FFmpeg
integer.c
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1 /*
2  * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
3  *
4  * This file is part of FFmpeg.
5  *
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.
10  *
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.
15  *
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
19  */
20 
21 #include <stdint.h>
22 
23 #include "libavutil/avassert.h"
24 #include "libavutil/integer.h"
25 #include "libavutil/intmath.h"
26 
27 int main(void){
28  int64_t a,b;
29 
30  for(a=7; a<256*256*256; a+=13215){
31  for(b=3; b<256*256*256; b+=27118){
32  AVInteger ai= av_int2i(a);
33  AVInteger bi= av_int2i(b);
34 
35  av_assert0(av_i2int(ai) == a);
36  av_assert0(av_i2int(bi) == b);
37  av_assert0(av_i2int(av_add_i(ai,bi)) == a+b);
38  av_assert0(av_i2int(av_sub_i(ai,bi)) == a-b);
39  av_assert0(av_i2int(av_mul_i(ai,bi)) == a*b);
40  av_assert0(av_i2int(av_shr_i(ai, 9)) == a>>9);
41  av_assert0(av_i2int(av_shr_i(ai,-9)) == a<<9);
42  av_assert0(av_i2int(av_shr_i(ai, 17)) == a>>17);
43  av_assert0(av_i2int(av_shr_i(ai,-17)) == a<<17);
44  av_assert0(av_log2_i(ai) == av_log2(a));
45  av_assert0(av_i2int(av_div_i(ai,bi)) == a/b);
46  }
47  }
48  return 0;
49 }
int main(void)
Definition: integer.c:27
int av_log2(unsigned v)
Definition: intmath.c:26
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:36
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
int64_t av_i2int(AVInteger a)
Convert the given AVInteger to an int64_t.
Definition: integer.c:158
AVInteger av_int2i(int64_t a)
Convert the given int64_t to an AVInteger.
Definition: integer.c:147
int av_log2_i(AVInteger a)
Return the rounded-down value of the base 2 logarithm of the given AVInteger.
Definition: integer.c:54
AVInteger av_mul_i(AVInteger a, AVInteger b)
Definition: integer.c:64
simple assert() macros that are a bit more flexible than ISO C assert().
#define b
Definition: input.c:41
AVInteger av_add_i(AVInteger a, AVInteger b)
Definition: integer.c:34
AVInteger av_sub_i(AVInteger a, AVInteger b)
Definition: integer.c:44
AVInteger av_shr_i(AVInteger a, int s)
bitwise shift
Definition: integer.c:97
arbitrary precision integers
AVInteger av_div_i(AVInteger a, AVInteger b)
Return a/b.
Definition: integer.c:141