| /* $OpenBSD: bcopy.S,v 1.5 2005/08/07 11:30:38 espie Exp $ */ |
| |
| /*- |
| * 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. |
| * 3. 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> |
| |
| /* |
| * (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 %ecx,%edx |
| cmpl %esi,%edi /* potentially overlapping? */ |
| jnb 1f |
| cld /* nope, copy forwards. */ |
| 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 |
| andl $3,%ecx /* any fractional bytes? */ |
| decl %edi |
| decl %esi |
| rep |
| movsb |
| movl %edx,%ecx |
| shrl $2,%ecx |
| subl $3,%esi |
| subl $3,%edi |
| rep |
| movsl |
| popl %edi |
| popl %esi |
| cld |
| ret |