2 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 #ifndef AVUTIL_SOFTFLOAT_H
22 #define AVUTIL_SOFTFLOAT_H
28 #include "softfloat_tables.h"
34 typedef struct SoftFloat{
39 static inline av_const double av_sf2double(SoftFloat v) {
41 if(v.exp > 0) return (double)v.mant * (double)(1 << v.exp);
42 else return (double)v.mant / (double)(1 << (-v.exp));
45 static av_const SoftFloat av_normalize_sf(SoftFloat a){
48 while((a.mant + 0x1FFFFFFFU)<0x3FFFFFFFU){
53 int s=ONE_BITS - av_log2(FFABS(a.mant));
67 static inline av_const SoftFloat av_normalize1_sf(SoftFloat a){
69 if((int32_t)(a.mant + 0x40000000U) <= 0){
73 av_assert2(a.mant < 0x40000000 && a.mant > -0x40000000);
76 int t= a.mant + 0x40000000 < 0;
77 return (SoftFloat){ a.mant>>t, a.exp+t};
79 int t= (a.mant + 0x3FFFFFFFU)>>31;
80 return (SoftFloat){a.mant>>t, a.exp+t};
85 * @return Will not be more denormalized than a+b. So if either input is
86 * normalized, then the output will not be worse then the other input.
87 * If both are normalized, then the output will be normalized.
89 static inline av_const SoftFloat av_mul_sf(SoftFloat a, SoftFloat b){
91 av_assert2((int32_t)((a.mant * (int64_t)b.mant) >> ONE_BITS) == (a.mant * (int64_t)b.mant) >> ONE_BITS);
92 a.mant = (a.mant * (int64_t)b.mant) >> ONE_BITS;
93 return av_normalize1_sf((SoftFloat){a.mant, a.exp - 1});
97 * b has to be normalized and not zero.
98 * @return Will not be more denormalized than a.
100 static inline av_const SoftFloat av_div_sf(SoftFloat a, SoftFloat b){
102 a.mant = ((int64_t)a.mant<<(ONE_BITS+1)) / b.mant;
103 return av_normalize1_sf(a);
106 static inline av_const int av_cmp_sf(SoftFloat a, SoftFloat b){
107 int t= a.exp - b.exp;
108 if(t<0) return (a.mant >> (-t)) - b.mant ;
109 else return a.mant - (b.mant >> t);
112 static inline av_const int av_gt_sf(SoftFloat a, SoftFloat b)
114 int t= a.exp - b.exp;
115 if(t<0) return (a.mant >> (-t)) > b.mant ;
116 else return a.mant > (b.mant >> t);
119 static inline av_const SoftFloat av_add_sf(SoftFloat a, SoftFloat b){
120 int t= a.exp - b.exp;
121 if (t <-31) return b;
122 else if (t < 0) return av_normalize_sf(av_normalize1_sf((SoftFloat){ b.mant + (a.mant >> (-t)), b.exp}));
123 else if (t < 32) return av_normalize_sf(av_normalize1_sf((SoftFloat){ a.mant + (b.mant >> t ), a.exp}));
127 static inline av_const SoftFloat av_sub_sf(SoftFloat a, SoftFloat b){
128 return av_add_sf(a, (SoftFloat){ -b.mant, b.exp});
131 //FIXME log, exp, pow
134 * Converts a mantisse and exponent to a SoftFloat
135 * @returns a SoftFloat with value v * 2^frac_bits
137 static inline av_const SoftFloat av_int2sf(int v, int frac_bits){
138 return av_normalize_sf((SoftFloat){v, ONE_BITS + 1 - frac_bits});
142 * Rounding is to -inf.
144 static inline av_const int av_sf2int(SoftFloat v, int frac_bits){
145 v.exp += frac_bits - (ONE_BITS + 1);
146 if(v.exp >= 0) return v.mant << v.exp ;
147 else return v.mant >>(-v.exp);
151 * Rounding-to-nearest used.
153 static av_always_inline SoftFloat av_sqrt_sf(SoftFloat val)
161 tabIndex = (val.mant - 0x20000000) >> 20;
163 rem = val.mant & 0xFFFFF;
164 val.mant = (int)(((int64_t)av_sqrttbl_sf[tabIndex] * (0x100000 - rem) +
165 (int64_t)av_sqrttbl_sf[tabIndex + 1] * rem +
167 val.mant = (int)(((int64_t)av_sqr_exp_multbl_sf[val.exp & 1] * val.mant +
170 if (val.mant < 0x40000000)
175 val.exp = (val.exp >> 1) + 1;
182 * Rounding-to-nearest used.
184 void av_sincos_sf(int a, int *s, int *c);
186 #endif /* AVUTIL_SOFTFLOAT_H */