bitboards.cpp File Reference

#include "stdio.h"
#include "defs.h"
#include "setup.h"

Include dependency graph for bitboards.cpp:

Go to the source code of this file.

Functions
int	popLSB (U64 *bb)
	Pops the least significant 1-bit from a bitboard and returns its index (0–63).
int	countSetBits (U64 b)
	Counts the number of 1-bits in a bitboard.
void	printBitBoard (U64 bb)
	Prints a visual representation of a bitboard to stdout.

Variables
const int	BitTable [64]
	Lookup table for bit index extraction.

Function Documentation

countSetBits()

int countSetBits

(

U64

b

)

Counts the number of 1-bits in a bitboard.

Parameters

b	Bitboard value.

Returns

Number of set bits.

Definition at line 21 of file bitboards.cpp.

popLSB()

int popLSB

(

U64 *

bb

)

Pops the least significant 1-bit from a bitboard and returns its index (0–63).

Parameters

bb	Pointer to the bitboard to modify.

Returns

Index (0–63) of the popped bit.

Definition at line 14 of file bitboards.cpp.

References BitTable.

printBitBoard()

void printBitBoard

(

U64

bb

)

Prints a visual representation of a bitboard to stdout.

'X' marks set bits, '-' marks unset bits.

Parameters

bb	Bitboard to print.

Definition at line 27 of file bitboards.cpp.

References FILE_A, FILE_H, FR2SQ, RANK_1, RANK_8, and SQ64.

Variable Documentation

BitTable

const int BitTable[64]

Initial value:

= {
  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
}

Lookup table for bit index extraction.

Definition at line 7 of file bitboards.cpp.

Referenced by popLSB().