Move all definitions of FLAC__U64L to one place.
[flac.git] / src / libFLAC / float.c
1 /* libFLAC - Free Lossless Audio Codec library
2  * Copyright (C) 2004,2005,2006,2007,2008,2009  Josh Coalson
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * - Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  *
11  * - Redistributions in binary form must reproduce the above copyright
12  * notice, this list of conditions and the following disclaimer in the
13  * documentation and/or other materials provided with the distribution.
14  *
15  * - Neither the name of the Xiph.org Foundation nor the names of its
16  * contributors may be used to endorse or promote products derived from
17  * this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31
32 #if HAVE_CONFIG_H
33 #  include <config.h>
34 #endif
35
36 #include "FLAC/assert.h"
37 #include "share/compat.h"
38 #include "private/float.h"
39
40 #ifdef FLAC__INTEGER_ONLY_LIBRARY
41
42 const FLAC__fixedpoint FLAC__FP_ZERO = 0;
43 const FLAC__fixedpoint FLAC__FP_ONE_HALF = 0x00008000;
44 const FLAC__fixedpoint FLAC__FP_ONE = 0x00010000;
45 const FLAC__fixedpoint FLAC__FP_LN2 = 45426;
46 const FLAC__fixedpoint FLAC__FP_E = 178145;
47
48 /* Lookup tables for Knuth's logarithm algorithm */
49 #define LOG2_LOOKUP_PRECISION 16
50 static const FLAC__uint32 log2_lookup[][LOG2_LOOKUP_PRECISION] = {
51         {
52                 /*
53                  * 0 fraction bits
54                  */
55                 /* undefined */ 0x00000000,
56                 /* lg(2/1) = */ 0x00000001,
57                 /* lg(4/3) = */ 0x00000000,
58                 /* lg(8/7) = */ 0x00000000,
59                 /* lg(16/15) = */ 0x00000000,
60                 /* lg(32/31) = */ 0x00000000,
61                 /* lg(64/63) = */ 0x00000000,
62                 /* lg(128/127) = */ 0x00000000,
63                 /* lg(256/255) = */ 0x00000000,
64                 /* lg(512/511) = */ 0x00000000,
65                 /* lg(1024/1023) = */ 0x00000000,
66                 /* lg(2048/2047) = */ 0x00000000,
67                 /* lg(4096/4095) = */ 0x00000000,
68                 /* lg(8192/8191) = */ 0x00000000,
69                 /* lg(16384/16383) = */ 0x00000000,
70                 /* lg(32768/32767) = */ 0x00000000
71         },
72         {
73                 /*
74                  * 4 fraction bits
75                  */
76                 /* undefined */ 0x00000000,
77                 /* lg(2/1) = */ 0x00000010,
78                 /* lg(4/3) = */ 0x00000007,
79                 /* lg(8/7) = */ 0x00000003,
80                 /* lg(16/15) = */ 0x00000001,
81                 /* lg(32/31) = */ 0x00000001,
82                 /* lg(64/63) = */ 0x00000000,
83                 /* lg(128/127) = */ 0x00000000,
84                 /* lg(256/255) = */ 0x00000000,
85                 /* lg(512/511) = */ 0x00000000,
86                 /* lg(1024/1023) = */ 0x00000000,
87                 /* lg(2048/2047) = */ 0x00000000,
88                 /* lg(4096/4095) = */ 0x00000000,
89                 /* lg(8192/8191) = */ 0x00000000,
90                 /* lg(16384/16383) = */ 0x00000000,
91                 /* lg(32768/32767) = */ 0x00000000
92         },
93         {
94                 /*
95                  * 8 fraction bits
96                  */
97                 /* undefined */ 0x00000000,
98                 /* lg(2/1) = */ 0x00000100,
99                 /* lg(4/3) = */ 0x0000006a,
100                 /* lg(8/7) = */ 0x00000031,
101                 /* lg(16/15) = */ 0x00000018,
102                 /* lg(32/31) = */ 0x0000000c,
103                 /* lg(64/63) = */ 0x00000006,
104                 /* lg(128/127) = */ 0x00000003,
105                 /* lg(256/255) = */ 0x00000001,
106                 /* lg(512/511) = */ 0x00000001,
107                 /* lg(1024/1023) = */ 0x00000000,
108                 /* lg(2048/2047) = */ 0x00000000,
109                 /* lg(4096/4095) = */ 0x00000000,
110                 /* lg(8192/8191) = */ 0x00000000,
111                 /* lg(16384/16383) = */ 0x00000000,
112                 /* lg(32768/32767) = */ 0x00000000
113         },
114         {
