| #ifndef _BITS_STRINGS_H | |
| #define _BITS_STRINGS_H | |
| /** @file | |
| * | |
| * String functions | |
| * | |
| */ | |
| FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); | |
| FILE_SECBOOT ( PERMITTED ); | |
| /** | |
| * Find first (i.e. least significant) set bit | |
| * | |
| * @v value Value | |
| * @ret lsb Least significant bit set in value (LSB=1), or zero | |
| */ | |
| static inline __attribute__ (( always_inline )) int __ffsll ( long long value ){ | |
| unsigned long long bits = value; | |
| unsigned long long lsb; | |
| unsigned int lz; | |
| /* Extract least significant set bit */ | |
| lsb = ( bits & -bits ); | |
| /* Count number of leading zeroes before LSB */ | |
| __asm__ ( "clz %0, %1" : "=r" ( lz ) : "r" ( lsb ) ); | |
| return ( 64 - lz ); | |
| } | |
| /** | |
| * Find first (i.e. least significant) set bit | |
| * | |
| * @v value Value | |
| * @ret lsb Least significant bit set in value (LSB=1), or zero | |
| */ | |
| static inline __attribute__ (( always_inline )) int __ffsl ( long value ) { | |
| return __ffsll ( value ); | |
| } | |
| /** | |
| * Find last (i.e. most significant) set bit | |
| * | |
| * @v value Value | |
| * @ret msb Most significant bit set in value (LSB=1), or zero | |
| */ | |
| static inline __attribute__ (( always_inline )) int __flsll ( long long value ){ | |
| unsigned int lz; | |
| /* Count number of leading zeroes */ | |
| __asm__ ( "clz %0, %1" : "=r" ( lz ) : "r" ( value ) ); | |
| return ( 64 - lz ); | |
| } | |
| /** | |
| * Find last (i.e. most significant) set bit | |
| * | |
| * @v value Value | |
| * @ret msb Most significant bit set in value (LSB=1), or zero | |
| */ | |
| static inline __attribute__ (( always_inline )) int __flsl ( long value ) { | |
| return __flsll ( value ); | |
| } | |
| #endif /* _BITS_STRINGS_H */ |