1 #ifndef _BITS_BYTESWAP_H
2 #define _BITS_BYTESWAP_H
3 
4 /** @file
5  *
6  * Byte-order swapping functions
7  *
8  */
9 
10 #include <stdint.h>
11 
12 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
13 
14 static inline __attribute__ (( always_inline, const )) uint16_t
__bswap_variable_16(uint16_t x)15 __bswap_variable_16 ( uint16_t x ) {
16 	__asm__ ( "rev16 %0, %1" : "=l" ( x ) : "l" ( x ) );
17 	return x;
18 }
19 
20 static inline __attribute__ (( always_inline )) void
__bswap_16s(uint16_t * x)21 __bswap_16s ( uint16_t *x ) {
22 	*x = __bswap_variable_16 ( *x );
23 }
24 
25 static inline __attribute__ (( always_inline, const )) uint32_t
__bswap_variable_32(uint32_t x)26 __bswap_variable_32 ( uint32_t x ) {
27 	__asm__ ( "rev %0, %1" : "=l" ( x ) : "l" ( x ) );
28 	return x;
29 }
30 
31 static inline __attribute__ (( always_inline )) void
__bswap_32s(uint32_t * x)32 __bswap_32s ( uint32_t *x ) {
33 	*x = __bswap_variable_32 ( *x );
34 }
35 
36 static inline __attribute__ (( always_inline, const )) uint64_t
__bswap_variable_64(uint64_t x)37 __bswap_variable_64 ( uint64_t x ) {
38 	uint32_t in_high = ( x >> 32 );
39 	uint32_t in_low = ( x & 0xffffffffUL );
40 	uint32_t out_high = __bswap_variable_32 ( in_low );
41 	uint32_t out_low = __bswap_variable_32 ( in_high );
42 
43 	return ( ( ( ( uint64_t ) out_high ) << 32 ) |
44 		 ( ( uint64_t ) out_low ) );
45 }
46 
47 static inline __attribute__ (( always_inline )) void
__bswap_64s(uint64_t * x)48 __bswap_64s ( uint64_t *x ) {
49 	*x = __bswap_variable_64 ( *x );
50 }
51 
52 #endif
53