stellar

Use builtin bit instructions when available

3 files changed, 28 insertions(+), 49 deletions(-)

diff --git a/ CMakeLists.txt b/ CMakeLists.txt

@@ -3,7 +3,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON) project( Stellar

VERSION 0.0.5

VERSION 0.0.6

DESCRIPTION "Chess engine written in C" HOMEPAGE_URL https://git.dimitrijedobrota.com/stellar.git LANGUAGES C

diff --git a/ src/include/utils.h b/ src/include/utils.h

@@ -1,6 +1,8 @@ #ifndef STELLAR_UTILS_H #define STELLAR_UTILS_H

#include <inttypes.h>

// useful macros #define MAX(a, b) ((a > b) ? a : b) #define MIN(a, b) ((a < b) ? a : b)

@@ -21,14 +23,12 @@ extern const U64 notHFile; #define bit_get(bitboard, square) (((bitboard) >> (square)) & C64(1)) #define bit_set(bitboard, square) ((bitboard) |= C64(1) << (square)) #define bit_pop(bitboard, square) ((bitboard) &= ~(C64(1) << (square)))

int bit_count(U64 bitboard);

int bit_lsb_index(U64 bitboard);

uint8_t bit_count(U64 bitboard);

uint8_t bit_lsb_index(U64 bitboard);

#define bitboard_for_each_bit(var, bb) \ for (var = bit_lsb_index(bb); bb; bit_pop(bb, var), var = bit_lsb_index(bb))

void bitboard_print(U64 bitboard);

// squares // clang-format off enum enumSquare {

diff --git a/ src/utils/utils.c b/ src/utils/utils.c

@@ -1,15 +1,31 @@ #include <stdio.h>

#ifdef WIN64

#include <widnows.h>

#else

#include <sys/time.h>

#endif

#include "utils.h"

const U64 universe = C64(0xffffffffffffffff); //

const U64 notAFile = C64(0xfefefefefefefefe); // ~0x0101010101010101

const U64 notHFile = C64(0x7f7f7f7f7f7f7f7f); // ~0x8080808080808080

const U64 universe = C64(0xffffffffffffffff);

const U64 notAFile = C64(0xfefefefefefefefe);

const U64 notHFile = C64(0x7f7f7f7f7f7f7f7f);

inline uint8_t bit_count(U64 bitboard) {

#if __has_builtin(__builtin_popcountll)

return __builtin_popcountll(bitboard);

#endif

int count = 0;

for (; bitboard > 0; bitboard &= bitboard - 1)

count++;

return count;

}

inline uint8_t bit_lsb_index(U64 bitboard) {

#if __has_builtin(__builtin_ffsll)

return __builtin_ffsll(bitboard) - 1;

#endif

if (!bitboard) return -1;

return bit_count((bitboard & -bitboard) - 1);

}

U64 soutOne(U64 b) { return b >> 8; } U64 nortOne(U64 b) { return b << 8; }

@@ -41,45 +57,8 @@ Square coordinates_to_square(const char *cord) { return (cord[1] - '1') * 8 + (cord[0] - 'a'); }

int bit_count(U64 bitboard) {

int count = 0;

while (bitboard > 0) {

count++;

bitboard &= bitboard - 1;

}

return count;

}

int bit_lsb_index(U64 bitboard) {

if (!bitboard) return -1;

return bit_count((bitboard & -bitboard) - 1);

}

void bitboard_print(U64 bitboard) {

for (int rank = 0; rank < 8; rank++) {

for (int file = 0; file < 8; file++) {

Square square = (7 - rank) * 8 + file;

if (!file) printf(" %d ", 8 - rank);

printf("%d ", bit_get(bitboard, square) ? 1 : 0);

}

printf("\n");

}

printf("\n A B C D E F G H\n\n");

printf(" Bitboard: %llud\n\n", bitboard);

}

int get_time_ms(void) {

#ifdef WIN64

return GetTickCount();

#else

struct timeval time; gettimeofday(&time, NULL); return time.tv_sec * 1000 + time.tv_usec / 1000;

#endif

}