1// Copyright 2016 The Fuchsia Authors 2// Copyright (c) 2008 Travis Geiselbrecht 3// 4// Use of this source code is governed by a MIT-style 5// license that can be found in the LICENSE file or at 6// https://opensource.org/licenses/MIT 7 8#include <string.h> 9#include <sys/types.h> 10 11 12#if !_ASM_MEMCPY 13 14typedef long word; 15 16#define lsize sizeof(word) 17#define lmask (lsize - 1) 18 19void *memcpy(void *dest, const void *src, size_t count) 20{ 21 char *d = (char *)dest; 22 const char *s = (const char *)src; 23 int len; 24 25 if (count == 0 || dest == src) 26 return dest; 27 28 if (((long)d | (long)s) & lmask) { 29 // src and/or dest do not align on word boundary 30 if ((((long)d ^ (long)s) & lmask) || (count < lsize)) 31 len = count; // copy the rest of the buffer with the byte mover 32 else 33 len = lsize - ((long)d & lmask); // move the ptrs up to a word boundary 34 35 count -= len; 36 for (; len > 0; len--) 37 *d++ = *s++; 38 } 39 for (len = count / lsize; len > 0; len--) { 40 *(word *)d = *(word *)s; 41 d += lsize; 42 s += lsize; 43 } 44 for (len = count & lmask; len > 0; len--) 45 *d++ = *s++; 46 47 return dest; 48} 49 50#endif 51