176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman/*
276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * memcpy.c
376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman */
476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman
576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman#include <string.h>
676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman#include <stdint.h>
776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman
876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartmanvoid *memcpy(void *dst, const void *src, size_t n)
976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman{
1076d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman	const char *p = src;
1176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman	char *q = dst;
1276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman#if defined(__i386__)
1376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman	size_t nl = n >> 2;
1476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman	asm volatile ("cld ; rep ; movsl ; movl %3,%0 ; rep ; movsb":"+c" (nl),
1576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman		      "+S"(p), "+D"(q)
1676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman		      :"r"(n & 3));
1776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman#elif defined(__x86_64__)
1876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman	size_t nq = n >> 3;
1976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman	asm volatile ("cld ; rep ; movsq ; movl %3,%%ecx ; rep ; movsb":"+c"
2076d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman		      (nq), "+S"(p), "+D"(q)
2176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman		      :"r"((uint32_t) (n & 7)));
2276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman#else
2376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman	while (n--) {
2476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman		*q++ = *p++;
2576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman	}
2676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman#endif
2776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman
2876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman	return dst;
2976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman}
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