FFmpeg
cabac.h
Go to the documentation of this file.
1 /*
2  * Loongson optimized cabac
3  *
4  * Copyright (c) 2020 Loongson Technology Corporation Limited
5  * Contributed by Shiyou Yin <yinshiyou-hf@loongson.cn>
6  * Gu Xiwei(guxiwei-hf@loongson.cn)
7  *
8  * This file is part of FFmpeg.
9  *
10  * FFmpeg is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU Lesser General Public
12  * License as published by the Free Software Foundation; either
13  * version 2.1 of the License, or (at your option) any later version.
14  *
15  * FFmpeg is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18  * Lesser General Public License for more details.
19  *
20  * You should have received a copy of the GNU Lesser General Public
21  * License along with FFmpeg; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23  */
24 
25 #ifndef AVCODEC_LOONGARCH_CABAC_H
26 #define AVCODEC_LOONGARCH_CABAC_H
27 
28 #include "libavcodec/cabac.h"
29 #include "config.h"
30 
31 #define GET_CABAC_LOONGARCH_UNCBSR \
32  "ld.bu %[bit], %[state], 0x0 \n\t" \
33  "andi %[tmp0], %[c_range], 0xC0 \n\t" \
34  "slli.d %[tmp0], %[tmp0], 0x01 \n\t" \
35  "add.d %[tmp0], %[tmp0], %[tables] \n\t" \
36  "add.d %[tmp0], %[tmp0], %[bit] \n\t" \
37  /* tmp1: RangeLPS */ \
38  "ld.bu %[tmp1], %[tmp0], %[lps_off] \n\t" \
39  \
40  "sub.d %[c_range], %[c_range], %[tmp1] \n\t" \
41  "slli.d %[tmp0], %[c_range], 0x11 \n\t" \
42  "bge %[tmp0], %[c_low], 1f \n\t" \
43  "move %[c_range], %[tmp1] \n\t" \
44  "nor %[bit], %[bit], %[bit] \n\t" \
45  "sub.d %[c_low], %[c_low], %[tmp0] \n\t" \
46  \
47  "1: \n\t" \
48  /* tmp1: *state */ \
49  "add.d %[tmp0], %[tables], %[bit] \n\t" \
50  "ld.bu %[tmp1], %[tmp0], %[mlps_off] \n\t" \
51  /* tmp2: lps_mask */ \
52  "add.d %[tmp0], %[tables], %[c_range] \n\t" \
53  "ld.bu %[tmp2], %[tmp0], %[norm_off] \n\t" \
54  \
55  "andi %[bit], %[bit], 0x01 \n\t" \
56  "st.b %[tmp1], %[state], 0x0 \n\t" \
57  "sll.d %[c_range], %[c_range], %[tmp2] \n\t" \
58  "sll.d %[c_low], %[c_low], %[tmp2] \n\t" \
59  \
60  "and %[tmp1], %[c_low], %[cabac_mask] \n\t" \
61  "bnez %[tmp1], 1f \n\t" \
62  "ld.hu %[tmp1], %[c_bytestream], 0x0 \n\t" \
63  "ctz.d %[tmp0], %[c_low] \n\t" \
64  "addi.d %[tmp2], %[tmp0], -16 \n\t" \
65  "revb.2h %[tmp0], %[tmp1] \n\t" \
66  "slli.d %[tmp0], %[tmp0], 0x01 \n\t" \
67  "sub.d %[tmp0], %[tmp0], %[cabac_mask] \n\t" \
68  "sll.d %[tmp0], %[tmp0], %[tmp2] \n\t" \
69  "add.d %[c_low], %[c_low], %[tmp0] \n\t" \
70  "addi.d %[c_bytestream], %[c_bytestream], 0x02 \n\t" \
71  "1: \n\t" \
72 
73 #define GET_CABAC_LOONGARCH \
74  "ld.bu %[bit], %[state], 0x0 \n\t" \
75  "andi %[tmp0], %[c_range], 0xC0 \n\t" \
76  "slli.d %[tmp0], %[tmp0], 0x01 \n\t" \
