osfmk/i386/commpage/bcopy_scalar.s

   1 /*
   2  * Copyright (c) 2003-2006 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /*-
  30  * Copyright (c) 1990 The Regents of the University of California.
  31  * All rights reserved.
  32  *
  33  * This code is derived from locore.s.
  34  *
  35  * Redistribution and use in source and binary forms, with or without
  36  * modification, are permitted provided that the following conditions
  37  * are met:
  38  * 1. Redistributions of source code must retain the above copyright
  39  *    notice, this list of conditions and the following disclaimer.
  40  * 2. Redistributions in binary form must reproduce the above copyright
  41  *    notice, this list of conditions and the following disclaimer in the
  42  *    documentation and/or other materials provided with the distribution.
  43  * 3. All advertising materials mentioning features or use of this software
  44  *    must display the following acknowledgement:
  45  *      This product includes software developed by the University of
  46  *      California, Berkeley and its contributors.
  47  * 4. Neither the name of the University nor the names of its contributors
  48  *    may be used to endorse or promote products derived from this software
  49  *    without specific prior written permission.
  50  *
  51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  61  * SUCH DAMAGE.
  62  */
  63
  64 #include <sys/appleapiopts.h>
  65 #include <machine/cpu_capabilities.h>
  66 #include <machine/commpage.h>
  67 #include <machine/asm.h>
  68
  69         /*
  70          * (ov)bcopy (src,dst,cnt)
  71          *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
  72          */
  73
  74 COMMPAGE_FUNCTION_START(bcopy_scalar, 32, 5)
  75         pushl   %ebp            /* set up a frame for backtraces */
  76         movl    %esp,%ebp
  77         pushl   %esi
  78         pushl   %edi
  79         movl    8(%ebp),%esi
  80         movl    12(%ebp),%edi
  81         jmp     1f
  82 /*
  83  * These need to be 32 bytes from Lbcopy_scalar
  84  */
  85         .align 5, 0x90
  86 Lmemcpy_scalar:
  87 Lmemmove_scalar:
  88         pushl   %ebp            /* set up a frame for backtraces */
  89         movl    %esp,%ebp
  90         pushl   %esi
  91         pushl   %edi
  92         movl    8(%ebp),%edi
  93         movl    12(%ebp),%esi
  94         movl    %edi,%eax
  95 1:
  96         movl    16(%ebp),%ecx
  97         movl    %edi,%edx
  98         subl    %esi,%edx
  99         cmpl    %ecx,%edx       /* overlapping? */
 100         jb      2f
 101         cld                     /* nope, copy forwards. */
 102         movl    %ecx,%edx
 103         shrl    $2,%ecx         /* copy by words */
 104         rep
 105         movsl
 106         movl    %edx,%ecx
 107         andl    $3,%ecx         /* any bytes left? */
 108         rep
 109         movsb
 110         popl    %edi
 111         popl    %esi
 112         popl    %ebp
 113         ret
 114 2:
 115         addl    %ecx,%edi       /* copy backwards. */
 116         addl    %ecx,%esi
 117         std
 118         movl    %ecx,%edx
 119         andl    $3,%ecx         /* any fractional bytes? */
 120         decl    %edi
 121         decl    %esi
 122         rep
 123         movsb
 124         movl    %edx,%ecx       /* copy remainder by words */
 125         shrl    $2,%ecx
 126         subl    $3,%esi
 127         subl    $3,%edi
 128         rep
 129         movsl
 130         popl    %edi
 131         popl    %esi
 132         popl    %ebp
 133         cld
 134         ret
 135
 136 COMMPAGE_DESCRIPTOR(bcopy_scalar,_COMM_PAGE_BCOPY,0,kHasSSE2+kHasSupplementalSSE3)