bitops.h
上传用户:rrhhcc
上传日期:2015-12-11
资源大小:54129k
文件大小:1k
- #ifndef BITOPS_H
- #define BITOPS_H
- #include "string.h" /* due to memset */
- /* determines if bit number "bit_nb" is set in array "arr" */
- #define IS_BIT_SET(arr, bit_nb) (((unsigned char*) arr)[(bit_nb) >> 3] &
- (((unsigned char) 1) << ((bit_nb) & 7)))
- /* determines if bit number "bit_nb" is set in array "arr" */
- #define IS_BIT_CLEARED(arr, bit_nb) (! IS_BIT_SET(arr, bit_nb))
- /* resets bit "bit_nb" in array "arr" */
- #define RESET_BIT(arr, bit_nb) (((unsigned char*) arr)[(bit_nb) >> 3] &= ~(((unsigned char) 1) << ((bit_nb) & 7)))
- /* sets bit "bit_nb" in array "arr" */
- #define SET_BIT(arr, bit_nb) (((unsigned char*) arr)[(bit_nb) >> 3] |= ((unsigned char) 1) << ((bit_nb) & 7))
- /* set the first nb_bits in array arr */
- inline void SET_ALL_BITS(unsigned char* arr, unsigned long nb_bits)
- {
- memset(arr, 255, nb_bits >> 3);
- if(nb_bits & 7) {
- arr[nb_bits >> 3] |= ((unsigned char) 255) >> (8 - (nb_bits & 7));
- }
- }
- /* reset the first nb_bits in array arr */
- inline void RESET_ALL_BITS(unsigned char* arr, unsigned long nb_bits)
- {
- memset(arr, 0, nb_bits >> 3);
- if(nb_bits & 7) {
- arr[nb_bits >> 3] &= ((unsigned char) 255) << (nb_bits & 7);
- }
- }
- #endif