77  "add.d %[tmp0], %[tmp0], %[tables] \n\t" \
78  "add.d %[tmp0], %[tmp0], %[bit] \n\t" \
79  /* tmp1: RangeLPS */ \
80  "ld.bu %[tmp1], %[tmp0], %[lps_off] \n\t" \
81  \
82  "sub.d %[c_range], %[c_range], %[tmp1] \n\t" \
83  "slli.d %[tmp0], %[c_range], 0x11 \n\t" \
84  "bge %[tmp0], %[c_low], 1f \n\t" \
85  "move %[c_range], %[tmp1] \n\t" \
86  "nor %[bit], %[bit], %[bit] \n\t" \
87  "sub.d %[c_low], %[c_low], %[tmp0] \n\t" \
88  \
89  "1: \n\t" \
90  /* tmp1: *state */ \
91  "add.d %[tmp0], %[tables], %[bit] \n\t" \
92  "ld.bu %[tmp1], %[tmp0], %[mlps_off] \n\t" \
93  /* tmp2: lps_mask */ \
94  "add.d %[tmp0], %[tables], %[c_range] \n\t" \
95  "ld.bu %[tmp2], %[tmp0], %[norm_off] \n\t" \
96  \
97  "andi %[bit], %[bit], 0x01 \n\t" \
98  "st.b %[tmp1], %[state], 0x0 \n\t" \
99  "sll.d %[c_range], %[c_range], %[tmp2] \n\t" \
100  "sll.d %[c_low], %[c_low], %[tmp2] \n\t" \
101  \
102  "and %[tmp1], %[c_low], %[cabac_mask] \n\t" \
103  "bnez %[tmp1], 1f \n\t" \
104  "ld.hu %[tmp1], %[c_bytestream], 0x0 \n\t" \
105  "ctz.d %[tmp0], %[c_low] \n\t" \
106  "addi.d %[tmp2], %[tmp0], -16 \n\t" \
107  "revb.2h %[tmp0], %[tmp1] \n\t" \
108  "slli.d %[tmp0], %[tmp0], 0x01 \n\t" \
109  "sub.d %[tmp0], %[tmp0], %[cabac_mask] \n\t" \
110  "sll.d %[tmp0], %[tmp0], %[tmp2] \n\t" \
111  \
112  "add.d %[c_low], %[c_low], %[tmp0] \n\t" \
113  \
114  "slt %[tmp0], %[c_bytestream], %[c_bytestream_end] \n\t" \
115  "add.d %[c_bytestream], %[c_bytestream], %[tmp0] \n\t" \
116  "add.d %[c_bytestream], %[c_bytestream], %[tmp0] \n\t" \
117  "1: \n\t" \
118 
119 #define get_cabac_inline get_cabac_inline_loongarch
120 static av_always_inline
121 int get_cabac_inline_loongarch(CABACContext *c, uint8_t * const state)
122 {
123  int64_t tmp0, tmp1, tmp2, bit;
124 
125  __asm__ volatile (
126 #if UNCHECKED_BITSTREAM_READER
127  GET_CABAC_LOONGARCH_UNCBSR
128 #else
129  GET_CABAC_LOONGARCH
130 #endif
131  : [bit]"=&r"(bit), [tmp0]"=&r"(tmp0), [tmp1]"=&r"(tmp1), [tmp2]"=&r"(tmp2),
132  [c_range]"+&r"(c->range), [c_low]"+&r"(c->low),
133  [c_bytestream]"+&r"(c->bytestream)
134  : [state]"r"(state), [tables]"r"(ff_h264_cabac_tables),
135 #if !UNCHECKED_BITSTREAM_READER
136  [c_bytestream_end]"r"(c->bytestream_end),
137 #endif
138  [lps_off]"i"(H264_LPS_RANGE_OFFSET),
139  [mlps_off]"i"(H264_MLPS_STATE_OFFSET + 128),
140  [norm_off]"i"(H264_NORM_SHIFT_OFFSET),
141  [cabac_mask]"r"(CABAC_MASK)
142  : "memory"
143  );
144 
145  return bit;
146 }
147 
148 #define get_cabac_bypass get_cabac_bypass_loongarch
149 static av_always_inline int get_cabac_bypass_loongarch(CABACContext *c)
150 {
151  int64_t tmp0, tmp1, tmp2;
152  int res = 0;
153  __asm__ volatile(
154  "slli.d %[c_low], %[c_low], 0x01 \n\t"
