xref: /reactos/sdk/lib/fslib/vfatlib/check/byteorder.h (revision 5100859e)
1 #ifndef _I386_BYTEORDER_H
2 #define _I386_BYTEORDER_H
3 
4 //#include "types.h"
5 #include "compiler.h"
6 
7 #ifdef __GNUC__
8 
9 /* For avoiding bswap on i386 */
10 //#ifdef __KERNEL__
11 //#include <linux/config.h>
12 //#endif
13 
14 static __inline__ __attribute_const__ __u32 ___arch__swab32(__u32 x)
15 {
16 #ifdef CONFIG_X86_BSWAP
17 	__asm__("bswap %0" : "=r" (x) : "0" (x));
18 #else
19 	__asm__("xchgb %b0,%h0\n\t"	/* swap lower bytes	*/
20 		"rorl $16,%0\n\t"	/* swap words		*/
21 		"xchgb %b0,%h0"		/* swap higher bytes	*/
22 		:"=q" (x)
23 		: "0" (x));
24 #endif
25 	return x;
26 }
27 
28 static __inline__ __attribute_const__ __u64 ___arch__swab64(__u64 val)
29 {
30 	union {
31 		struct { __u32 a,b; } 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" : "=r" (v.s.a), "=r" (v.s.b) : "0" (v.s.a), "1" (v.s.b));
43 #endif
44 	return v.u;
45 }
46 
47 /* Do not define swab16.  Gcc is smart enough to recognize "C" version and
48    convert it into rotation or exhange.  */
49 
50 #define __arch__swab64(x) ___arch__swab64(x)
51 #define __arch__swab32(x) ___arch__swab32(x)
52 
53 #define __BYTEORDER_HAS_U64__
54 
55 #endif /* __GNUC__ */
56 
57 //#include "little_endian.h"
58 
59 #endif /* _I386_BYTEORDER_H */
60