From 48b0d41220c35ce50f5fc26c77b2879a75d104d2 Mon Sep 17 00:00:00 2001
From: Marco Costalba <mcostalba@gmail.com>
Date: Fri, 3 Jul 2009 12:28:11 +0200
Subject: [PATCH] Microptimize pawns info access

Avoid indirect calling of piece_of_color_and_type(c, PAWN) and its
alias pawns(c) in the pawn evaluation loop, but use the pawns
bitboards accessed only once before entering the loop.

Also explicitly mark functions as static to better self-document.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
---
 src/pawns.cpp  | 14 +++++++-------
 src/position.h | 29 +++++++++++++++++------------
 2 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/src/pawns.cpp b/src/pawns.cpp
index 8d29185e..d0523ab6 100644
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -193,7 +193,7 @@ PawnInfo *PawnInfoTable::get_pawn_info(const Position &pos) {
 
     // Initialize pawn storm scores by giving bonuses for open files
     for (File f = FILE_A; f <= FILE_H; f++)
-        if (pos.file_is_half_open(us, f))
+        if (Position::file_is_half_open(ourPawns, f))
         {
             pi->ksStormValue[us] += KStormOpenFileBonus[f];
             pi->qsStormValue[us] += QStormOpenFileBonus[f];
@@ -213,9 +213,9 @@ PawnInfo *PawnInfoTable::get_pawn_info(const Position &pos) {
         pi->halfOpenFiles[us] &= ~(1 << f);
 
         // Passed, isolated or doubled pawn?
-        passed = pos.pawn_is_passed(us, s);
-        isolated = pos.pawn_is_isolated(us, s);
-        doubled = pos.pawn_is_doubled(us, s);
+        passed = Position::pawn_is_passed(theirPawns, us, s);
+        isolated = Position::pawn_is_isolated(ourPawns, s);
+        doubled = Position::pawn_is_doubled(ourPawns, us, s);
 
         // We calculate kingside and queenside pawn storm
         // scores for both colors. These are used when evaluating
@@ -319,7 +319,7 @@ PawnInfo *PawnInfoTable::get_pawn_info(const Position &pos) {
 
         // Test for candidate passed pawn
         candidate =    !passed
-                     && pos.file_is_half_open(them, f)
+                     && Position::file_is_half_open(theirPawns, f)
                      && (  count_1s_max_15(neighboring_files_bb(f) & (behind_bb(us, r) | rank_bb(r)) & ourPawns)
                          - count_1s_max_15(neighboring_files_bb(f) & in_front_bb(us, r)              & theirPawns)
                          >= 0);
@@ -339,7 +339,7 @@ PawnInfo *PawnInfoTable::get_pawn_info(const Position &pos) {
         {
             mv -= IsolatedPawnMidgamePenalty[f];
             ev -= IsolatedPawnEndgamePenalty[f];
-            if (pos.file_is_half_open(them, f))
+            if (Position::file_is_half_open(theirPawns, f))
             {
                 mv -= IsolatedPawnMidgamePenalty[f] / 2;
                 ev -= IsolatedPawnEndgamePenalty[f] / 2;
@@ -354,7 +354,7 @@ PawnInfo *PawnInfoTable::get_pawn_info(const Position &pos) {
         {
             mv -= BackwardPawnMidgamePenalty[f];
             ev -= BackwardPawnEndgamePenalty[f];
-            if (pos.file_is_half_open(them, f))
+            if (Position::file_is_half_open(theirPawns, f))
             {
                 mv -= BackwardPawnMidgamePenalty[f] / 2;
                 ev -= BackwardPawnEndgamePenalty[f] / 2;
diff --git a/src/position.h b/src/position.h
index 9730d3dc..2762d2f8 100644
--- a/src/position.h
+++ b/src/position.h
@@ -244,12 +244,13 @@ public:
 
   // Information about pawns
   bool pawn_is_passed(Color c, Square s) const;
-  bool pawn_is_isolated(Color c, Square s) const;
-  bool pawn_is_doubled(Color c, Square s) const;
+  static bool pawn_is_passed(Bitboard theirPawns, Color c, Square s);
+  static bool pawn_is_isolated(Bitboard ourPawns, Square s);
+  static bool pawn_is_doubled(Bitboard ourPawns, Color c, Square s);
 
   // Open and half-open files
-  bool file_is_open(File f) const;
-  bool file_is_half_open(Color c, File f) const;
+  static bool file_is_open(Bitboard pawns, File f);
+  static bool file_is_half_open(Bitboard pawns, File f);
 
   // Weak squares
   bool square_is_weak(Square s, Color c) const;
@@ -591,20 +592,24 @@ inline bool Position::pawn_is_passed(Color c, Square s) const {
   return !(pawns(opposite_color(c)) & passed_pawn_mask(c, s));
 }
 
-inline bool Position::pawn_is_isolated(Color c, Square s) const {
-  return !(pawns(c) & neighboring_files_bb(s));
+inline bool Position::pawn_is_passed(Bitboard theirPawns, Color c, Square s) {
+  return !(theirPawns & passed_pawn_mask(c, s));
 }
 
-inline bool Position::pawn_is_doubled(Color c, Square s) const {
-  return pawns(c) & squares_behind(c, s);
+inline bool Position::pawn_is_isolated(Bitboard ourPawns, Square s) {
+  return !(ourPawns & neighboring_files_bb(s));
 }
 
-inline bool Position::file_is_open(File f) const {
-  return !(pawns() & file_bb(f));
+inline bool Position::pawn_is_doubled(Bitboard ourPawns, Color c, Square s) {
+  return ourPawns & squares_behind(c, s);
 }
 
-inline bool Position::file_is_half_open(Color c, File f) const {
-  return !(pawns(c) & file_bb(f));
+inline bool Position::file_is_open(Bitboard pawns, File f) {
+  return !(pawns & file_bb(f));
+}
+
+inline bool Position::file_is_half_open(Bitboard pawns, File f) {
+  return !(pawns & file_bb(f));
 }
 
 inline bool Position::square_is_weak(Square s, Color c) const {
-- 
2.39.2