📄 byteorder.h
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#ifndef _ALPHA_BYTEORDER_H#define _ALPHA_BYTEORDER_H#include <asm/types.h>#ifdef __GNUC__static __inline __u32 __attribute__((__const)) __arch__swab32(__u32 x){ /* * Unfortunately, we can't use the 6 instruction sequence * on ev6 since the latency of the UNPKBW is 3, which is * pretty hard to hide. Just in case a future implementation * has a lower latency, here's the sequence (also by Mike Burrows) * * UNPKBW a0, v0 v0: 00AA00BB00CC00DD * SLL v0, 24, a0 a0: BB00CC00DD000000 * BIS v0, a0, a0 a0: BBAACCBBDDCC00DD * EXTWL a0, 6, v0 v0: 000000000000BBAA * ZAP a0, 0xf3, a0 a0: 00000000DDCC0000 * ADDL a0, v0, v0 v0: ssssssssDDCCBBAA */ __u64 t0, t1, t2, t3; __asm__("inslh %1, 7, %0" /* t0 : 0000000000AABBCC */ : "=r"(t0) : "r"(x)); __asm__("inswl %1, 3, %0" /* t1 : 000000CCDD000000 */ : "=r"(t1) : "r"(x)); t1 |= t0; /* t1 : 000000CCDDAABBCC */ t2 = t1 >> 16; /* t2 : 0000000000CCDDAA */ t0 = t1 & 0xFF00FF00; /* t0 : 00000000DD00BB00 */ t3 = t2 & 0x00FF00FF; /* t3 : 0000000000CC00AA */ t1 = t0 + t3; /* t1 : ssssssssDDCCBBAA */ return t1;}#define __arch__swab32 __arch__swab32#endif /* __GNUC__ */#define __BYTEORDER_HAS_U64__#include <linux/byteorder/little_endian.h>#endif /* _ALPHA_BYTEORDER_H */
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