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 const SoftFloat FLOAT_0 = { 0, MIN_EXP}; ///< 0.0
40 static const SoftFloat FLOAT_05 = { 0x20000000, 0}; ///< 0.5
41 static const SoftFloat FLOAT_1 = { 0x20000000, 1}; ///< 1.0
42 static const SoftFloat FLOAT_EPSILON = { 0x29F16B12, -16}; ///< A small value
43 static const SoftFloat FLOAT_1584893192 = { 0x32B771ED, 1}; ///< 1.584893192 (10^.2)
44 static const SoftFloat FLOAT_100000 = { 0x30D40000, 17}; ///< 100000
45 static const SoftFloat FLOAT_0999999 = { 0x3FFFFBCE, 0}; ///< 0.999999
49 * Convert a SoftFloat to a double precision float.
51 static inline av_const double av_sf2double(SoftFloat v) {
53 return ldexp(v.mant, v.exp);
56 static av_const SoftFloat av_normalize_sf(SoftFloat a){
59 while((a.mant + 0x1FFFFFFFU)<0x3FFFFFFFU){
64 int s=ONE_BITS - av_log2(FFABS(a.mant));
78 static inline av_const SoftFloat av_normalize1_sf(SoftFloat a){
80 if((int32_t)(a.mant + 0x40000000U) <= 0){
84 av_assert2(a.mant < 0x40000000 && a.mant > -0x40000000);
85 av_assert2(a.exp <= MAX_EXP);
88 int t= a.mant + 0x40000000 < 0;
89 return (SoftFloat){ a.mant>>t, a.exp+t};
91 int t= (a.mant + 0x3FFFFFFFU)>>31;
92 return (SoftFloat){a.mant>>t, a.exp+t};
97 * @return Will not be more denormalized than a*b. So if either input is
98 * normalized, then the output will not be worse then the other input.
99 * If both are normalized, then the output will be normalized.
101 static inline av_const SoftFloat av_mul_sf(SoftFloat a, SoftFloat b){
103 av_assert2((int32_t)((a.mant * (int64_t)b.mant) >> ONE_BITS) == (a.mant * (int64_t)b.mant) >> ONE_BITS);
104 a.mant = (a.mant * (int64_t)b.mant) >> ONE_BITS;
105 a = av_normalize1_sf((SoftFloat){a.mant, a.exp - 1});
106 if (!a.mant || a.exp < MIN_EXP)
112 * b has to be normalized and not zero.
113 * @return Will not be more denormalized than a.
115 static inline av_const SoftFloat av_div_sf(SoftFloat a, SoftFloat b){
116 int64_t temp = (int64_t)a.mant * (1<<(ONE_BITS+1));
120 while (a.mant != temp) {
125 a = av_normalize1_sf(a);
126 if (!a.mant || a.exp < MIN_EXP)
132 * Compares two SoftFloats.
133 * @returns < 0 if the first is less
134 * > 0 if the first is greater
135 * 0 if they are equal
137 static inline av_const int av_cmp_sf(SoftFloat a, SoftFloat b){
138 int t= a.exp - b.exp;
139 if (t <-31) return - b.mant ;
140 else if (t < 0) return (a.mant >> (-t)) - b.mant ;
141 else if (t < 32) return a.mant - (b.mant >> t);
146 * Compares two SoftFloats.
147 * @returns 1 if a is greater than b, 0 otherwise
149 static inline av_const int av_gt_sf(SoftFloat a, SoftFloat b)
151 int t= a.exp - b.exp;
152 if (t <-31) return 0 > b.mant ;
153 else if (t < 0) return (a.mant >> (-t)) > b.mant ;
154 else if (t < 32) return a.mant > (b.mant >> t);
155 else return a.mant > 0 ;
159 * @returns the sum of 2 SoftFloats.
