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- #ifndef _BITS_STRINGS_H
- #define _BITS_STRINGS_H
-
- /** @file
- *
- * String functions
- *
- */
-
- FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
-
- /**
- * 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 ) {
- unsigned long bits = value;
- unsigned 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 ( 32 - 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 __ffsll ( long long value ){
- unsigned long high = ( value >> 32 );
- unsigned long low = ( value >> 0 );
-
- if ( low ) {
- return ( __ffsl ( low ) );
- } else if ( high ) {
- return ( 32 + __ffsl ( high ) );
- } else {
- return 0;
- }
- }
-
- /**
- * 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 ) {
- unsigned int lz;
-
- /* Count number of leading zeroes */
- __asm__ ( "clz %0, %1" : "=r" ( lz ) : "r" ( value ) );
-
- return ( 32 - 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 __flsll ( long long value ){
- unsigned long high = ( value >> 32 );
- unsigned long low = ( value >> 0 );
-
- if ( high ) {
- return ( 32 + __flsl ( high ) );
- } else if ( low ) {
- return ( __flsl ( low ) );
- } else {
- return 0;
- }
- }
-
- #endif /* _BITS_STRINGS_H */
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