1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25 
  26         .file   "byteorder.s"
  27 
  28 #include <sys/asm_linkage.h>
  29 
  30         /*
  31          * NOTE: htonll/ntohll, htonl/ntohl, and htons/ntohs are identical
  32          * routines. As such, they could be implemented as a single routine,
  33          * using multiple ALTENTRY/SET_SIZE definitions. We don't do this so
  34          * that they will have unique addresses, allowing DTrace and
  35          * other debuggers to tell them apart.
  36          */
  37 
  38 /*
  39  *      unsigned long long htonll( hll )
  40  *      unsigned long long ntohll( hll )
  41  *      unsigned long long hll;
  42  *      reverses the byte order of 'uint64_t hll' on little endian machines
  43  */
  44         ENTRY(htonll)
  45         movq    %rdi, %rax      /* %rax = hll */
  46         bswapq  %rax            /* reverses the byte order of %rax */
  47         ret                     /* return (%rax) */
  48         SET_SIZE(htonll)
  49 
  50         ENTRY(ntohll)
  51         movq    %rdi, %rax      /* %rax = hll */
  52         bswapq  %rax            /* reverses the byte order of %rax */
  53         ret                     /* return (%rax) */
  54         SET_SIZE(ntohll)
  55 
  56 
  57 /*
  58  *      unsigned long htonl( hl )
  59  *      unsigned long ntohl( hl )
  60  *      unsigned long hl;
  61  *      reverses the byte order of 'uint32_t hl' on little endian machines
  62  */
  63         ENTRY(htonl)
  64         movl    %edi, %eax      /* %eax = hl */
  65         bswap   %eax            /* reverses the byte order of %eax */
  66         ret                     /* return (%eax) */
  67         SET_SIZE(htonl)
  68 
  69         ENTRY(ntohl)
  70         movl    %edi, %eax      /* %eax = hl */
  71         bswap   %eax            /* reverses the byte order of %eax */
  72         ret                     /* return (%eax) */
  73         SET_SIZE(ntohl)
  74 
  75 /*
  76  *      unsigned short htons( hs )
  77  *      unsigned short hs;
  78  *      reverses the byte order of 'uint16_t hs' on little endian machines.
  79  */
  80         ENTRY(htons)
  81         movl    %edi, %eax      /* %eax = hs */
  82         bswap   %eax            /* reverses the byte order of %eax */
  83         shrl    $16, %eax       /* moves high 16-bit to low 16-bit */
  84         ret                     /* return (%eax) */
  85         SET_SIZE(htons)
  86 
  87         ENTRY(ntohs)
  88         movl    %edi, %eax      /* %eax = hs */
  89         bswap   %eax            /* reverses the byte order of %eax */
  90         shrl    $16, %eax       /* moves high 16-bit to low 16-bit */
  91         ret                     /* return (%eax) */
  92         SET_SIZE(ntohs)