usr/src/lib/libc/port/gen/lmath.c

   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 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 /*
  33  * This set of routines used to be implemented mostly in assembler.
  34  *
  35  * Since the purpose they have is now rather vestigial, and 64-bit
  36  * machines can do operations on 64-bit quantities pretty efficiently,
  37  * a C implementation seems quite adequate and much more maintainable.
  38  */
  39
  40 #include "lint.h"
  41 #include <sys/types.h>
  42 #include <sys/dl.h>
  43
  44 typedef union {
  45         long    xword;
  46         dl_t    dl;
  47 } dlx_t;
  48
  49 dl_t
  50 ladd(dl_t lop, dl_t rop)
  51 {
  52         dlx_t r;
  53         /* LINTED pointer cast may result in improper alignment */
  54         r.xword = *(long *)&lop + *(long *)&rop;
  55         return (r.dl);
  56 }
  57
  58 dl_t
  59 lshiftl(dl_t op, int cnt)
  60 {
  61         dlx_t r;
  62         if (cnt < 0)
  63                 /* LINTED pointer cast may result in improper alignment */
  64                 r.xword = (long)(*(ulong_t *)&op >> (-cnt));
  65         else
  66                 /* LINTED pointer cast may result in improper alignment */
  67                 r.xword = *(long *)&op << cnt;
  68         return (r.dl);
  69 }
  70
  71 int
  72 lsign(dl_t op)
  73 {
  74         /* LINTED pointer cast may result in improper alignment */
  75         return ((*(long *)&op) >> 63);
  76 }
  77
  78 dl_t
  79 lsub(dl_t lop, dl_t rop)
  80 {
  81         dlx_t r;
  82         /* LINTED pointer cast may result in improper alignment */
  83         r.xword = *(long *)&lop - *(long *)&rop;
  84         return (r.dl);
  85 }
  86
  87 dl_t
  88 lmul(dl_t lop, dl_t rop)
  89 {
  90         dlx_t r;
  91         /* LINTED pointer cast may result in improper alignment */
  92         r.xword = *(long *)&lop * *(long *)&rop;
  93         return (r.dl);
  94 }