Add support for Mac clang compiler

Makefile modified to support the clang compiler under Mac.
This was tested using clang 4 under Mountain Lion, but should
also work fine under Lion and possibly under Snow Leopard.

It requires the 'Xcode 4.x Command Line Tools' to be installed.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Remove unreachable extension condition

A PvNode that givesCheck has been already granted
an extension of ONE_PLY in previous condition.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Increase optimization level of Clang

Set optimization level to 4 and get a 2.564% faster binary:

Stockfish (Clang, Level 4) bench:
$ make build ARCH=osx-x86-64 COMP=clang
(Clang does not support PGO)
Average of 4 trials:
Total time (ms): 5137.5
Nodes searched: 5631135
Nodes/second: 1096084.5

Stockfish (Clang, Level 3) bench:
$ make build ARCH=osx-x86-64 COMP=clang
(Clang does not support PGO)
Average of 4 trials:
Total time (ms): 5269.25
Nodes searched: 5631135
Nodes/second: 1068679.25

Stockfish (GCC, PGO) bench:
$ make profile-build ARCH=osx-x86-64
Average of 4 trials:
Total time (ms): 5286
Nodes searched: 5631135
Nodes/second: 1065292.25

Suggestion and performance tests by Daylen Yang.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Don't split if reduced depth is below min_split_depth

It seems to increase SMP performances. To note that
this patch goes in the opposite direction of "Active
reparenting" where we try to reparent an idle slave
as soon as possible. Instead here we prefer to keep
it idle instead of splitting on a shallow / near the
leaves node.

After 11550 games on a QUAD (4 threads) at 15"+0.05
Mod vs Orig 1972 - 1752 - 7826 ELO +6 (+-3.6)

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Convert constants to decimal representation

Hex representation doesn't add any value in those cases.
Preserve hex representation where more self-documenting
for instance for binary masks values.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Change pos.pieces() argument order

Let first argument to be the 'color'. This allows to align
pos.pieces() signatures with piece_list(), piece_count() and
all the other functions where 'color' argument is passed as
first one.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Simplify attacks_bb()

And some formatting while there.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Fix compilation with Android NDK

It seems ADL lookup is broken with the STLPort library. Peter says:

The compiler is gcc 4.4.3, but I don't know how many patches they
have applied to it. I think gcc has had support for Koenig lookup
a long time. I think the problem is the type of the vector iterator.
For example, line 272 in search.cpp:

 if (bookMove && count(RootMoves.begin(), RootMoves.end(), bookMove))

gives the error:

jni/stockfish/search.cpp:272: error: 'count' was not declared in this scope

Here RootMoves is:

 std::vector<RootMove> RootMoves;

If std::vector<T>::iterator is implemented as T*, then Koenig lookup
would fail because RootMove* is not in namespace std.

I compile with the stlport implementation of STL, which in its vector
class has:

 typedef value_type* iterator;

I'm not sure if this is allowed by the C++ standard. I did not find
anything that says the iterator type must belong to namespace std.
The consensus in this thread

http://compgroups.net/comp.lang.c++.moderated/argument-dependent-lookup/433395

is that the stlport iterator type is allowed.

Report and patch by Peter Osterlund.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Junior promotion patch

Assumption: Junior sends promotions according to the side to move (ucase/lcase).
Fact: Stockfish generally handles promotion lcase.
Patch: Handling position fen input moves always with lcase promotions.

Ported back by Portfish. No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Improve previous patch

Only in case of promotion we care about an upper case
promotion piece char, so std::transform() is overkill
for the task.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Revert "Don't split if reduced below min_split_depth"

After extensive testing (I was off line this week and let
the test go on) it seems this change is useless:

After 33968 games on a QUAD (4 threads) at 15"+0.05
Mod vs Orig 5425 - 5550 - 22993 ELO -1 (+-2.1)

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Simplify Position::print()

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Add a known draw case in kpk bitbase generation

Early classify as known draws the positions
where white king is trapped on the rook file.

Suggested by Dan Honeycutt.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Redefine enum CastleRight

To be aligned with PolyGlot book castle right definitions.

This will be used by next patch.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Fix book file regression

Revision 2aac860db3d04881103a3b0d0 of 27 / 4 / 2012
changed can_castle() signatures from bool to int and
this broke the code that calculates polyglot hash key
in book.cpp

Instead of directly fixing the code we prefer to change
castling rights definitions to align to the polyglot ones
(as we did in previous patch). After this step we can simply
take internal castle rights as they are and use them
directly to calculate polyglot book hash key, as we do
in this patch that fixes the regression.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Rename psq_score in ReducedStateInfo

So to be fully in sync with StateInfo, and move struct
to position.h, just below StateInfo.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Fix a possible 'Division by zero'

In case a book entry has 'count' field set to 0
we crash. Spotted by Clang's static analyzer.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Retire PieceOffset[] in book.cpp

And calculate piece offset on the fly. Also
improve comments.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Fix an issue when adding a book during the game

Currently when we fail to open a book file, for instance
if it doesn't exsist, we leave Book::open() with ifstream
failbit set. If then the book file is added, we correctly
open it at next attempt, but failbit is still set so that
after opening we exit because ifstream::good() returns false.

The fix is to reset failbit upon exiting.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Fix a compile error in opposite_colors()

Error is due to ambiguous overloading of operator^
because we have both the built-in operator^(int, int)
and the user defined operator^(Bitboard, Square).

This error does not trigger when using Makefile becuase,
due to luck, the user defined operator^(Bitboard, Square)
happens to be always defined _after_ opposite_colors() so
that compiler does not claim. But in case of Microsoft MSVC
we don't have a Makefile and the order of files compilation
is chosen by the compiler (in an unpredictable way). So it
could still happen that error is not detected (as in my case),
but in another case the order of compilation of the files could
be so that at some point both operator^ were defined before
opposite_colors() and this triggers the error.

The fix is much simpler than the explanation :-)

Reported by Quocvuong82.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>