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[libc] Add bit-rotation functions for unsigned long values 

Generalise the bit rotation implementations to use a common macro, and
add roll() and rorl() to handle unsigned long values.

Each function will still compile down to a single instruction.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
pull/119/head
Michael Brown 2020-07-09 13:51:30 +01:00
parent 98d49e460a
commit f7ddda435c
1 changed files with 26 additions and 8 deletions
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34
src/include/ipxe/rotate.h
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@ -10,44 +10,62 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdint.h>
#define ROLx( data, rotation ) \
( ( (data) << (rotation) ) | \
( (data) >> ( ( 8 * sizeof (data) ) - (rotation) ) ) );
#define RORx( data, rotation ) \
( ( (data) >> (rotation) ) | \
( (data) << ( ( 8 * sizeof (data) ) - (rotation) ) ) );
static inline __attribute__ (( always_inline )) uint8_t
rol8 ( uint8_t data, unsigned int rotation ) {
return ( ( data << rotation ) | ( data >> ( 8 - rotation ) ) );
return ROLx ( data, rotation );
}
static inline __attribute__ (( always_inline )) uint8_t
ror8 ( uint8_t data, unsigned int rotation ) {
return ( ( data >> rotation ) | ( data << ( 8 - rotation ) ) );
return RORx ( data, rotation );
}
static inline __attribute__ (( always_inline )) uint16_t
rol16 ( uint16_t data, unsigned int rotation ) {
return ( ( data << rotation ) | ( data >> ( 16 - rotation ) ) );
return ROLx ( data, rotation );
}
static inline __attribute__ (( always_inline )) uint16_t
ror16 ( uint16_t data, unsigned int rotation ) {
return ( ( data >> rotation ) | ( data << ( 16 - rotation ) ) );
return RORx ( data, rotation );
}
static inline __attribute__ (( always_inline )) uint32_t
rol32 ( uint32_t data, unsigned int rotation ) {
return ( ( data << rotation ) | ( data >> ( 32 - rotation ) ) );
return ROLx ( data, rotation );
}
static inline __attribute__ (( always_inline )) uint32_t
ror32 ( uint32_t data, unsigned int rotation ) {
return ( ( data >> rotation ) | ( data << ( 32 - rotation ) ) );
return RORx ( data, rotation );
}
static inline __attribute__ (( always_inline )) uint64_t
rol64 ( uint64_t data, unsigned int rotation ) {
return ( ( data << rotation ) | ( data >> ( 64 - rotation ) ) );
return ROLx ( data, rotation );
}
static inline __attribute__ (( always_inline )) uint64_t
ror64 ( uint64_t data, unsigned int rotation ) {
return ( ( data >> rotation ) | ( data << ( 64 - rotation ) ) );
return RORx ( data, rotation );
}
static inline __attribute__ (( always_inline )) unsigned long
roll ( unsigned long data, unsigned int rotation ) {
return ROLx ( data, rotation );
}
static inline __attribute__ (( always_inline )) unsigned long
rorl ( unsigned long data, unsigned int rotation ) {
return RORx ( data, rotation );
}
#endif /* _IPXE_ROTATE_H */