1 #ifndef _I386_BYTEORDER_H
2 #define _I386_BYTEORDER_H
3 
4 #include <asm/types.h>
5 #include <linux/compiler.h>
6 
7 #ifdef __GNUC__
8 
9 /* For avoiding bswap on i386 */
10 #ifdef __KERNEL__
11 #include <linux/config.h>
12 #endif
13 
___arch__swab32(__u32 x)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 /* gcc should generate this for open coded C now too. May be worth switching to
29    it because inline assembly cannot be scheduled. -AK */
___arch__swab16(__u16 x)30 static __inline__ __attribute_const__ __u16 ___arch__swab16(__u16 x)
31 {
32 	__asm__("xchgb %b0,%h0"		/* swap bytes		*/
33 		: "=q" (x)
34 		:  "0" (x));
35 		return x;
36 }
37 
38 
___arch__swab64(__u64 val)39 static inline __u64 ___arch__swab64(__u64 val)
40 {
41 	union {
42 		struct { __u32 a,b; } s;
43 		__u64 u;
44 	} v;
45 	v.u = val;
46 #ifdef CONFIG_X86_BSWAP
47 	asm("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
48 	    : "=r" (v.s.a), "=r" (v.s.b)
49 	    : "0" (v.s.a), "1" (v.s.b));
50 #else
51    v.s.a = ___arch__swab32(v.s.a);
52 	v.s.b = ___arch__swab32(v.s.b);
53 	asm("xchgl %0,%1" : "=r" (v.s.a), "=r" (v.s.b) : "0" (v.s.a), "1" (v.s.b));
54 #endif
55 	return v.u;
56 }
57 
58 #define __arch__swab64(x) ___arch__swab64(x)
59 #define __arch__swab32(x) ___arch__swab32(x)
60 #define __arch__swab16(x) ___arch__swab16(x)
61 
62 #define __BYTEORDER_HAS_U64__
63 
64 #endif /* __GNUC__ */
65 
66 #include <linux/byteorder/little_endian.h>
67 
68 #endif /* _I386_BYTEORDER_H */
69