mathops.h
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1 /*
2  * simple math operations
3  * Copyright (c) 2001, 2002 Fabrice Bellard
4  * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> et al
5  *
6  * This file is part of Libav.
7  *
8  * Libav 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.
12  *
13  * Libav 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.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 #ifndef AVCODEC_MATHOPS_H
23 #define AVCODEC_MATHOPS_H
24 
25 #include "libavutil/common.h"
26 #include "config.h"
27 
28 #if ARCH_ARM
29 # include "arm/mathops.h"
30 #elif ARCH_AVR32
31 # include "avr32/mathops.h"
32 #elif ARCH_BFIN
33 # include "bfin/mathops.h"
34 #elif ARCH_MIPS
35 # include "mips/mathops.h"
36 #elif ARCH_PPC
37 # include "ppc/mathops.h"
38 #elif ARCH_X86
39 # include "x86/mathops.h"
40 #endif
41 
42 /* generic implementation */
43 
44 #ifndef MUL64
45 # define MUL64(a,b) ((int64_t)(a) * (int64_t)(b))
46 #endif
47 
48 #ifndef MULL
49 # define MULL(a,b,s) (MUL64(a, b) >> (s))
50 #endif
51 
52 #ifndef MULH
53 static av_always_inline int MULH(int a, int b){
54  return MUL64(a, b) >> 32;
55 }
56 #endif
57 
58 #ifndef UMULH
59 static av_always_inline unsigned UMULH(unsigned a, unsigned b){
60  return ((uint64_t)(a) * (uint64_t)(b))>>32;
61 }
62 #endif
63 
64 #ifndef MAC64
65 # define MAC64(d, a, b) ((d) += MUL64(a, b))
66 #endif
67 
68 #ifndef MLS64
69 # define MLS64(d, a, b) ((d) -= MUL64(a, b))
70 #endif
71 
72 /* signed 16x16 -> 32 multiply add accumulate */
73 #ifndef MAC16
74 # define MAC16(rt, ra, rb) rt += (ra) * (rb)
75 #endif
76 
77 /* signed 16x16 -> 32 multiply */
78 #ifndef MUL16
79 # define MUL16(ra, rb) ((ra) * (rb))
80 #endif
81 
82 #ifndef MLS16
83 # define MLS16(rt, ra, rb) ((rt) -= (ra) * (rb))
84 #endif
85 
86 /* median of 3 */
87 #ifndef mid_pred
88 #define mid_pred mid_pred
89 static inline av_const int mid_pred(int a, int b, int c)
90 {
91 #if 0
92  int t= (a-b)&((a-b)>>31);
93  a-=t;
94  b+=t;
95  b-= (b-c)&((b-c)>>31);
96  b+= (a-b)&((a-b)>>31);
97 
98  return b;
99 #else
100  if(a>b){
101  if(c>b){
102  if(c>a) b=a;
103  else b=c;
104  }
105  }else{
106  if(b>c){
107  if(c>a) b=c;
108  else b=a;
109  }
110  }
111  return b;
112 #endif
113 }
114 #endif
115 
116 #ifndef sign_extend
117 static inline av_const int sign_extend(int val, unsigned bits)
118 {
119  unsigned shift = 8 * sizeof(int) - bits;
120  union { unsigned u; int s; } v = { (unsigned) val << shift };
121  return v.s >> shift;
122 }
123 #endif
124 
125 #ifndef zero_extend
126 static inline av_const unsigned zero_extend(unsigned val, unsigned bits)
127 {
128  return (val << ((8 * sizeof(int)) - bits)) >> ((8 * sizeof(int)) - bits);
129 }
130 #endif
131 
132 #ifndef COPY3_IF_LT
133 #define COPY3_IF_LT(x, y, a, b, c, d)\
134 if ((y) < (x)) {\
135  (x) = (y);\
136  (a) = (b);\
137  (c) = (d);\
138 }
139 #endif
140 
141 #ifndef NEG_SSR32
142 # define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s)))
143 #endif
144 
145 #ifndef NEG_USR32
146 # define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))
147 #endif
148 
149 #if HAVE_BIGENDIAN
150 # ifndef PACK_2U8
151 # define PACK_2U8(a,b) (((a) << 8) | (b))
152 # endif
153 # ifndef PACK_4U8
154 # define PACK_4U8(a,b,c,d) (((a) << 24) | ((b) << 16) | ((c) << 8) | (d))
155 # endif
156 # ifndef PACK_2U16
157 # define PACK_2U16(a,b) (((a) << 16) | (b))
158 # endif
159 #else
160 # ifndef PACK_2U8
161 # define PACK_2U8(a,b) (((b) << 8) | (a))
162 # endif
163 # ifndef PACK_4U2
164 # define PACK_4U8(a,b,c,d) (((d) << 24) | ((c) << 16) | ((b) << 8) | (a))
165 # endif
166 # ifndef PACK_2U16
167 # define PACK_2U16(a,b) (((b) << 16) | (a))
168 # endif
169 #endif
170 
171 #ifndef PACK_2S8
172 # define PACK_2S8(a,b) PACK_2U8((a)&255, (b)&255)
173 #endif
174 #ifndef PACK_4S8
175 # define PACK_4S8(a,b,c,d) PACK_4U8((a)&255, (b)&255, (c)&255, (d)&255)
176 #endif
177 #ifndef PACK_2S16
178 # define PACK_2S16(a,b) PACK_2U16((a)&0xffff, (b)&0xffff)
179 #endif
180 
181 #endif /* AVCODEC_MATHOPS_H */
182