Some renaming in MovePicker

No functional change.
Small touches in move generation

No functional change.
Better condition in is_pseudo_legal()

Simplify occupied destination condition.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Use arrow operator instead of * and .

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Tune pawn PSQT values

Reduces the influence of PSQT for entries such as
the extended center and the h-file.

Passed both short TC test:
LLR: 2.95 (-2.94,2.94)
Total: 23919 W: 5207 L: 5029 D: 13683

And long TC one:
LLR: 2.96 (-2.94,2.94)
Total: 5762 W: 1108 L: 974 D: 3680

Bench: 4617880

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Revert "Halve king eval margin"

This reverts commit 4b3a0fdab03a7529ede42891963d3036712a0bd5.

As Gary says: " It failed when I tried it at long TC previously, and only
barely passed this time.  Some anecdotal evidence is that it hurts vs other
engines as well (the Lightspeed rating list showed a 16 elo drop from previous
best version - still +- 5 error bars on both, but that's still significant)"

I also agree that if we have some doubts (like in this case) it is better to
be safe than sorry.

bench: 4615572
Simplify captures ordering

A big simplification and removing of useless code.

Finished at 50% both at short TC (with SPRT) than
at long TC at fixed number of games:
ELO: -0.14 +-3.4 (95%) LOS: 46.8%
Total: 15206 W: 2836 L: 2842 D: 9528

bench: 5059948
Use #ifndef instead of #if !defined

And #ifdef instead of #if defined

This is more standard form (see for example iostream file).

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Fix a typo in bitboard.h

Introduced by previous patch.

Spotted by Joerg Oster

No functional change.
Rewrite pawn shield and storm code

Passes quickly both short TC:
LLR: 2.95 (-2.94,2.94)
Total: 5755 W: 1349 L: 1222 D: 3184

And long TC:
LLR: 2.95 (-2.94,2.94)
Total: 2744 W: 628 L: 505 D: 1611

bench: 4727133