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authorMarkus Uhlin <markus@nifty-networks.net>2023-12-07 21:31:49 +0100
committerMarkus Uhlin <markus@nifty-networks.net>2023-12-07 21:31:49 +0100
commit79b59f9b30fb6a1fdf8c3efb446271f7cb00d434 (patch)
treef6ade4ccbc3af20d825edacfd12b5da8ded8d240 /FICS/memmove.c
FICS 1.6.2
Diffstat (limited to 'FICS/memmove.c')
-rw-r--r--FICS/memmove.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/FICS/memmove.c b/FICS/memmove.c
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+/*-
+ * Copyright (c) 1990, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bcopy.c 8.1 (Berkeley) 6/4/93";
+#endif /* LIBC_SCCS and not lint */
+
+/* #include <sys/cdefs.h>
+*/
+#include <string.h>
+
+/*
+ * sizeof(word) MUST BE A POWER OF TWO
+ * SO THAT wmask BELOW IS ALL ONES
+ */
+typedef int word; /* "word" used for optimal copy speed */
+
+#define wsize sizeof(word)
+#define wmask (wsize - 1)
+
+/*
+ * Copy a block of memory, handling overlap.
+ * This is the routine that actually implements
+ * (the portable versions of) bcopy, memcpy, and memmove.
+ */
+void *
+ memmove(dst0, src0, length)
+void *dst0;
+const void *src0;
+register size_t length;
+{
+ register char *dst = dst0;
+ register const char *src = src0;
+ register size_t t;
+
+ if (length == 0 || dst == src)/* nothing to do */
+ goto done;
+
+ /* Macros: loop-t-times; and loop-t-times, t>0 */
+#define TLOOP(s) if (t) TLOOP1(s)
+#define TLOOP1(s) do { s; } while (--t)
+
+ if ((unsigned long) dst < (unsigned long) src) {
+ /* Copy forward. */
+ t = (int) src; /* only need low bits */
+ if ((t | (int) dst) & wmask) {
+ /* Try to align operands. This cannot be done unless the low bits
+ match. */
+ if ((t ^ (int) dst) & wmask || length < wsize)
+ t = length;
+ else
+ t = wsize - (t & wmask);
+ length -= t;
+ TLOOP1(*dst++ = *src++);
+ }
+ /* Copy whole words, then mop up any trailing bytes. */
+ t = length / wsize;
+ TLOOP(*(word *) dst = *(word *) src;
+ src += wsize;
+ dst += wsize);
+ t = length & wmask;
+ TLOOP(*dst++ = *src++);
+ } else {
+ /* Copy backwards. Otherwise essentially the same. Alignment works as
+ before, except that it takes (t&wmask) bytes to align, not
+ wsize-(t&wmask). */
+ src += length;
+ dst += length;
+ t = (int) src;
+ if ((t | (int) dst) & wmask) {
+ if ((t ^ (int) dst) & wmask || length <= wsize)
+ t = length;
+ else
+ t &= wmask;
+ length -= t;
+ TLOOP1(*--dst = *--src);
+ }
+ t = length / wsize;
+ TLOOP(src -= wsize;
+ dst -= wsize;
+ *(word *) dst = *(word *) src);
+ t = length & wmask;
+ TLOOP(*--dst = *--src);
+ }
+done:
+ return (dst0);
+}