37 lines
535 B
C
37 lines
535 B
C
/*
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* memmove.c
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*/
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#include <string.h>
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void *memmove(void *dst, const void *src, size_t n)
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{
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const char *p = src;
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char *q = dst;
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#if defined(__i386__) || defined(__x86_64__)
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if (q < p) {
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asm volatile("cld; rep; movsb"
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: "+c" (n), "+S"(p), "+D"(q));
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} else {
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p += (n - 1);
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q += (n - 1);
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asm volatile("std; rep; movsb; cld"
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: "+c" (n), "+S"(p), "+D"(q));
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}
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#else
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if (q < p) {
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while (n--) {
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*q++ = *p++;
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}
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} else {
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p += n;
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q += n;
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while (n--) {
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*--q = *--p;
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}
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}
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#endif
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return dst;
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}
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