplification in move generation
that will be committed with the next patch. And makes
handling of evasions similar to the other type of moves.
This patch plus the next seem to improve also on
the performance side because after 640 games to
verify there are no hidden regressions we are at +9 ELO
Verified with perft no functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Generate captures of checking piece and blocking
evasions in one go.
Also reduce of one indentation level early returning
when we have a double check.
Verified with perft no functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Check generation is used only in qsearch and
only at Depth(0), castling moves that give check
are very rare overall and even almost not exsistent
at Depth(0).
So retire this almost never used code that adds
a small but consistent slow down in the normal path.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Because discovery checks are very rare it is better to handle
them all in one go and strip from usual check generation
function.
Also rewrite direct checks generation to use piece lists instead
of pop_1st_bit()
On perft test we have a +6% of speed up and is verified we
generate the same moves, although in a different order.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This patch make the piece list always terminated by SQ_NONE,
so that we can use a simpler and faster loop in move
generation.
Speedup is about 0.6%.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
A better and more specific name. Also a bit of code reshuffle.
Verified No functional change and No performance change
for the whole series.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Rewrite in the form normally used in other similar
functions like generate_pawn_noncaptures()
This allow an easier reading of the pawn moves generators
and simplify a bit the code.
No functional change (tested on more then 100M nodes).
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
A bunch of trivial code style and comment fixes.
Among them there is a real fix for a subtle case
involving promotion moves.
We currently check that a pawn push to 8/1th rank
must be a promotion, but we don't check the contary,
i.e. that a pawn push on a different rank must NOT be
a promotion. Note that, funny enough, we perform this
control for all the other pieces, but not for the pawns!
This patch fixes this really corner case.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Remove a bunch of difficult and tricky code to test
legality of castle and ep moves and instead use a slower
but simpler check against the list of generated legal moves.
Because these moves are very rare the performance impact
is small but code semplification is ver big: almost 100 lines
of difficult code removed !
No functionality change. No performance change (strangely enough
there is no even minimal performance regression in pgo builds but
instead a slightly and unexpected increase).
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
In qsearch at depth 0 we generate only captures and checks.
Queen promotion moves are generated among the captures, but
under-promotion moves (both captures and non-captures) are
never generated even if they could give a discovery check.
This patch fixes this limitation extending generate_pawn_noncaptures()
to generate also check moves when required.
Apart for adding the (rare) case of an under-promotion that gives
discovery check, the patch is also a good cleanup because removes
generate_pawn_checks() altoghter.
This patch does the code clean-up but not enables the functional
change so to allow an easier debug.
No functional change and no performance change (actually a very
very small speed increase).
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
