/*
  * portable IEEE float/double read/write functions
  *
  * Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
  *

  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

  * version 2.1 of the License, or (at your option) any later version.

  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  */

 /**

  * @file

  * portable IEEE float/double read/write functions

  */

 #include <stdint.h>

 #include "mathematics.h"

 #include "intfloat_readwrite.h"

 
 double av_int2dbl(int64_t v){

     if(v+v > 0xFFEULL<<52)

         return NAN;

     return ldexp(((v&((1LL<<52)-1)) + (1LL<<52)) * (v>>63|1), (v>>52&0x7FF)-1075);

 }
 
 float av_int2flt(int32_t v){
     if(v+v > 0xFF000000U)

         return NAN;

     return ldexp(((v&0x7FFFFF) + (1<<23)) * (v>>31|1), (v>>23&0xFF)-150);
 }
 

 double av_ext2dbl(const AVExtFloat ext){
     uint64_t m = 0;
     int e, i;
 
     for (i = 0; i < 8; i++)

         m = (m<<8) + ext.mantissa[i];

     e = (((int)ext.exponent[0]&0x7f)<<8) | ext.exponent[1];
     if (e == 0x7fff && m)

         return NAN;

     e -= 16383 + 63;        /* In IEEE 80 bits, the whole (i.e. 1.xxxx)
                              * mantissa bit is written as opposed to the

                              * single and double precision formats. */

     if (ext.exponent[0]&0x80)

         m= -m;

     return ldexp(m, e);
 }
 

 int64_t av_dbl2int(double d){
     int e;
     if     ( !d) return 0;
     else if(d-d) return 0x7FF0000000000000LL + ((int64_t)(d<0)<<63) + (d!=d);
     d= frexp(d, &e);
     return (int64_t)(d<0)<<63 | (e+1022LL)<<52 | (int64_t)((fabs(d)-0.5)*(1LL<<53));
 }
 
 int32_t av_flt2int(float d){
     int e;
     if     ( !d) return 0;
     else if(d-d) return 0x7F800000 + ((d<0)<<31) + (d!=d);
     d= frexp(d, &e);
     return (d<0)<<31 | (e+126)<<23 | (int64_t)((fabs(d)-0.5)*(1<<24));
 }

 
 AVExtFloat av_dbl2ext(double d){

     struct AVExtFloat ext= {{0}};

     int e, i; double f; uint64_t m;
 
     f = fabs(frexp(d, &e));
     if (f >= 0.5 && f < 1) {
         e += 16382;
         ext.exponent[0] = e>>8;
         ext.exponent[1] = e;
         m = (uint64_t)ldexp(f, 64);
         for (i=0; i < 8; i++)
             ext.mantissa[i] = m>>(56-(i<<3));

     } else if (f != 0.0) {

         ext.exponent[0] = 0x7f; ext.exponent[1] = 0xff;

         if (f != INFINITY)

             ext.mantissa[0] = ~0;
     }
     if (d < 0)
         ext.exponent[0] |= 0x80;
     return ext;
 }