bitboards.cpp

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// bitboards.c
 
#include "stdio.h"
#include "defs.h"
#include "setup.h"
 
const int BitTable[64] = {
  63, 30, 3, 32, 25, 41, 22, 33, 15, 50, 42, 13, 11, 53, 19, 34, 61, 29, 2,
  51, 21, 43, 45, 10, 18, 47, 1, 54, 9, 57, 0, 35, 62, 31, 40, 4, 49, 5, 52,
  26, 60, 6, 23, 44, 46, 27, 56, 16, 7, 39, 48, 24, 59, 14, 12, 55, 38, 28,
  58, 20, 37, 17, 36, 8
};
 
int popLSB(U64 *bb) {
  U64 b = *bb ^ (*bb - 1);
  unsigned int fold = (unsigned) ((b & 0xffffffff) ^ (b >> 32));
  *bb &= (*bb - 1);
  return BitTable[(fold * 0x783a9b23) >> 26];
}
 
int countSetBits(U64 b) {
  int r;
  for(r = 0; b; r++, b &= b - 1);
  return r;
}
 
void printBitBoard(U64 bb) {
 
    U64 shiftMe = 1ULL;
    
    int rank = 0;
    int file = 0;
    int sq = 0;
    int sq64 = 0;
    
    printf("\n");
    for(rank = RANK_8; rank >= RANK_1; --rank) {
        for(file = FILE_A; file <= FILE_H; ++file) {
            sq = FR2SQ(file,rank); // 120 based        
            sq64 = SQ64(sq); // 64 based
            
            if((shiftMe << sq64) & bb) 
                printf("X");
            else 
                printf("-");
                
        }
        printf("\n");
    }  
    printf("\n\n");
}