Assorted trivial cleanups 4/2019

No functional change.

diff --git a/src/bitbase.cpp b/src/bitbase.cpp
index 8c8c47020bb2678d74ddc45628bd87f152e6ff88..2b1a5517fb8152df1809f0f508e082177660fb39 100644 (file)
--- a/src/bitbase.cpp
+++ b/src/bitbase.cpp
@@ -27,7 +27,8 @@
 
 namespace {
 
-  // There are 24 possible pawn squares: the first 4 files and ranks from 2 to 7
+  // There are 24 possible pawn squares: files A to D and ranks from 2 to 7.
+  // Positions with the pawn on files E to H will be mirrored before probing.
   constexpr unsigned MAX_INDEX = 2*24*64*64; // stm * psq * wksq * bksq = 196608
 
   // Each uint32_t stores results of 32 positions, one per bit

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index 0ab244c7acecaa8f2bf108fc5171066f2ea2d3b9..281579c4a621842e312dfe43f7058e6a55fff34e 100644 (file)
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -18,8 +18,8 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <bitset>
 #include <algorithm>
+#include <bitset>
 
 #include "bitboard.h"
 #include "misc.h"
@@ -27,16 +27,10 @@
 uint8_t PopCnt16[1 << 16];
 uint8_t SquareDistance[SQUARE_NB][SQUARE_NB];
 
+Bitboard SquareBB[SQUARE_NB];
 Bitboard LineBB[SQUARE_NB][SQUARE_NB];
 Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
 Bitboard PawnAttacks[COLOR_NB][SQUARE_NB];
-Bitboard SquareBB[SQUARE_NB];
-
-Bitboard KingFlank[FILE_NB] = {
-  QueenSide ^ FileDBB, QueenSide, QueenSide,
-  CenterFiles, CenterFiles,
-  KingSide, KingSide, KingSide ^ FileEBB
-};
 
 Magic RookMagics[SQUARE_NB];
 Magic BishopMagics[SQUARE_NB];

diff --git a/src/bitboard.h b/src/bitboard.h
index 53e96f4455478e176f79b2c98b28799a5e7f6bee..4e0267f11e42efbe192224494b2cb69ab6b4dff2 100644 (file)
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -65,14 +65,19 @@ constexpr Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
 constexpr Bitboard KingSide    = FileEBB | FileFBB | FileGBB | FileHBB;
 constexpr Bitboard Center      = (FileDBB | FileEBB) & (Rank4BB | Rank5BB);
 
+constexpr Bitboard KingFlank[FILE_NB] = {
+  QueenSide ^ FileDBB, QueenSide, QueenSide,
+  CenterFiles, CenterFiles,
+  KingSide, KingSide, KingSide ^ FileEBB
+};
+
 extern uint8_t PopCnt16[1 << 16];
 extern uint8_t SquareDistance[SQUARE_NB][SQUARE_NB];
 
+extern Bitboard SquareBB[SQUARE_NB];
 extern Bitboard LineBB[SQUARE_NB][SQUARE_NB];
 extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
 extern Bitboard PawnAttacks[COLOR_NB][SQUARE_NB];
-extern Bitboard KingFlank[FILE_NB];
-extern Bitboard SquareBB[SQUARE_NB];
 
 
 /// Magic holds all magic bitboards relevant data for a single square
@@ -148,6 +153,7 @@ inline Bitboard file_bb(Square s) {
 template<Direction D>
 constexpr Bitboard shift(Bitboard b) {
   return  D == NORTH      ?  b             << 8 : D == SOUTH      ?  b             >> 8
+        : D == NORTH+NORTH?  b             <<16 : D == SOUTH+SOUTH?  b             >>16
         : D == EAST       ? (b & ~FileHBB) << 1 : D == WEST       ? (b & ~FileABB) >> 1
         : D == NORTH_EAST ? (b & ~FileHBB) << 9 : D == NORTH_WEST ? (b & ~FileABB) << 7
         : D == SOUTH_EAST ? (b & ~FileHBB) >> 7 : D == SOUTH_WEST ? (b & ~FileABB) >> 9
@@ -370,8 +376,8 @@ inline Square pop_lsb(Bitboard* b) {
 }
 
 
-/// frontmost_sq() and backmost_sq() return the square corresponding to the
-/// most/least advanced bit relative to the given color.
+/// frontmost_sq() and backmost_sq() return the most/least advanced square in
+/// the given bitboard relative to the given color.
 
