From f7ddda435cf0d116098351986f89517e3d88af13 Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Thu, 9 Jul 2020 13:51:30 +0100 Subject: [PATCH] [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 --- src/include/ipxe/rotate.h | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) diff --git a/src/include/ipxe/rotate.h b/src/include/ipxe/rotate.h index b5693e3ca..4dea09aeb 100644 --- a/src/include/ipxe/rotate.h +++ b/src/include/ipxe/rotate.h @@ -10,44 +10,62 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #include +#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 */