diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index b36f8a29..794f54cf 100644
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -17,16 +17,14 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <algorithm>
 #include <cstring>
 #include <iostream>
-#include <algorithm>
 
 #include "bitboard.h"
 #include "bitcount.h"
 #include "rkiss.h"
 
-// Global bitboards definitions with static storage duration are
-// automatically set to zero before enter main().
 Bitboard RMasks[64];
 Bitboard RMagics[64];
 Bitboard* RAttacks[64];
@@ -151,18 +149,14 @@ Square pop_1st_bit(Bitboard* bb) {
 #endif // !defined(USE_BSFQ)
 
 
-/// init_bitboards() initializes various bitboard arrays. It is called during
+/// bitboards_init() initializes various bitboard arrays. It is called during
 /// program initialization.
 
-void init_bitboards() {
+void bitboards_init() {
 
   for (Bitboard b = 0; b < 256; b++)
       BitCount8Bit[b] = (uint8_t)count_1s<CNT32_MAX15>(b);
 
-  for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
-      for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
-          SquareDistance[s1][s2] = std::max(file_distance(s1, s2), rank_distance(s1, s2));
-
   SquaresByColorBB[DARK]  =  0xAA55AA55AA55AA55ULL;
   SquaresByColorBB[LIGHT] = ~SquaresByColorBB[DARK];
 
@@ -199,10 +193,14 @@ void init_bitboards() {
       for (Square s = SQ_A1; s <= SQ_H8; s++)
       {
           SquaresInFrontMask[c][s] = in_front_bb(c, s) & file_bb(s);
-          PassedPawnMask[c][s]     = in_front_bb(c, s) & this_and_neighboring_files_bb(s);
-          AttackSpanMask[c][s]     = in_front_bb(c, s) & neighboring_files_bb(s);
+          PassedPawnMask[c][s]     = in_front_bb(c, s) & this_and_neighboring_files_bb(file_of(s));
+          AttackSpanMask[c][s]     = in_front_bb(c, s) & neighboring_files_bb(file_of(s));
       }
 
+  for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
+      for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
+          SquareDistance[s1][s2] = std::max(file_distance(s1, s2), rank_distance(s1, s2));
+
   for (int i = 0; i < 64; i++)
       if (!CpuIs64Bit) // Matt Taylor's folding trick for 32 bit systems
       {
@@ -276,6 +274,7 @@ namespace {
     return attacks;
   }
 
+
   Bitboard pick_random(Bitboard mask, RKISS& rk, int booster) {
 
     Bitboard magic;
diff --git a/src/bitboard.h b/src/bitboard.h
index 09c00597..1c8a8c22 100644
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -125,29 +125,21 @@ inline Bitboard file_bb(Square s) {
 }
 
 
-/// neighboring_files_bb takes a file or a square as input and returns a
-/// bitboard representing all squares on the neighboring files.
+/// neighboring_files_bb takes a file as input and returns a bitboard representing
+/// all squares on the neighboring files.
 
 inline Bitboard neighboring_files_bb(File f) {
   return NeighboringFilesBB[f];
 }
 
-inline Bitboard neighboring_files_bb(Square s) {
-  return NeighboringFilesBB[file_of(s)];
-}
 
-
-/// this_and_neighboring_files_bb takes a file or a square as input and returns
-/// a bitboard representing all squares on the given and neighboring files.
+/// this_and_neighboring_files_bb takes a file as input and returns a bitboard
+/// representing all squares on the given and neighboring files.
 
 inline Bitboard this_and_neighboring_files_bb(File f) {
   return ThisAndNeighboringFilesBB[f];
 }
 
-inline Bitboard this_and_neighboring_files_bb(Square s) {
-  return ThisAndNeighboringFilesBB[file_of(s)];
-}
-
 
 /// in_front_bb() takes a color and a rank or square as input, and returns a
 /// bitboard representing all the squares on all ranks in front of the rank
@@ -291,6 +283,6 @@ extern Square pop_1st_bit(Bitboard* b);
 
 
 extern void print_bitboard(Bitboard b);
-extern void init_bitboards();
+extern void bitboards_init();
 
 #endif // !defined(BITBOARD_H_INCLUDED)
diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 7e4f963e..6b15f6c7 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -850,7 +850,7 @@ namespace {
 
         // Increase the bonus if the passed pawn is supported by a friendly pawn
         // on the same rank and a bit smaller if it's on the previous rank.
-        supportingPawns = pos.pieces(PAWN, Us) & neighboring_files_bb(s);
+        supportingPawns = pos.pieces(PAWN, Us) & neighboring_files_bb(file_of(s));
         if (supportingPawns & rank_bb(s))
             ebonus += Value(r * 20);
 
@@ -979,7 +979,7 @@ namespace {
         pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
 
         // Generate list of blocking pawns and supporters
-        supporters = neighboring_files_bb(s) & candidates;
+        supporters = neighboring_files_bb(file_of(s)) & candidates;
         opposed = squares_in_front_of(loserSide, s) & pos.pieces(PAWN, winnerSide);
         blockers = passed_pawn_mask(loserSide, s) & pos.pieces(PAWN, winnerSide);
 
diff --git a/src/main.cpp b/src/main.cpp
index a437f883..1a830970 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -35,7 +35,7 @@ extern void kpk_bitbase_init();
 
 int main(int argc, char* argv[]) {
 
-  init_bitboards();
+  bitboards_init();
   Position::init();
   kpk_bitbase_init();
   Search::init();
diff --git a/src/pawns.cpp b/src/pawns.cpp
index 52bc9f88..d5514e2e 100644
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -223,7 +223,7 @@ Score PawnInfo::updateShelter(const Position& pos, Square ksq) {
 
   if (relative_rank(Us, ksq) <= RANK_4)
   {
-      pawns = pos.pieces(PAWN, Us) & this_and_neighboring_files_bb(ksq);
+      pawns = pos.pieces(PAWN, Us) & this_and_neighboring_files_bb(file_of(ksq));
       r = ksq & (7 << 3);
       for (int i = 0; i < 3; i++)
       {