 inline Square frontmost_sq(Color c, Bitboard b) { return c == WHITE ? msb(b) : lsb(b); }
 inline Square  backmost_sq(Color c, Bitboard b) { return c == WHITE ? lsb(b) : msb(b); }

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 7e6260c8a34128fe588b3a2c492e07af526986b1..5750d82a7281bbd9ff91f6b22f137b9e9fac0600 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -18,6 +18,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <algorithm>
 #include <cassert>
 #include <cstring>   // For std::memset
 #include <iomanip>
@@ -186,9 +187,8 @@ namespace {
     // is also calculated is ALL_PIECES.
     Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
 
-    // attackedBy2[color] are the squares attacked by 2 pieces of a given color,
-    // possibly via x-ray or by one pawn and one piece. Diagonal x-ray through
-    // pawn or squares attacked by 2 pawns are not explicitly added.
+    // attackedBy2[color] are the squares attacked by at least 2 units of a given
+    // color, including x-rays. But diagonal x-rays through pawns are not computed.
     Bitboard attackedBy2[COLOR_NB];
 
     // kingRing[color] are the squares adjacent to the king, plus (only for a
@@ -241,8 +241,7 @@ namespace {
     attackedBy[Us][KING] = pos.attacks_from<KING>(ksq);
     attackedBy[Us][PAWN] = pe->pawn_attacks(Us);
     attackedBy[Us][ALL_PIECES] = attackedBy[Us][KING] | attackedBy[Us][PAWN];
-    attackedBy2[Us]            = (attackedBy[Us][KING] & attackedBy[Us][PAWN])
-                                 | dblAttackByPawn;
+    attackedBy2[Us] = dblAttackByPawn | (attackedBy[Us][KING] & attackedBy[Us][PAWN]);
 
     // Init our king safety tables
     kingRing[Us] = attackedBy[Us][KING];
@@ -309,11 +308,11 @@ namespace {
             bb = OutpostRanks & ~pe->pawn_attacks_span(Them);
             if (bb & s)
                 score += Outpost * (Pt == KNIGHT ? 4 : 2)
-                                 * (1 + bool(attackedBy[Us][PAWN] & s));
+                                 * ((attackedBy[Us][PAWN] & s) ? 2 : 1);
 
             else if (bb &= b & ~pos.pieces(Us))
                 score += Outpost * (Pt == KNIGHT ? 2 : 1)
-                                 * (1 + bool(attackedBy[Us][PAWN] & bb));
+                                 * ((attackedBy[Us][PAWN] & bb) ? 2 : 1);
 
             // Knight and Bishop bonus for being right behind a pawn
             if (shift<Down>(pos.pieces(PAWN)) & s)
@@ -358,8 +357,8 @@ namespace {
                 score += RookOnPawn * popcount(pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]);
 
             // Bonus for rook on an open or semi-open file
-            if (pos.semiopen_file(Us, file_of(s)))
-                score += RookOnFile[bool(pos.semiopen_file(Them, file_of(s)))];
+            if (pos.is_semiopen_file(Us, file_of(s)))
+                score += RookOnFile[bool(pos.is_semiopen_file(Them, file_of(s)))];
 
             // Penalty when trapped by the king, even more if the king cannot castle
             else if (mob <= 3)
@@ -672,7 +671,7 @@ namespace {
 
                 bonus += make_score(k * w, k * w);
             }
-        } // rank > RANK_3
+        } // r > RANK_3
 
         // Scale down bonus for candidate passers which need more than one
         // pawn push to become passed, or have a pawn in front of them.
@@ -717,7 +716,7 @@ namespace {
     // Find all squares which are at most three squares behind some friendly pawn
     Bitboard behind = pos.pieces(Us, PAWN);
     behind |= shift<Down>(behind);
-    behind |= shift<Down>(shift<Down>(behind));
+    behind |= shift<Down+Down>(behind);
 
     int bonus = popcount(safe) + popcount(behind & safe);
     int weight =  pos.count<ALL_PIECES>(Us)
@@ -777,8 +776,7 @@ namespace {
     if (sf == SCALE_FACTOR_NORMAL)
     {
         if (   pos.opposite_bishops()
-            && pos.non_pawn_material(WHITE) == BishopValueMg
-            && pos.non_pawn_material(BLACK) == BishopValueMg)
+            && pos.non_pawn_material() == 2 * BishopValueMg)
             sf = 16 + 4 * pe->passed_count();
         else
             sf = std::min(40 + (pos.opposite_bishops() ? 2 : 7) * pos.count<PAWN>(strongSide), sf);

diff --git a/src/misc.cpp b/src/misc.cpp
index 449e07cee9b28530b6c1f646be50043c7a905a33..8d3b202d14df71a21dd42b07005fe709e0bba2f4 100644 (file)
--- a/src/misc.cpp
+++ b/src/misc.cpp
@@ -210,12 +210,6 @@ void prefetch(void* addr) {
 
