X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.cpp;h=7d86884d12ee51caab40e70e1b14eac56b3f019c;hp=e0ce4d2d771fdeb2453d460fdf06755569a69b48;hb=9a595359628d82026513f7e978d40e944194b057;hpb=dc286d2673ef334c6bab0c4244a49a1b01e63cdc

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index e0ce4d2d..7d86884d 100644
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -348,26 +348,47 @@ union b_union {
 
 Square pop_1st_bit(Bitboard* bb) {
 
-   b_union u;
+   b_union* u;
    Square ret;
 
-   u.b = *bb;
+   u = (b_union*)bb;
 
-   if (u.dw.l)
+   if (u->dw.l)
    {
-       ret = Square(BitTable[((u.dw.l ^ (u.dw.l - 1)) * 0x783a9b23) >> 26]);
-       u.dw.l &= (u.dw.l - 1);
-       *bb = u.b;
+       ret = Square(BitTable[((u->dw.l ^ (u->dw.l - 1)) * 0x783a9b23) >> 26]);
+       u->dw.l &= (u->dw.l - 1);
        return ret;
    }
-   ret = Square(BitTable[((~(u.dw.h ^ (u.dw.h - 1))) * 0x783a9b23) >> 26]);
-   u.dw.h &= (u.dw.h - 1);
-   *bb = u.b;
+   ret = Square(BitTable[((~(u->dw.h ^ (u->dw.h - 1))) * 0x783a9b23) >> 26]);
+   u->dw.h &= (u->dw.h - 1);
    return ret;
 }
 
 #endif
 
+int bitScanReverse32(uint32_t b)
+{
+   int result = 0;
+
+   if (b > 0xFFFF) {
+      b >>= 16;
+      result += 16;
+   }
+   if (b > 0xFF) {
+      b >>= 8;
+      result += 8;
+   }
+   if (b > 0xF) {
+      b >>= 4;
+      result += 4;
+   }
+   if (b > 0x3) {
+      b >>= 2;
+      result += 2;
+   }
+   return result + (b > 0) + (b > 1);
+}
+
 namespace {
 
   // All functions below are used to precompute various bitboards during