115                 /*
116                  * 12 fraction bits
117                  */
118                 /* undefined */ 0x00000000,
119                 /* lg(2/1) = */ 0x00001000,
120                 /* lg(4/3) = */ 0x000006a4,
121                 /* lg(8/7) = */ 0x00000315,
122                 /* lg(16/15) = */ 0x0000017d,
123                 /* lg(32/31) = */ 0x000000bc,
124                 /* lg(64/63) = */ 0x0000005d,
125                 /* lg(128/127) = */ 0x0000002e,
126                 /* lg(256/255) = */ 0x00000017,
127                 /* lg(512/511) = */ 0x0000000c,
128                 /* lg(1024/1023) = */ 0x00000006,
129                 /* lg(2048/2047) = */ 0x00000003,
130                 /* lg(4096/4095) = */ 0x00000001,
131                 /* lg(8192/8191) = */ 0x00000001,
132                 /* lg(16384/16383) = */ 0x00000000,
133                 /* lg(32768/32767) = */ 0x00000000
134         },
135         {
136                 /*
137                  * 16 fraction bits
138                  */
139                 /* undefined */ 0x00000000,
140                 /* lg(2/1) = */ 0x00010000,
141                 /* lg(4/3) = */ 0x00006a40,
142                 /* lg(8/7) = */ 0x00003151,
143                 /* lg(16/15) = */ 0x000017d6,
144                 /* lg(32/31) = */ 0x00000bba,
145                 /* lg(64/63) = */ 0x000005d1,
146                 /* lg(128/127) = */ 0x000002e6,
147                 /* lg(256/255) = */ 0x00000172,
148                 /* lg(512/511) = */ 0x000000b9,
149                 /* lg(1024/1023) = */ 0x0000005c,
150                 /* lg(2048/2047) = */ 0x0000002e,
151                 /* lg(4096/4095) = */ 0x00000017,
152                 /* lg(8192/8191) = */ 0x0000000c,
153                 /* lg(16384/16383) = */ 0x00000006,
154                 /* lg(32768/32767) = */ 0x00000003
155         },
156         {
157                 /*
158                  * 20 fraction bits
159                  */
160                 /* undefined */ 0x00000000,
161                 /* lg(2/1) = */ 0x00100000,
162                 /* lg(4/3) = */ 0x0006a3fe,
163                 /* lg(8/7) = */ 0x00031513,
164                 /* lg(16/15) = */ 0x00017d60,
165                 /* lg(32/31) = */ 0x0000bb9d,
166                 /* lg(64/63) = */ 0x00005d10,
167                 /* lg(128/127) = */ 0x00002e59,
168                 /* lg(256/255) = */ 0x00001721,
169                 /* lg(512/511) = */ 0x00000b8e,
170                 /* lg(1024/1023) = */ 0x000005c6,
171                 /* lg(2048/2047) = */ 0x000002e3,
172                 /* lg(4096/4095) = */ 0x00000171,
173                 /* lg(8192/8191) = */ 0x000000b9,
174                 /* lg(16384/16383) = */ 0x0000005c,
175                 /* lg(32768/32767) = */ 0x0000002e
176         },
177         {
178                 /*
179                  * 24 fraction bits
180                  */
181                 /* undefined */ 0x00000000,
182                 /* lg(2/1) = */ 0x01000000,
183                 /* lg(4/3) = */ 0x006a3fe6,
184                 /* lg(8/7) = */ 0x00315130,
185                 /* lg(16/15) = */ 0x0017d605,
186                 /* lg(32/31) = */ 0x000bb9ca,
187                 /* lg(64/63) = */ 0x0005d0fc,
188                 /* lg(128/127) = */ 0x0002e58f,
189                 /* lg(256/255) = */ 0x0001720e,
190                 /* lg(512/511) = */ 0x0000b8d8,
191                 /* lg(1024/1023) = */ 0x00005c61,
192                 /* lg(2048/2047) = */ 0x00002e2d,
193                 /* lg(4096/4095) = */ 0x00001716,
194                 /* lg(8192/8191) = */ 0x00000b8b,
195                 /* lg(16384/16383) = */ 0x000005c5,
196                 /* lg(32768/32767) = */ 0x000002e3
197         },
198         {
199                 /*
200                  * 28 fraction bits
201                  */
202                 /* undefined */ 0x00000000,
203                 /* lg(2/1) = */ 0x10000000,
204                 /* lg(4/3) = */ 0x06a3fe5c,
205                 /* lg(8/7) = */ 0x03151301,
206                 /* lg(16/15) = */ 0x017d6049,
207                 /* lg(32/31) = */ 0x00bb9ca6,