161 static inline av_const SoftFloat av_add_sf(SoftFloat a, SoftFloat b){
162 int t= a.exp - b.exp;
163 if (t <-31) return b;
164 else if (t < 0) return av_normalize_sf(av_normalize1_sf((SoftFloat){ b.mant + (a.mant >> (-t)), b.exp}));
165 else if (t < 32) return av_normalize_sf(av_normalize1_sf((SoftFloat){ a.mant + (b.mant >> t ), a.exp}));
170 * @returns the difference of 2 SoftFloats.
172 static inline av_const SoftFloat av_sub_sf(SoftFloat a, SoftFloat b){
173 return av_add_sf(a, (SoftFloat){ -b.mant, b.exp});
176 //FIXME log, exp, pow
179 * Converts a mantisse and exponent to a SoftFloat
180 * @returns a SoftFloat with value v * 2^frac_bits
182 static inline av_const SoftFloat av_int2sf(int v, int frac_bits){
184 if(v <= INT_MIN + 1){
188 return av_normalize_sf(av_normalize1_sf((SoftFloat){v, ONE_BITS + 1 - frac_bits + exp_offset}));
192 * Converts a SoftFloat to an integer.
193 * Rounding is to -inf.
195 static inline av_const int av_sf2int(SoftFloat v, int frac_bits){
196 v.exp += frac_bits - (ONE_BITS + 1);
197 if(v.exp >= 0) return v.mant << v.exp ;
198 else return v.mant >>(-v.exp);
202 * Rounding-to-nearest used.
204 static av_always_inline SoftFloat av_sqrt_sf(SoftFloat val)
210 else if (val.mant < 0)
214 tabIndex = (val.mant - 0x20000000) >> 20;
216 rem = val.mant & 0xFFFFF;
217 val.mant = (int)(((int64_t)av_sqrttbl_sf[tabIndex] * (0x100000 - rem) +
218 (int64_t)av_sqrttbl_sf[tabIndex + 1] * rem +
220 val.mant = (int)(((int64_t)av_sqr_exp_multbl_sf[val.exp & 1] * val.mant +
223 if (val.mant < 0x40000000)
228 val.exp = (val.exp >> 1) + 1;
235 * Rounding-to-nearest used.
237 static av_unused void av_sincos_sf(int a, int *s, int *c)
244 sign = (int32_t)((unsigned)idx << 27) >> 31;
245 cv = av_costbl_1_sf[idx & 0xf];
246 cv = (cv ^ sign) - sign;
249 sign = (int32_t)((unsigned)idx << 27) >> 31;
250 sv = av_costbl_1_sf[idx & 0xf];
251 sv = (sv ^ sign) - sign;
254 ct = av_costbl_2_sf[idx & 0x1f];
255 st = av_sintbl_2_sf[idx & 0x1f];
257 idx = (int)(((int64_t)cv * ct - (int64_t)sv * st + 0x20000000) >> 30);
259 sv = (int)(((int64_t)cv * st + (int64_t)sv * ct + 0x20000000) >> 30);
264 ct = av_costbl_3_sf[idx & 0x1f];
265 st = av_sintbl_3_sf[idx & 0x1f];
267 idx = (int)(((int64_t)cv * ct - (int64_t)sv * st + 0x20000000) >> 30);
269 sv = (int)(((int64_t)cv * st + (int64_t)sv * ct + 0x20000000) >> 30);
274 ct = (int)(((int64_t)av_costbl_4_sf[idx & 0x1f] * (0x800 - (a & 0x7ff)) +
275 (int64_t)av_costbl_4_sf[(idx & 0x1f)+1]*(a & 0x7ff) +
277 st = (int)(((int64_t)av_sintbl_4_sf[idx & 0x1f] * (0x800 - (a & 0x7ff)) +
278 (int64_t)av_sintbl_4_sf[(idx & 0x1f) + 1] * (a & 0x7ff) +
281 *c = (int)(((int64_t)cv * ct + (int64_t)sv * st + 0x20000000) >> 30);
283 *s = (int)(((int64_t)cv * st + (int64_t)sv * ct + 0x20000000) >> 30);
286 #endif /* AVUTIL_SOFTFLOAT_H */