2 * Copyright (c) 1990 The Regents of the University of California.
5 * This code is derived from software contributed to Berkeley by
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32 * From: sys/powerpc/powerpc/bcopy.c
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
38 #include <sys/param.h>
39 #include <sys/systm.h>
42 * sizeof(word) MUST BE A POWER OF TWO
43 * SO THAT wmask BELOW IS ALL ONES
45 typedef long word; /* "word" used for optimal copy speed */
47 #define wsize sizeof(word)
48 #define wmask (wsize - 1)
51 * Copy a block of memory, handling overlap.
52 * This is the routine that actually implements
53 * (the portable versions of) bcopy, memcpy, and memmove.
56 memcpy(void *dst0, const void *src0, size_t length)
65 if (length == 0 || dst == src) { /* nothing to do */
70 * Macros: loop-t-times; and loop-t-times, t>0
72 #define TLOOP(s) if (t) TLOOP1(s)
73 #define TLOOP1(s) do { s; } while (--t)
75 if ((unsigned long)dst < (unsigned long)src) {
79 t = (size_t)src; /* only need low bits */
81 if ((t | (uintptr_t)dst) & wmask) {
83 * Try to align operands. This cannot be done
84 * unless the low bits match.
86 if ((t ^ (uintptr_t)dst) & wmask || length < wsize) {
89 t = wsize - (t & wmask);
93 TLOOP1(*dst++ = *src++);
96 * Copy whole words, then mop up any trailing bytes.
99 TLOOP(*(word *)dst = *(const word *)src; src += wsize;
102 TLOOP(*dst++ = *src++);
105 * Copy backwards. Otherwise essentially the same.
106 * Alignment works as before, except that it takes
107 * (t&wmask) bytes to align, not wsize-(t&wmask).
113 if ((t | (uintptr_t)dst) & wmask) {
114 if ((t ^ (uintptr_t)dst) & wmask || length <= wsize) {
121 TLOOP1(*--dst = *--src);
124 TLOOP(src -= wsize; dst -= wsize;
125 *(word *)dst = *(const word *)src);
127 TLOOP(*--dst = *--src);
134 bcopy(const void *src0, void *dst0, size_t length)
137 memcpy(dst0, src0, length);