2 * portable IEEE float/double read/write functions
4 * Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 * portable IEEE float/double read/write functions
30 #include "mathematics.h"
31 #include "intfloat_readwrite.h"
33 double av_int2dbl(int64_t v){
34 if((uint64_t)v+v > 0xFFEULL<<52)
36 return ldexp(((v&((1LL<<52)-1)) + (1LL<<52)) * (v>>63|1), (v>>52&0x7FF)-1075);
39 float av_int2flt(int32_t v){
40 if((uint32_t)v+v > 0xFF000000U)
42 return ldexp(((v&0x7FFFFF) + (1<<23)) * (v>>31|1), (v>>23&0xFF)-150);
45 double av_ext2dbl(const AVExtFloat ext){
49 for (i = 0; i < 8; i++)
50 m = (m<<8) + ext.mantissa[i];
51 e = (((int)ext.exponent[0]&0x7f)<<8) | ext.exponent[1];
54 e -= 16383 + 63; /* In IEEE 80 bits, the whole (i.e. 1.xxxx)
55 * mantissa bit is written as opposed to the
56 * single and double precision formats. */
57 if (ext.exponent[0]&0x80)
62 int64_t av_dbl2int(double d){
65 else if(d-d) return 0x7FF0000000000000LL + ((int64_t)(d<0)<<63) + (d!=d);
67 return (int64_t)(d<0)<<63 | (e+1022LL)<<52 | (int64_t)((fabs(d)-0.5)*(1LL<<53));
70 int32_t av_flt2int(float d){
73 else if(d-d) return 0x7F800000 + ((d<0)<<31) + (d!=d);
75 return (d<0)<<31 | (e+126)<<23 | (int64_t)((fabs(d)-0.5)*(1<<24));
78 AVExtFloat av_dbl2ext(double d){
79 struct AVExtFloat ext= {{0}};
80 int e, i; double f; uint64_t m;
82 f = fabs(frexp(d, &e));
83 if (f >= 0.5 && f < 1) {
85 ext.exponent[0] = e>>8;
87 m = (uint64_t)ldexp(f, 64);
89 ext.mantissa[i] = m>>(56-(i<<3));
90 } else if (f != 0.0) {
91 ext.exponent[0] = 0x7f; ext.exponent[1] = 0xff;
96 ext.exponent[0] |= 0x80;