diff options
Diffstat (limited to 'lib/libc/i386/string/bcopy.S')
| -rw-r--r-- | lib/libc/i386/string/bcopy.S | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/lib/libc/i386/string/bcopy.S b/lib/libc/i386/string/bcopy.S new file mode 100644 index 0000000..1a3d588 --- /dev/null +++ b/lib/libc/i386/string/bcopy.S @@ -0,0 +1,99 @@ +/*- + * Copyright (c) 1990 The Regents of the University of California. + * All rights reserved. + * + * This code is derived from locore.s. + * + * 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. + * 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. + */ + +#include <machine/asm.h> +__FBSDID("$FreeBSD$"); + +#if 0 + RCSID("$NetBSD: bcopy.S,v 1.6 1996/11/12 00:50:06 jtc Exp $") +#endif + + /* + * (ov)bcopy (src,dst,cnt) + * ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800 + */ + +#ifdef MEMCOPY +ENTRY(memcpy) +#else +#ifdef MEMMOVE +ENTRY(memmove) +#else +ENTRY(bcopy) +#endif +#endif + pushl %esi + pushl %edi +#if defined(MEMCOPY) || defined(MEMMOVE) + movl 12(%esp),%edi + movl 16(%esp),%esi + movl %edi,%eax +#else + movl 12(%esp),%esi + movl 16(%esp),%edi +#endif + movl 20(%esp),%ecx + movl %edi,%edx + subl %esi,%edx + cmpl %ecx,%edx /* overlapping? */ + jb 1f + cld /* nope, copy forwards. */ + movl %ecx,%edx + shrl $2,%ecx /* copy by words */ + rep + movsl + movl %edx,%ecx + andl $3,%ecx /* any bytes left? */ + rep + movsb + popl %edi + popl %esi + ret +1: + addl %ecx,%edi /* copy backwards. */ + addl %ecx,%esi + std + movl %ecx,%edx + andl $3,%ecx /* any fractional bytes? */ + decl %edi + decl %esi + rep + movsb + movl %edx,%ecx /* copy remainder by words */ + shrl $2,%ecx + subl $3,%esi + subl $3,%edi + rep + movsl + popl %edi + popl %esi + cld + ret |