 #endif
 
-void prefetch2(void* addr) {
-
-  prefetch(addr);
-  prefetch((uint8_t*)addr + 64);
-}
-
 namespace WinProcGroup {
 
 #ifndef _WIN32

diff --git a/src/misc.h b/src/misc.h
index 4b238df549decf27c75768ce7fa8177ddcfaab1e..ddd05e4e13d56dc67a829cbf08bc07504e945505 100644 (file)
--- a/src/misc.h
+++ b/src/misc.h
@@ -31,7 +31,6 @@
 
 const std::string engine_info(bool to_uci = false);
 void prefetch(void* addr);
-void prefetch2(void* addr);
 void start_logger(const std::string& fname);
 
 void dbg_hit_on(bool b);

diff --git a/src/pawns.cpp b/src/pawns.cpp
index 095126d451964942b26b6a79d5118e606d524b31..0a88c9f1ba37b07a3738800fea6d11f0c003ec09 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -18,6 +18,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <algorithm>
 #include <cassert>
 
 #include "bitboard.h"
@@ -175,14 +176,14 @@ Value Entry::evaluate_shelter(const Position& pos, Square ksq) {
 
   constexpr Color     Them = (Us == WHITE ? BLACK : WHITE);
   constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH);
-  constexpr Bitboard  BlockRanks = (Us == WHITE ? Rank1BB | Rank2BB : Rank8BB | Rank7BB);
+  constexpr Bitboard BlockSquares =  (Rank1BB | Rank2BB | Rank7BB | Rank8BB)
+                                   & (FileABB | FileHBB);
 
   Bitboard b = pos.pieces(PAWN) & ~forward_ranks_bb(Them, ksq);
   Bitboard ourPawns = b & pos.pieces(Us);
   Bitboard theirPawns = b & pos.pieces(Them);
 
-  Value safety = (shift<Down>(theirPawns) & (FileABB | FileHBB) & BlockRanks & ksq) ?
-                 Value(374) : Value(5);
+  Value safety = (shift<Down>(theirPawns) & BlockSquares & ksq) ? Value(374) : Value(5);
 
   File center = clamp(file_of(ksq), FILE_B, FILE_G);
   for (File f = File(center - 1); f <= File(center + 1); ++f)

diff --git a/src/pawns.h b/src/pawns.h
index 88b5554537e72a935606d0665a0f1668838f26a4..76c5ffc95100bcf9a4b45a7e788f8d874b55153c 100644 (file)
--- a/src/pawns.h
+++ b/src/pawns.h
@@ -38,7 +38,7 @@ struct Entry {
   Bitboard passed_pawns(Color c) const { return passedPawns[c]; }
   Bitboard pawn_attacks_span(Color c) const { return pawnAttacksSpan[c]; }
   int weak_unopposed(Color c) const { return weakUnopposed[c]; }
-  int passed_count() const { return popcount(passedPawns[WHITE] | passedPawns[BLACK]); };
+  int passed_count() const { return popcount(passedPawns[WHITE] | passedPawns[BLACK]); }
 
   template<Color Us>
   Score king_safety(const Position& pos) {

diff --git a/src/position.cpp b/src/position.cpp
index ada03fbcf4b1076b38d5aca3583d5bf5b60be2f7..8c6dc8023af52997b2dac142c5fcb454a07ed314 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -18,6 +18,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <algorithm>
 #include <cassert>
 #include <cstddef> // For offsetof()
 #include <cstring> // For std::memset, std::memcmp
@@ -340,8 +341,8 @@ void Position::set_castling_right(Color c, Square rfrom) {
   Square kto = relative_square(c, cs == KING_SIDE ? SQ_G1 : SQ_C1);
   Square rto = relative_square(c, cs == KING_SIDE ? SQ_F1 : SQ_D1);
 
-  castlingPath[cr] = (between_bb(rfrom, rto) | between_bb(kfrom, kto) | rto | kto)
-                   & ~(square_bb(kfrom) | rfrom);
+  castlingPath[cr] =   (between_bb(rfrom, rto) | between_bb(kfrom, kto) | rto | kto)
+                    & ~(square_bb(kfrom) | rfrom);
 }
 