155  "and %[tmp0], %[c_low], %[cabac_mask] \n\t"
156  "bnez %[tmp0], 1f \n\t"
157  "ld.hu %[tmp1], %[c_bytestream], 0x0 \n\t"
158 #if UNCHECKED_BITSTREAM_READER
159  "addi.d %[c_bytestream], %[c_bytestream], 0x02 \n\t"
160 #else
161  "slt %[tmp0], %[c_bytestream], %[c_bytestream_end] \n\t"
162  "add.d %[c_bytestream], %[c_bytestream], %[tmp0] \n\t"
163  "add.d %[c_bytestream], %[c_bytestream], %[tmp0] \n\t"
164 #endif
165  "revb.2h %[tmp1], %[tmp1] \n\t"
166  "slli.d %[tmp1], %[tmp1], 0x01 \n\t"
167  "sub.d %[tmp1], %[tmp1], %[cabac_mask] \n\t"
168  "add.d %[c_low], %[c_low], %[tmp1] \n\t"
169  "1: \n\t"
170  "slli.d %[tmp1], %[c_range], 0x11 \n\t"
171  "slt %[tmp0], %[c_low], %[tmp1] \n\t"
172  "sub.d %[tmp1], %[c_low], %[tmp1] \n\t"
173  "masknez %[tmp2], %[one], %[tmp0] \n\t"
174  "maskeqz %[res], %[res], %[tmp0] \n\t"
175  "or %[res], %[res], %[tmp2] \n\t"
176  "masknez %[tmp2], %[tmp1], %[tmp0] \n\t"
177  "maskeqz %[c_low], %[c_low], %[tmp0] \n\t"
178  "or %[c_low], %[c_low], %[tmp2] \n\t"
179  : [tmp0]"=&r"(tmp0), [tmp1]"=&r"(tmp1), [tmp2]"=&r"(tmp2),
180  [c_range]"+&r"(c->range), [c_low]"+&r"(c->low),
181  [c_bytestream]"+&r"(c->bytestream), [res]"+&r"(res)
182  : [cabac_mask]"r"(CABAC_MASK),
183 #if !UNCHECKED_BITSTREAM_READER
184  [c_bytestream_end]"r"(c->bytestream_end),
185 #endif
186  [one]"r"(0x01)
187  : "memory"
188  );
189  return res;
190 }
191 
192 #define get_cabac_bypass_sign get_cabac_bypass_sign_loongarch
193 static av_always_inline
194 int get_cabac_bypass_sign_loongarch(CABACContext *c, int val)
195 {
196  int64_t tmp0, tmp1;
197  int res = val;
198  __asm__ volatile(
199  "slli.d %[c_low], %[c_low], 0x01 \n\t"
200  "and %[tmp0], %[c_low], %[cabac_mask] \n\t"
201  "bnez %[tmp0], 1f \n\t"
202  "ld.hu %[tmp1], %[c_bytestream], 0x0 \n\t"
203 #if UNCHECKED_BITSTREAM_READER
204  "addi.d %[c_bytestream], %[c_bytestream], 0x02 \n\t"
205 #else
206  "slt %[tmp0], %[c_bytestream], %[c_bytestream_end] \n\t"
207  "add.d %[c_bytestream], %[c_bytestream], %[tmp0] \n\t"
208  "add.d %[c_bytestream], %[c_bytestream], %[tmp0] \n\t"
209 #endif
210  "revb.2h %[tmp1], %[tmp1] \n\t"
211  "slli.d %[tmp1], %[tmp1], 0x01 \n\t"
212  "sub.d %[tmp1], %[tmp1], %[cabac_mask] \n\t"
213  "add.d %[c_low], %[c_low], %[tmp1] \n\t"
214  "1: \n\t"
215  "slli.d %[tmp1], %[c_range], 0x11 \n\t"
216  "slt %[tmp0], %[c_low], %[tmp1] \n\t"
217  "sub.d %[tmp1], %[c_low], %[tmp1] \n\t"
218  "masknez %[tmp1], %[tmp1], %[tmp0] \n\t"
219  "maskeqz %[c_low], %[c_low], %[tmp0] \n\t"
220  "or %[c_low], %[c_low], %[tmp1] \n\t"
221  "sub.d %[tmp1], %[zero], %[res] \n\t"
222  "maskeqz %[tmp1], %[tmp1], %[tmp0] \n\t"
223  "masknez %[res], %[res], %[tmp0] \n\t"
224  "or %[res], %[res], %[tmp1] \n\t"
