3 

     4 #include <asm/types.h>

     5 #include <linux/compiler.h>

     6 

     7 #ifdef __GNUC__

     8 

     9 #ifdef __i386__

    10 

    11 static inline __attribute_const__ __u32 ___arch__swab32(__u32 x)

    12 {

    13 #ifdef CONFIG_X86_BSWAP

    14 	asm("bswap %0" : "=r" (x) : "0" (x));

    15 #else

    16 	asm("xchgb %b0,%h0\n\t"	/* swap lower bytes	*/

    17 	    "rorl $16,%0\n\t"	/* swap words		*/

    18 	    "xchgb %b0,%h0"	/* swap higher bytes	*/

    19 	    : "=q" (x)

    20 	    : "0" (x));

    21 #endif

    22 	return x;

    23 }

    24 

    25 static inline __attribute_const__ __u64 ___arch__swab64(__u64 val)

    26 {

    27 	union {

    28 		struct {

    29 			__u32 a;

    30 			__u32 b;

    31 		} s;

    32 		__u64 u;

    33 	} v;

    34 	v.u = val;

    35 #ifdef CONFIG_X86_BSWAP

    36 	asm("bswapl %0 ; bswapl %1 ; xchgl %0,%1"

    37 	    : "=r" (v.s.a), "=r" (v.s.b)

    38 	    : "0" (v.s.a), "1" (v.s.b));

    39 #else

    40 	v.s.a = ___arch__swab32(v.s.a);

    41 	v.s.b = ___arch__swab32(v.s.b);

    42 	asm("xchgl %0,%1"

    43 	    : "=r" (v.s.a), "=r" (v.s.b)

    44 	    : "0" (v.s.a), "1" (v.s.b));

    45 #endif

    46 	return v.u;

    47 }

    48 

    49 #else /* __i386__ */

    50 

    51 static inline __attribute_const__ __u64 ___arch__swab64(__u64 x)

    52 {

    53 	asm("bswapq %0"

    54 	    : "=r" (x)

    55 	    : "0" (x));

    56 	return x;

    57 }

    58 

    59 static inline __attribute_const__ __u32 ___arch__swab32(__u32 x)

    60 {

    61 	asm("bswapl %0"

    62 	    : "=r" (x)

    63 	    : "0" (x));

    64 	return x;

    65 }

    66 

    67 #endif

    68 

    69 /* Do not define swab16.  Gcc is smart enough to recognize "C" version and

    70    convert it into rotation or exhange.  */

    71 

    72 #define __arch__swab64(x) ___arch__swab64(x)

    73 #define __arch__swab32(x) ___arch__swab32(x)

    74 

    75 #define __BYTEORDER_HAS_U64__

    76 

    77 #endif /* __GNUC__ */