1 #ifndef _BITS_BYTESWAP_H
2 #define _BITS_BYTESWAP_H
6 * Byte-order swapping functions
12 FILE_LICENCE ( GPL2_OR_LATER );
14 static inline __attribute__ (( always_inline, const )) uint16_t
15 __bswap_variable_16 ( uint16_t x ) {
16 __asm__ ( "xchgb %b0,%h0" : "=q" ( x ) : "0" ( x ) );
20 static inline __attribute__ (( always_inline )) void
21 __bswap_16s ( uint16_t *x ) {
22 __asm__ ( "rorw $8, %0" : "+m" ( *x ) );
25 static inline __attribute__ (( always_inline, const )) uint32_t
26 __bswap_variable_32 ( uint32_t x ) {
27 __asm__ ( "bswapl %0" : "=r" ( x ) : "0" ( x ) );
31 static inline __attribute__ (( always_inline )) void
32 __bswap_32s ( uint32_t *x ) {
33 __asm__ ( "bswapl %0" : "=r" ( *x ) : "0" ( *x ) );
36 static inline __attribute__ (( always_inline, const )) uint64_t
37 __bswap_variable_64 ( uint64_t x ) {
38 uint32_t in_high = ( x >> 32 );
39 uint32_t in_low = ( x & 0xffffffffUL );
43 __asm__ ( "bswapl %0\n\t"
46 : "=r" ( out_high ), "=r" ( out_low )
47 : "0" ( in_high ), "1" ( in_low ) );
49 return ( ( ( ( uint64_t ) out_high ) << 32 ) |
50 ( ( uint64_t ) out_low ) );
53 static inline __attribute__ (( always_inline )) void
54 __bswap_64s ( uint64_t *x ) {
56 uint32_t __attribute__ (( may_alias )) low;
57 uint32_t __attribute__ (( may_alias )) high;
58 } __attribute__ (( may_alias )) *dwords = ( ( void * ) x );
61 __asm__ ( "movl %0,%2\n\t"
66 : "+m" ( dwords->low ), "+m" ( dwords->high ),
70 #endif /* _BITS_BYTESWAP_H */