diff options
Diffstat (limited to 'lib/libc/i386/string/memmove.S')
| -rw-r--r-- | lib/libc/i386/string/memmove.S | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/lib/libc/i386/string/memmove.S b/lib/libc/i386/string/memmove.S new file mode 100644 index 0000000..7eeec5b --- /dev/null +++ b/lib/libc/i386/string/memmove.S @@ -0,0 +1,89 @@ +/*- + * Copyright (c) 1990 The Regents of the University of California. + * All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * + * 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. + * + * $Id: memmove.S,v 1.2 1994/03/31 14:11:00 davidg Exp $ + */ + +#if defined(LIBC_RCS) && !defined(lint) + .asciz "$Id: memmove.S,v 1.2 1994/03/31 14:11:00 davidg Exp $" +#endif /* LIBC_RCS and not lint */ + +#include "DEFS.h" + + /* + * (ov)bcopy (src,dst,cnt) + * ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800 + */ + +ALTENTRY(memcpy) +ENTRY(memmove) + pushl %esi + pushl %edi + movl 12(%esp),%edi + movl 16(%esp),%esi + movl 20(%esp),%ecx + cmpl %esi,%edi /* potentially overlapping? */ + jnb 1f + cld /* nope, copy forwards. */ + shrl $2,%ecx /* copy by words */ + rep + movsl + movl 20(%esp),%ecx + andl $3,%ecx /* any bytes left? */ + rep + movsb + movl 12(%esp),%eax + popl %edi + popl %esi + ret +1: + addl %ecx,%edi /* copy backwards. */ + addl %ecx,%esi + std + andl $3,%ecx /* any fractional bytes? */ + decl %edi + decl %esi + rep + movsb + movl 20(%esp),%ecx /* copy remainder by words */ + shrl $2,%ecx + subl $3,%esi + subl $3,%edi + rep + movsl + movl 12(%esp),%eax + popl %edi + popl %esi + cld + ret |