 
@@ -859,7 +860,6 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
 
       // Update pawn hash key and prefetch access to pawnsTable
       st->pawnKey ^= Zobrist::psq[pc][from] ^ Zobrist::psq[pc][to];
-      prefetch2(thisThread->pawnsTable[st->pawnKey]);
 
       // Reset rule 50 draw counter
       st->rule50 = 0;

diff --git a/src/position.h b/src/position.h
index 1078e03ed75fa5a4aa42bed002f0d7f820517c09..a3fb16b8e6c2c871a6e9ac3ab5ca3e11d36f9863 100644 (file)
--- a/src/position.h
+++ b/src/position.h
@@ -95,7 +95,7 @@ public:
   template<PieceType Pt> int count() const;
   template<PieceType Pt> const Square* squares(Color c) const;
   template<PieceType Pt> Square square(Color c) const;
-  int semiopen_file(Color c, File f) const;
+  bool is_semiopen_file(Color c, File f) const;
 
   // Castling
   int castling_rights(Color c) const;
@@ -262,7 +262,7 @@ inline Square Position::ep_square() const {
   return st->epSquare;
 }
 
-inline int Position::semiopen_file(Color c, File f) const {
+inline bool Position::is_semiopen_file(Color c, File f) const {
   return !(pieces(c, PAWN) & file_bb(f));
 }
 
@@ -321,7 +321,7 @@ inline bool Position::pawn_passed(Color c, Square s) const {
 
 inline bool Position::advanced_pawn_push(Move m) const {
   return   type_of(moved_piece(m)) == PAWN
-        && relative_rank(sideToMove, from_sq(m)) > RANK_4;
+        && relative_rank(sideToMove, to_sq(m)) > RANK_5;
 }
 
 inline int Position::pawns_on_same_color_squares(Color c, Square s) const {

diff --git a/src/search.cpp b/src/search.cpp
index 44347f79f8b85ec1aee88b579c65c6f9d9b48908..082be4f25587a7ec4d0e329b14890ae3c9446bb2 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -18,6 +18,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <algorithm>
 #include <cassert>
 #include <cmath>
 #include <cstring>   // For std::memset
@@ -894,7 +895,7 @@ moves_loop: // When in check, search starts from here
           &&  move == ttMove
           && !rootNode
           && !excludedMove // Avoid recursive singular search
-      /*  &&  ttValue != VALUE_NONE Already implicit in the next condition */
+       /* &&  ttValue != VALUE_NONE Already implicit in the next condition */
           &&  abs(ttValue) < VALUE_KNOWN_WIN
           && (tte->bound() & BOUND_LOWER)
           &&  tte->depth() >= depth - 3 * ONE_PLY
@@ -1201,8 +1202,8 @@ moves_loop: // When in check, search starts from here
   }
 
 
-  // qsearch() is the quiescence search function, which is called by the main
-  // search function with depth zero, or recursively with depth less than ONE_PLY.
+  // qsearch() is the quiescence search function, which is called by the main search
+  // function with zero depth, or recursively with further decreasing depth per call.
   template <NodeType NT>
   Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) {
 

diff --git a/src/thread.cpp b/src/thread.cpp
index f216c3218ca68ac5b5e3e5effa77c991a42df81b..2f1237a3b0c6b5b02b27636d9c3d78d02f31c84d 100644 (file)
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -20,6 +20,7 @@
 
 #include <cassert>
 
+#include <algorithm> // For std::count
 #include "movegen.h"
 #include "search.h"
 #include "thread.h"

diff --git a/src/timeman.cpp b/src/timeman.cpp
index fafde2aa62033d44a7953d29db8aca23dd78023e..484aaa65998684cf6e6718d5c06d8d3b3a4052fd 100644 (file)
--- a/src/timeman.cpp
+++ b/src/timeman.cpp
@@ -18,6 +18,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <algorithm>
 #include <cfloat>
 #include <cmath>
 

diff --git a/src/ucioption.cpp b/src/ucioption.cpp
index 54f33c9ad9d5656ef7419242937910dc47067dc1..813a0890afe1e4da3a7e9efd49fa3bf79b510079 100644 (file)
--- a/src/ucioption.cpp
+++ b/src/ucioption.cpp
@@ -18,6 +18,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <algorithm>
 #include <cassert>
 #include <ostream>
 #include <sstream>