208                 /* lg(64/63) = */ 0x005d0fba,
209                 /* lg(128/127) = */ 0x002e58f7,
210                 /* lg(256/255) = */ 0x001720da,
211                 /* lg(512/511) = */ 0x000b8d87,
212                 /* lg(1024/1023) = */ 0x0005c60b,
213                 /* lg(2048/2047) = */ 0x0002e2d7,
214                 /* lg(4096/4095) = */ 0x00017160,
215                 /* lg(8192/8191) = */ 0x0000b8ad,
216                 /* lg(16384/16383) = */ 0x00005c56,
217                 /* lg(32768/32767) = */ 0x00002e2b
218         }
219 };
220
221 #if 0
222 static const FLAC__uint64 log2_lookup_wide[] = {
223         {
224                 /*
225                  * 32 fraction bits
226                  */
227                 /* undefined */ 0x00000000,
228                 /* lg(2/1) = */ FLAC__U64L(0x100000000),
229                 /* lg(4/3) = */ FLAC__U64L(0x6a3fe5c6),
230                 /* lg(8/7) = */ FLAC__U64L(0x31513015),
231                 /* lg(16/15) = */ FLAC__U64L(0x17d60497),
232                 /* lg(32/31) = */ FLAC__U64L(0x0bb9ca65),
233                 /* lg(64/63) = */ FLAC__U64L(0x05d0fba2),
234                 /* lg(128/127) = */ FLAC__U64L(0x02e58f74),
235                 /* lg(256/255) = */ FLAC__U64L(0x01720d9c),
236                 /* lg(512/511) = */ FLAC__U64L(0x00b8d875),
237                 /* lg(1024/1023) = */ FLAC__U64L(0x005c60aa),
238                 /* lg(2048/2047) = */ FLAC__U64L(0x002e2d72),
239                 /* lg(4096/4095) = */ FLAC__U64L(0x00171600),
240                 /* lg(8192/8191) = */ FLAC__U64L(0x000b8ad2),
241                 /* lg(16384/16383) = */ FLAC__U64L(0x0005c55d),
242                 /* lg(32768/32767) = */ FLAC__U64L(0x0002e2ac)
243         },
244         {
245                 /*
246                  * 48 fraction bits
247                  */
248                 /* undefined */ 0x00000000,
249                 /* lg(2/1) = */ FLAC__U64L(0x1000000000000),
250                 /* lg(4/3) = */ FLAC__U64L(0x6a3fe5c60429),
251                 /* lg(8/7) = */ FLAC__U64L(0x315130157f7a),
252                 /* lg(16/15) = */ FLAC__U64L(0x17d60496cfbb),
253                 /* lg(32/31) = */ FLAC__U64L(0xbb9ca64ecac),
254                 /* lg(64/63) = */ FLAC__U64L(0x5d0fba187cd),
255                 /* lg(128/127) = */ FLAC__U64L(0x2e58f7441ee),
256                 /* lg(256/255) = */ FLAC__U64L(0x1720d9c06a8),
257                 /* lg(512/511) = */ FLAC__U64L(0xb8d8752173),
258                 /* lg(1024/1023) = */ FLAC__U64L(0x5c60aa252e),
259                 /* lg(2048/2047) = */ FLAC__U64L(0x2e2d71b0d8),
260                 /* lg(4096/4095) = */ FLAC__U64L(0x1716001719),
261                 /* lg(8192/8191) = */ FLAC__U64L(0xb8ad1de1b),
262                 /* lg(16384/16383) = */ FLAC__U64L(0x5c55d640d),
263                 /* lg(32768/32767) = */ FLAC__U64L(0x2e2abcf52)
264         }
265 };
266 #endif
267
268 FLAC__uint32 FLAC__fixedpoint_log2(FLAC__uint32 x, unsigned fracbits, unsigned precision)
269 {
270         const FLAC__uint32 ONE = (1u << fracbits);
271         const FLAC__uint32 *table = log2_lookup[fracbits >> 2];
272
273         FLAC__ASSERT(fracbits < 32);
274         FLAC__ASSERT((fracbits & 0x3) == 0);
275
276         if(x < ONE)
277                 return 0;
278
279         if(precision > LOG2_LOOKUP_PRECISION)
280                 precision = LOG2_LOOKUP_PRECISION;
281
282         /* Knuth's algorithm for computing logarithms, optimized for base-2 with lookup tables */
283         {
284                 FLAC__uint32 y = 0;
285                 FLAC__uint32 z = x >> 1, k = 1;
286                 while (x > ONE && k < precision) {
287                         if (x - z >= ONE) {
288                                 x -= z;
289                                 z = x >> k;
290                                 y += table[k];
291                         }
292                         else {
293                                 z >>= 1;
294                                 k++;
295                         }
296                 }
297                 return y;
298         }
299 }
300
301 #endif /* defined FLAC__INTEGER_ONLY_LIBRARY */