225  : [tmp0]"=&r"(tmp0), [tmp1]"=&r"(tmp1), [res]"+&r"(res),
226  [c_range]"+&r"(c->range), [c_low]"+&r"(c->low),
227  [c_bytestream]"+&r"(c->bytestream)
228  : [cabac_mask]"r"(CABAC_MASK),
229 #if !UNCHECKED_BITSTREAM_READER
230  [c_bytestream_end]"r"(c->bytestream_end),
231 #endif
232  [zero]"r"(0x0)
233  : "memory"
234  );
235 
236  return res;
237 }
238 #endif /* AVCODEC_LOONGARCH_CABAC_H */
GET_CABAC_LOONGARCH_UNCBSR
#define GET_CABAC_LOONGARCH_UNCBSR
Definition: cabac.h:31
cabac.h
get_cabac_inline_loongarch
static av_always_inline int get_cabac_inline_loongarch(CABACContext *c, uint8_t *const state)
Definition: cabac.h:121
bit
#define bit(string, value)
Definition: cbs_mpeg2.c:58
tables
Writing a table generator This documentation is preliminary Parts of the API are not good and should be changed Basic concepts A table generator consists of two *_tablegen c and *_tablegen h The h file will provide the variable declarations and initialization code for the tables
Definition: tablegen.txt:10
val
static double val(void *priv, double ch)
Definition: aeval.c:77
ff_h264_cabac_tables
const uint8_t ff_h264_cabac_tables[512+4 *2 *64+4 *64+63]
CABAC_MASK
#define CABAC_MASK
Definition: cabac.h:39
GET_CABAC_LOONGARCH
#define GET_CABAC_LOONGARCH
Definition: cabac.h:73
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
state
static struct @327 state
H264_LPS_RANGE_OFFSET
#define H264_LPS_RANGE_OFFSET
Definition: cabac.h:34
av_always_inline
#define av_always_inline
Definition: attributes.h:49
get_cabac_bypass_loongarch
static av_always_inline int get_cabac_bypass_loongarch(CABACContext *c)
Definition: cabac.h:149
H264_NORM_SHIFT_OFFSET
#define H264_NORM_SHIFT_OFFSET
Definition: cabac.h:33
__asm__
__asm__(".macro parse_r var r\n\t" "\\var = -1\n\t" _IFC_REG(0) _IFC_REG(1) _IFC_REG(2) _IFC_REG(3) _IFC_REG(4) _IFC_REG(5) _IFC_REG(6) _IFC_REG(7) _IFC_REG(8) _IFC_REG(9) _IFC_REG(10) _IFC_REG(11) _IFC_REG(12) _IFC_REG(13) _IFC_REG(14) _IFC_REG(15) _IFC_REG(16) _IFC_REG(17) _IFC_REG(18) _IFC_REG(19) _IFC_REG(20) _IFC_REG(21) _IFC_REG(22) _IFC_REG(23) _IFC_REG(24) _IFC_REG(25) _IFC_REG(26) _IFC_REG(27) _IFC_REG(28) _IFC_REG(29) _IFC_REG(30) _IFC_REG(31) ".iflt \\var\n\t" ".error \"Unable to parse register name \\r\"\n\t" ".endif\n\t" ".endm")
get_cabac_bypass_sign_loongarch
static av_always_inline int get_cabac_bypass_sign_loongarch(CABACContext *c, int val)
Definition: cabac.h:194
UNCHECKED_BITSTREAM_READER
#define UNCHECKED_BITSTREAM_READER
Definition: cabac_functions.h:39
zero
#define zero
Definition: regdef.h:64
H264_MLPS_STATE_OFFSET
#define H264_MLPS_STATE_OFFSET
Definition: cabac.h:35
CABACContext
Definition: cabac.h:41
Generated on Wed Aug 24 2022 21:41:15 for FFmpeg by   doxygen 1.8.17