Simplify sliding_attacks()

Easy, almost trivial simplification, I don't understand
how I missed this before !!

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index 67f211a473113a6221c31e27f9f06882634ce8dc..de28e03a05c4ef345ab0d89db30d206046811637 100644 (file)
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -252,7 +252,7 @@ void init_bitboards() {
 
 namespace {
 
 
 namespace {
 

-  Bitboard sliding_attacks(Square sq, Bitboard occupied, Square delta[], Bitboard excluded) {
+  Bitboard sliding_attacks(Square sq, Bitboard occupied, Square delta[]) {

 
     Bitboard attacks = 0;
 
 
     Bitboard attacks = 0;
 


@@ -260,9 +260,7 @@ namespace {
     {
         Square s = sq + delta[i];
 
     {
         Square s = sq + delta[i];
 

-        while (    square_is_ok(s)
-               &&  square_distance(s, s - delta[i]) == 1
-               && !bit_is_set(excluded, s))
+        while (square_is_ok(s) && square_distance(s, s - delta[i]) == 1)

         {
             set_bit(&attacks, s);
 
         {
             set_bit(&attacks, s);
 


@@ -302,22 +300,22 @@ namespace {
     const int  MagicBoosters[][8] = { { 3191, 2184, 1310, 3618, 2091, 1308, 2452, 3996 },
                                       { 1059, 3608,  605, 3234, 3326,   38, 2029, 3043 } };
     RKISS rk;
     const int  MagicBoosters[][8] = { { 3191, 2184, 1310, 3618, 2091, 1308, 2452, 3996 },
                                       { 1059, 3608,  605, 3234, 3326,   38, 2029, 3043 } };
     RKISS rk;

-    Bitboard occupancy[4096], reference[4096], excluded, b;
+    Bitboard occupancy[4096], reference[4096], edges, b;

     int key, maxKey, index, booster, offset = 0;
 
     for (Square s = SQ_A1; s <= SQ_H8; s++)
     {
     int key, maxKey, index, booster, offset = 0;
 
     for (Square s = SQ_A1; s <= SQ_H8; s++)
     {

-        excluded = ((Rank1BB | Rank8BB) & ~rank_bb(s)) | ((FileABB | FileHBB) & ~file_bb(s));
+        edges = ((Rank1BB | Rank8BB) & ~rank_bb(s)) | ((FileABB | FileHBB) & ~file_bb(s));

 
         attack[s] = &attTable[offset];
 
         attack[s] = &attTable[offset];

-        mask[s]   = sliding_attacks(s, EmptyBoardBB, delta, excluded);
+        mask[s]   = sliding_attacks(s, EmptyBoardBB, delta) & ~edges;

         shift[s]  = (CpuIs64Bit ? 64 : 32) - count_1s<CNT32_MAX15>(mask[s]);
 
         // Use Carry-Rippler trick to enumerate all subsets of mask[s]
         b = maxKey = 0;
         do {
             occupancy[maxKey] = b;
         shift[s]  = (CpuIs64Bit ? 64 : 32) - count_1s<CNT32_MAX15>(mask[s]);
 
         // Use Carry-Rippler trick to enumerate all subsets of mask[s]
         b = maxKey = 0;
         do {
             occupancy[maxKey] = b;

-            reference[maxKey++] = sliding_attacks(s, b, delta, EmptyBoardBB);
+            reference[maxKey++] = sliding_attacks(s, b, delta);

             b = (b - mask[s]) & mask[s];
         } while (b);
 
             b = (b - mask[s]) & mask[s];
         } while (b);
 

diff --git a/src/search.cpp b/src/search.cpp
index 2e12f82e2a44ff16b3c31a6fc75afb97e715db5d..6a16368f288f11e00892f0aea0a34282cc0fe5cd 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1649,7 +1649,6 @@ split_point_start: // At split points actual search starts from here
 
     assert(move_is_ok(m));
     assert(threat && move_is_ok(threat));
 
     assert(move_is_ok(m));
     assert(threat && move_is_ok(threat));

-    assert(!pos.move_gives_check(m));

     assert(!pos.move_is_capture(m) && !move_is_promotion(m));
     assert(!pos.move_is_passed_pawn_push(m));
 
     assert(!pos.move_is_capture(m) && !move_is_promotion(m));
     assert(!pos.move_is_passed_pawn_push(m));