| The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame^] | 1 | /* $OpenBSD: bcopy.S,v 1.5 2005/08/07 11:30:38 espie Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 1990 The Regents of the University of California. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from locore.s. |
| 8 | * |
| 9 | * Redistribution and use in source and binary forms, with or without |
| 10 | * modification, are permitted provided that the following conditions |
| 11 | * are met: |
| 12 | * 1. Redistributions of source code must retain the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer. |
| 14 | * 2. Redistributions in binary form must reproduce the above copyright |
| 15 | * notice, this list of conditions and the following disclaimer in the |
| 16 | * documentation and/or other materials provided with the distribution. |
| 17 | * 3. Neither the name of the University nor the names of its contributors |
| 18 | * may be used to endorse or promote products derived from this software |
| 19 | * without specific prior written permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 31 | * SUCH DAMAGE. |
| 32 | */ |
| 33 | |
| 34 | #include <machine/asm.h> |
| 35 | |
| 36 | /* |
| 37 | * (ov)bcopy (src,dst,cnt) |
| 38 | * ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800 |
| 39 | */ |
| 40 | |
| 41 | #ifdef MEMCOPY |
| 42 | ENTRY(memcpy) |
| 43 | #else |
| 44 | #ifdef MEMMOVE |
| 45 | ENTRY(memmove) |
| 46 | #else |
| 47 | ENTRY(bcopy) |
| 48 | #endif |
| 49 | #endif |
| 50 | pushl %esi |
| 51 | pushl %edi |
| 52 | #if defined(MEMCOPY) || defined(MEMMOVE) |
| 53 | movl 12(%esp),%edi |
| 54 | movl 16(%esp),%esi |
| 55 | movl %edi, %eax |
| 56 | #else |
| 57 | movl 12(%esp),%esi |
| 58 | movl 16(%esp),%edi |
| 59 | #endif |
| 60 | movl 20(%esp),%ecx |
| 61 | movl %ecx,%edx |
| 62 | cmpl %esi,%edi /* potentially overlapping? */ |
| 63 | jnb 1f |
| 64 | cld /* nope, copy forwards. */ |
| 65 | shrl $2,%ecx /* copy by words */ |
| 66 | rep |
| 67 | movsl |
| 68 | movl %edx,%ecx |
| 69 | andl $3,%ecx /* any bytes left? */ |
| 70 | rep |
| 71 | movsb |
| 72 | popl %edi |
| 73 | popl %esi |
| 74 | ret |
| 75 | 1: |
| 76 | addl %ecx,%edi /* copy backwards. */ |
| 77 | addl %ecx,%esi |
| 78 | std |
| 79 | andl $3,%ecx /* any fractional bytes? */ |
| 80 | decl %edi |
| 81 | decl %esi |
| 82 | rep |
| 83 | movsb |
| 84 | movl %edx,%ecx |
| 85 | shrl $2,%ecx |
| 86 | subl $3,%esi |
| 87 | subl $3,%edi |
| 88 | rep |
| 89 | movsl |
| 90 | popl %edi |
| 91 | popl %esi |
| 92 | cld |
| 93 | ret |