arch/x86/boot/compressed/string.c

#include "../string.c"

#ifdef CONFIG_X86_32
void *__memcpy(void *dest, const void *src, size_t n)
{
	int d0, d1, d2;
	asm volatile(
		"rep ; movsl\n\t"
		"movl %4,%%ecx\n\t"
		"rep ; movsb\n\t"
		: "=&c" (d0), "=&D" (d1), "=&S" (d2)
		: "0" (n >> 2), "g" (n & 3), "1" (dest), "2" (src)
		: "memory");

	return dest;
}
#else
void *__memcpy(void *dest, const void *src, size_t n)
{
	long d0, d1, d2;
	asm volatile(
		"rep ; movsq\n\t"
		"movq %4,%%rcx\n\t"
		"rep ; movsb\n\t"
		: "=&c" (d0), "=&D" (d1), "=&S" (d2)
		: "0" (n >> 3), "g" (n & 7), "1" (dest), "2" (src)
		: "memory");

	return dest;
}
#endif

void *memset(void *s, int c, size_t n)
{
	int i;
	char *ss = s;

	for (i = 0; i < n; i++)
		ss[i] = c;
	return s;
}

/*
 * This memcpy is overlap safe (i.e. it is memmove without conflicting
 * with other definitions of memmove from the various decompressors.
 */
void *memcpy(void *dest, const void *src, size_t n)
{
	unsigned char *d = dest;
	const unsigned char *s = src;

	if (d <= s || d - s >= n)
		return __memcpy(dest, src, n);

	while (n-- > 0)
		d[n] = s[n];

	return dest;
}