1#ifndef _ALPHA_SWAB_H 2#define _ALPHA_SWAB_H 3 4#include <linux/types.h> 5#include <linux/compiler.h> 6#include <asm/compiler.h> 7 8#ifdef __GNUC__ 9 10static 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#define __arch_swab32 __arch_swab32 39 40#endif /* __GNUC__ */ 41 42#endif /* _ALPHA_SWAB_H */ 43