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       1                 :             : /*-
       2                 :             :  * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
       3                 :             :  * All rights reserved.
       4                 :             :  *
       5                 :             :  * Redistribution and use in source and binary forms, with or without
       6                 :             :  * modification, are permitted provided that the following conditions
       7                 :             :  * are met:
       8                 :             :  * 1. Redistributions of source code must retain the above copyright
       9                 :             :  *    notice, this list of conditions and the following disclaimer.
      10                 :             :  * 2. Redistributions in binary form must reproduce the above copyright
      11                 :             :  *    notice, this list of conditions and the following disclaimer in the
      12                 :             :  *    documentation and/or other materials provided with the distribution.
      13                 :             :  *
      14                 :             :  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
      15                 :             :  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      16                 :             :  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
      17                 :             :  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
      18                 :             :  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
      19                 :             :  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
      20                 :             :  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      21                 :             :  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
      22                 :             :  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
      23                 :             :  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
      24                 :             :  * SUCH DAMAGE.
      25                 :             :  *
      26                 :             :  * $FreeBSD: src/lib/msun/src/s_frexpl.c,v 1.1 2005/03/07 04:54:51 das Exp $
      27                 :             :  */
      28                 :             : 
      29                 :             : #include <float.h>
      30                 :             : #include <openlibm_math.h>
      31                 :             : 
      32                 :             : #include "fpmath.h"
      33                 :             : #include "math_private.h"
      34                 :             : 
      35                 :             : #if LDBL_MAX_EXP != 0x4000
      36                 :             : #error "Unsupported long double format"
      37                 :             : #endif
      38                 :             : 
      39                 :             : OLM_DLLEXPORT long double
      40                 :           0 : frexpl(long double x, int *ex)
      41                 :             : {
      42                 :             :         union IEEEl2bits u;
      43                 :             : 
      44                 :           0 :         u.e = x;
      45      [ #  #  # ]:           0 :         switch (u.bits.exp) {
      46                 :           0 :         case 0:         /* 0 or subnormal */
      47         [ #  # ]:           0 :                 if ((u.bits.manl | u.bits.manh) == 0) {
      48                 :           0 :                         *ex = 0;
      49                 :             :                 } else {
      50                 :           0 :                         u.e *= 0x1.0p514;
      51                 :           0 :                         *ex = u.bits.exp - 0x4200;
      52                 :           0 :                         u.bits.exp = 0x3ffe;
      53                 :             :                 }
      54                 :           0 :                 break;
      55                 :           0 :         case 0x7fff:    /* infinity or NaN; value of *ex is unspecified */
      56                 :           0 :                 break;
      57                 :           0 :         default:        /* normal */
      58                 :           0 :                 *ex = u.bits.exp - 0x3ffe;
      59                 :           0 :                 u.bits.exp = 0x3ffe;
      60                 :           0 :                 break;
      61                 :             :         }
      62                 :           0 :         return (u.e);
      63                 :             : }