2 * Copyright (C) 2004 Joakim Tjernlund
3 * Copyright (C) 2000-2005 Erik Andersen <andersen@uclibc.org>
5 * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
8 /* These are carefully optimized mem*() functions for PPC written in C.
9 * Don't muck around with these function without checking the generated
11 * It is possible to optimize these significantly more by using specific
12 * data cache instructions(mainly dcbz). However that requires knownledge
13 * about the CPU's cache line size.
16 * The cache instructions on MPC8xx CPU's are buggy(they don't update
17 * the DAR register when causing a DTLB Miss/Error) and cannot be
18 * used on 8xx CPU's without a kernel patch to work around this
24 libc_hidden_proto(memcpy)
25 void *memcpy(void *to, const void *from, size_t n)
26 /* PPC can do pre increment and load/store, but not post increment and load/store.
27 Therefore use *++ptr instead of *ptr++. */
29 unsigned long rem, chunks, tmp1, tmp2;
30 unsigned char *tmp_to;
31 unsigned char *tmp_from = (unsigned char *)from;
38 rem = (unsigned long )tmp_to % 4;
43 /* make gcc to load all data, then store it */
44 tmp1 = *(unsigned long *)(tmp_from+4);
46 tmp2 = *(unsigned long *)tmp_from;
47 *(unsigned long *)(tmp_to+4) = tmp1;
49 *(unsigned long *)tmp_to = tmp2;
54 *(unsigned long *)(tmp_to+4) = *(unsigned long *)(tmp_from+4);
63 *++tmp_to = *++tmp_from;
71 *(tmp_to+4) = *(tmp_from+4);
80 libc_hidden_def(memcpy)