| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifndef _ALPHA_BYTEORDER_H | 
|  | 2 | #define _ALPHA_BYTEORDER_H | 
|  | 3 |  | 
|  | 4 | #include <asm/types.h> | 
|  | 5 | #include <linux/compiler.h> | 
|  | 6 | #include <asm/compiler.h> | 
|  | 7 |  | 
|  | 8 | #ifdef __GNUC__ | 
|  | 9 |  | 
|  | 10 | static __inline __attribute_const__ __u32 __arch__swab32(__u32 x) | 
|  | 11 | { | 
|  | 12 | /* | 
|  | 13 | * Unfortunately, we can't use the 6 instruction sequence | 
|  | 14 | * on ev6 since the latency of the UNPKBW is 3, which is | 
|  | 15 | * pretty hard to hide.  Just in case a future implementation | 
|  | 16 | * has a lower latency, here's the sequence (also by Mike Burrows) | 
|  | 17 | * | 
|  | 18 | * UNPKBW a0, v0       v0: 00AA00BB00CC00DD | 
|  | 19 | * SLL v0, 24, a0      a0: BB00CC00DD000000 | 
|  | 20 | * BIS v0, a0, a0      a0: BBAACCBBDDCC00DD | 
|  | 21 | * EXTWL a0, 6, v0     v0: 000000000000BBAA | 
|  | 22 | * ZAP a0, 0xf3, a0    a0: 00000000DDCC0000 | 
|  | 23 | * ADDL a0, v0, v0     v0: ssssssssDDCCBBAA | 
|  | 24 | */ | 
|  | 25 |  | 
|  | 26 | __u64 t0, t1, t2, t3; | 
|  | 27 |  | 
|  | 28 | t0 = __kernel_inslh(x, 7);	/* t0 : 0000000000AABBCC */ | 
|  | 29 | t1 = __kernel_inswl(x, 3);	/* t1 : 000000CCDD000000 */ | 
|  | 30 | t1 |= t0;			/* t1 : 000000CCDDAABBCC */ | 
|  | 31 | t2 = t1 >> 16;			/* t2 : 0000000000CCDDAA */ | 
|  | 32 | t0 = t1 & 0xFF00FF00;		/* t0 : 00000000DD00BB00 */ | 
|  | 33 | t3 = t2 & 0x00FF00FF;		/* t3 : 0000000000CC00AA */ | 
|  | 34 | t1 = t0 + t3;			/* t1 : ssssssssDDCCBBAA */ | 
|  | 35 |  | 
|  | 36 | return t1; | 
|  | 37 | } | 
|  | 38 |  | 
|  | 39 | #define __arch__swab32 __arch__swab32 | 
|  | 40 |  | 
|  | 41 | #endif /* __GNUC__ */ | 
|  | 42 |  | 
|  | 43 | #define __BYTEORDER_HAS_U64__ | 
|  | 44 |  | 
|  | 45 | #include <linux/byteorder/little_endian.h> | 
|  | 46 |  | 
|  | 47 | #endif /* _ALPHA_BYTEORDER_H */ |