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Reformat promotion generation
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Use the same template of other pawns moves generation,
make the code more uniform, simplify generate_promotions
that has now been renamed.

No functional change (verified also with perft).
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@mcostalba
mcostalba committed Dec 25, 2014
1 parent 296534f commit 2bfacf1
Showing 1 changed file with 42 additions and 42 deletions.
84 changes: 42 additions & 42 deletions src/movegen.cpp
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Expand Up @@ -66,33 +66,25 @@ namespace {


template<GenType Type, Square Delta>
inline ExtMove* generate_promotions(ExtMove* moveList, Bitboard pawnsOn7,
Bitboard target, const CheckInfo* ci) {
inline ExtMove* make_promotions(ExtMove* moveList, Square to, const CheckInfo* ci) {

Bitboard b = shift_bb<Delta>(pawnsOn7) & target;
if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
(moveList++)->move = make<PROMOTION>(to - Delta, to, QUEEN);

while (b)
if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
{
Square to = pop_lsb(&b);

if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
(moveList++)->move = make<PROMOTION>(to - Delta, to, QUEEN);

if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
{
(moveList++)->move = make<PROMOTION>(to - Delta, to, ROOK);
(moveList++)->move = make<PROMOTION>(to - Delta, to, BISHOP);
(moveList++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
}

// Knight promotion is the only promotion that can give a direct check
// that's not already included in the queen promotion.
if (Type == QUIET_CHECKS && (StepAttacksBB[W_KNIGHT][to] & ci->ksq))
(moveList++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
else
(void)ci; // Silence a warning under MSVC
(moveList++)->move = make<PROMOTION>(to - Delta, to, ROOK);
(moveList++)->move = make<PROMOTION>(to - Delta, to, BISHOP);
(moveList++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
}

// Knight promotion is the only promotion that can give a direct check
// that's not already included in the queen promotion.
if (Type == QUIET_CHECKS && (StepAttacksBB[W_KNIGHT][to] & ci->ksq))
(moveList++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
else
(void)ci; // Silence a warning under MSVC

return moveList;
}

Expand All @@ -111,7 +103,7 @@ namespace {
const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW);
const Square Left = (Us == WHITE ? DELTA_NW : DELTA_SE);

Bitboard b1, b2, dc1, dc2, emptySquares;
Bitboard emptySquares;

Bitboard pawnsOn7 = pos.pieces(Us, PAWN) & TRank7BB;
Bitboard pawnsNotOn7 = pos.pieces(Us, PAWN) & ~TRank7BB;
Expand All @@ -124,8 +116,8 @@ namespace {
{
emptySquares = (Type == QUIETS || Type == QUIET_CHECKS ? target : ~pos.pieces());

b1 = shift_bb<Up>(pawnsNotOn7) & emptySquares;
b2 = shift_bb<Up>(b1 & TRank3BB) & emptySquares;
Bitboard b1 = shift_bb<Up>(pawnsNotOn7) & emptySquares;
Bitboard b2 = shift_bb<Up>(b1 & TRank3BB) & emptySquares;

if (Type == EVASIONS) // Consider only blocking squares
{
Expand All @@ -144,8 +136,8 @@ namespace {
// promotion has been already generated amongst the captures.
if (pawnsNotOn7 & ci->dcCandidates)
{
dc1 = shift_bb<Up>(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
dc2 = shift_bb<Up>(dc1 & TRank3BB) & emptySquares;
Bitboard dc1 = shift_bb<Up>(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
Bitboard dc2 = shift_bb<Up>(dc1 & TRank3BB) & emptySquares;

b1 |= dc1;
b2 |= dc2;
Expand Down Expand Up @@ -174,16 +166,25 @@ namespace {
if (Type == EVASIONS)
emptySquares &= target;

moveList = generate_promotions<Type, Right>(moveList, pawnsOn7, enemies, ci);
moveList = generate_promotions<Type, Left >(moveList, pawnsOn7, enemies, ci);
moveList = generate_promotions<Type, Up>(moveList, pawnsOn7, emptySquares, ci);
Bitboard b1 = shift_bb<Right>(pawnsOn7) & enemies;
Bitboard b2 = shift_bb<Left >(pawnsOn7) & enemies;
Bitboard b3 = shift_bb<Up >(pawnsOn7) & emptySquares;

while (b1)
moveList = make_promotions<Type, Right>(moveList, pop_lsb(&b1), ci);

while (b2)
moveList = make_promotions<Type, Left >(moveList, pop_lsb(&b2), ci);

while (b3)
moveList = make_promotions<Type, Up >(moveList, pop_lsb(&b3), ci);
}

// Standard and en-passant captures
if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
{
b1 = shift_bb<Right>(pawnsNotOn7) & enemies;
b2 = shift_bb<Left >(pawnsNotOn7) & enemies;
Bitboard b1 = shift_bb<Right>(pawnsNotOn7) & enemies;
Bitboard b2 = shift_bb<Left >(pawnsNotOn7) & enemies;

while (b1)
{
Expand Down Expand Up @@ -290,7 +291,6 @@ namespace {
return moveList;
}


} // namespace


Expand All @@ -311,9 +311,9 @@ ExtMove* generate(const Position& pos, ExtMove* moveList) {

Color us = pos.side_to_move();

Bitboard target = Type == CAPTURES ? pos.pieces(~us)
: Type == QUIETS ? ~pos.pieces()
: Type == NON_EVASIONS ? ~pos.pieces(us) : 0;
Bitboard target = Type == CAPTURES ? pos.pieces(~us)
: Type == QUIETS ? ~pos.pieces()
: Type == NON_EVASIONS ? ~pos.pieces(us) : 0;

return us == WHITE ? generate_all<WHITE, Type>(pos, moveList, target)
: generate_all<BLACK, Type>(pos, moveList, target);
Expand Down Expand Up @@ -401,18 +401,18 @@ ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* moveList) {
template<>
ExtMove* generate<LEGAL>(const Position& pos, ExtMove* moveList) {

ExtMove *end, *cur = moveList;
Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
Square ksq = pos.king_square(pos.side_to_move());
ExtMove* cur = moveList;

end = pos.checkers() ? generate<EVASIONS>(pos, moveList)
: generate<NON_EVASIONS>(pos, moveList);
while (cur != end)
moveList = pos.checkers() ? generate<EVASIONS >(pos, moveList)
: generate<NON_EVASIONS>(pos, moveList);
while (cur != moveList)
if ( (pinned || from_sq(cur->move) == ksq || type_of(cur->move) == ENPASSANT)
&& !pos.legal(cur->move, pinned))
cur->move = (--end)->move;
cur->move = (--moveList)->move;
else
++cur;

return end;
return moveList;
}

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