phalanx = neighbours & rank_bb(s);
supported = neighbours & rank_bb(s - Up);
- // A pawn is backward when it is behind all pawns of the same color on the
- // adjacent files and cannot be safely advanced.
- if (!neighbours || lever || relative_rank(Us, s) >= RANK_5)
- backward = false;
- else
- {
- // Find the backmost rank with neighbours or stoppers
- b = rank_bb(backmost_sq(Us, neighbours | stoppers));
-
- // The pawn is backward when it cannot safely progress to that rank:
- // either there is a stopper in the way on this rank, or there is a
- // stopper on adjacent file which controls the way to that rank.
- backward = (b | shift<Up>(b & adjacent_files_bb(f))) & stoppers;
-
- assert(!(backward && (forward_ranks_bb(Them, s + Up) & neighbours)));
- }
+ // A pawn is backward when it is behind all pawns of the same color
+ // on the adjacent files and cannot be safely advanced.
+ backward = !(ourPawns & pawn_attack_span(Them, s + Up))
+ && (stoppers & (leverPush | (s + Up)));
// Passed pawns will be properly scored in evaluation because we need
// full attack info to evaluate them. Include also not passed pawns
void init() {
- static constexpr int Seed[RANK_NB] = { 0, 13, 24, 18, 76, 100, 175, 330 };
+ static constexpr int Seed[RANK_NB] = { 0, 13, 24, 18, 65, 100, 175, 330 };
for (int opposed = 0; opposed <= 1; ++opposed)
for (int phalanx = 0; phalanx <= 1; ++phalanx)
Value safety = (ourPawns & file_bb(ksq)) ? Value(5) : Value(-5);
- if ((shift<Down>(theirPawns) & (FileABB | FileHBB) & BlockRanks) & ksq)
+ if (shift<Down>(theirPawns) & (FileABB | FileHBB) & BlockRanks & ksq)
safety += 374;
File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));