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string/FreeBSD/bcopy.c /dev/null Libc-320
--- /dev/null
+++ Libc/Libc-320/string/FreeBSD/bcopy.c
@@ -0,0 +1,139 @@
+/*-
+ * 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>
+__FBSDID("$FreeBSD: src/lib/libc/string/bcopy.c,v 1.5 2002/09/01 21:53:46 robert Exp $");
+
+/*
+ * 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.
+ */
+#if defined(MEMCOPY) || defined(MEMMOVE)
+#include <string.h>
+
+void *
+#ifdef MEMCOPY
+memcpy
+#else
+memmove
+#endif
+(void *dst0, const void *src0, size_t length)
+#else
+#include <strings.h>
+
+void
+bcopy(const void *src0, void *dst0, size_t length)
+#endif
+{
+	char *dst = dst0;
+	const char *src = src0;
+	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:
+#if defined(MEMCOPY) || defined(MEMMOVE)
+	return (dst0);
+#else
+	return;
+#endif
+}