FFmpeg
cabac.h
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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 "libavutil/attributes.h"
29 #include "libavcodec/cabac.h"
30 #include "config.h"
31 
32 #define GET_CABAC_LOONGARCH_UNCBSR \
33  "ld.bu %[bit], %[state], 0x0 \n\t" \
34  "andi %[tmp0], %[c_range], 0xC0 \n\t" \
35  "slli.d %[tmp0], %[tmp0], 0x01 \n\t" \
36  "add.d %[tmp0], %[tmp0], %[tables] \n\t" \
37  "add.d %[tmp0], %[tmp0], %[bit] \n\t" \
38  /* tmp1: RangeLPS */ \
39  "ld.bu %[tmp1], %[tmp0], %[lps_off] \n\t" \
40  \
41  "sub.d %[c_range], %[c_range], %[tmp1] \n\t" \
42  "slli.d %[tmp0], %[c_range], 0x11 \n\t" \
43  "bge %[tmp0], %[c_low], 1f \n\t" \
44  "move %[c_range], %[tmp1] \n\t" \
45  "nor %[bit], %[bit], %[bit] \n\t" \
46  "sub.d %[c_low], %[c_low], %[tmp0] \n\t" \
47  \
48  "1: \n\t" \
49  /* tmp1: *state */ \
50  "add.d %[tmp0], %[tables], %[bit] \n\t" \
51  "ld.bu %[tmp1], %[tmp0], %[mlps_off] \n\t" \
52  /* tmp2: lps_mask */ \
53  "add.d %[tmp0], %[tables], %[c_range] \n\t" \
54  "ld.bu %[tmp2], %[tmp0], %[norm_off] \n\t" \
55  \
56  "andi %[bit], %[bit], 0x01 \n\t" \
57  "st.b %[tmp1], %[state], 0x0 \n\t" \
58  "sll.d %[c_range], %[c_range], %[tmp2] \n\t" \
59  "sll.d %[c_low], %[c_low], %[tmp2] \n\t" \
60  \
61  "and %[tmp1], %[c_low], %[cabac_mask] \n\t" \
62  "bnez %[tmp1], 1f \n\t" \
63  "ld.hu %[tmp1], %[c_bytestream], 0x0 \n\t" \
64  "ctz.d %[tmp0], %[c_low] \n\t" \
65  "addi.d %[tmp2], %[tmp0], -16 \n\t" \
66  "revb.2h %[tmp0], %[tmp1] \n\t" \
67  "slli.d %[tmp0], %[tmp0], 0x01 \n\t" \
68  "sub.d %[tmp0], %[tmp0], %[cabac_mask] \n\t" \
69  "sll.d %[tmp0], %[tmp0], %[tmp2] \n\t" \
70  "add.d %[c_low], %[c_low], %[tmp0] \n\t" \
71  "addi.d %[c_bytestream], %[c_bytestream], 0x02 \n\t" \
72  "1: \n\t" \
73 
74 #define GET_CABAC_LOONGARCH \
75  "ld.bu %[bit], %[state], 0x0 \n\t" \
76  "andi %[tmp0], %[c_range], 0xC0 \n\t" \
77  "slli.d %[tmp0], %[tmp0], 0x01 \n\t" \
78  "add.d %[tmp0], %[tmp0], %[tables] \n\t" \
79  "add.d %[tmp0], %[tmp0], %[bit] \n\t" \
80  /* tmp1: RangeLPS */ \
81  "ld.bu %[tmp1], %[tmp0], %[lps_off] \n\t" \
82  \
83  "sub.d %[c_range], %[c_range], %[tmp1] \n\t" \
84  "slli.d %[tmp0], %[c_range], 0x11 \n\t" \
85  "bge %[tmp0], %[c_low], 1f \n\t" \
86  "move %[c_range], %[tmp1] \n\t" \
87  "nor %[bit], %[bit], %[bit] \n\t" \
88  "sub.d %[c_low], %[c_low], %[tmp0] \n\t" \
89  \
90  "1: \n\t" \
91  /* tmp1: *state */ \
92  "add.d %[tmp0], %[tables], %[bit] \n\t" \
93  "ld.bu %[tmp1], %[tmp0], %[mlps_off] \n\t" \
94  /* tmp2: lps_mask */ \
95  "add.d %[tmp0], %[tables], %[c_range] \n\t" \
96  "ld.bu %[tmp2], %[tmp0], %[norm_off] \n\t" \
97  \
98  "andi %[bit], %[bit], 0x01 \n\t" \
99  "st.b %[tmp1], %[state], 0x0 \n\t" \
100  "sll.d %[c_range], %[c_range], %[tmp2] \n\t" \
101  "sll.d %[c_low], %[c_low], %[tmp2] \n\t" \
102  \
103  "and %[tmp1], %[c_low], %[cabac_mask] \n\t" \
104  "bnez %[tmp1], 1f \n\t" \
105  "ld.hu %[tmp1], %[c_bytestream], 0x0 \n\t" \
106  "ctz.d %[tmp0], %[c_low] \n\t" \
107  "addi.d %[tmp2], %[tmp0], -16 \n\t" \
108  "revb.2h %[tmp0], %[tmp1] \n\t" \
109  "slli.d %[tmp0], %[tmp0], 0x01 \n\t" \
110  "sub.d %[tmp0], %[tmp0], %[cabac_mask] \n\t" \
111  "sll.d %[tmp0], %[tmp0], %[tmp2] \n\t" \
112  \
113  "add.d %[c_low], %[c_low], %[tmp0] \n\t" \
114  \
115  "slt %[tmp0], %[c_bytestream], %[c_bytestream_end] \n\t" \
116  "add.d %[c_bytestream], %[c_bytestream], %[tmp0] \n\t" \
117  "add.d %[c_bytestream], %[c_bytestream], %[tmp0] \n\t" \
118  "1: \n\t" \
119 
120 #define get_cabac_inline get_cabac_inline_loongarch
121 static av_always_inline
123 {
124  int64_t tmp0, tmp1, tmp2, bit;
125 
126  __asm__ volatile (
127 #if UNCHECKED_BITSTREAM_READER
129 #else
131 #endif
132  : [bit]"=&r"(bit), [tmp0]"=&r"(tmp0), [tmp1]"=&r"(tmp1), [tmp2]"=&r"(tmp2),
133  [c_range]"+&r"(c->range), [c_low]"+&r"(c->low),
134  [c_bytestream]"+&r"(c->bytestream)
135  : [state]"r"(state), [tables]"r"(ff_h264_cabac_tables),
137  [c_bytestream_end]"r"(c->bytestream_end),
138 #endif
139  [lps_off]"i"(H264_LPS_RANGE_OFFSET),
140  [mlps_off]"i"(H264_MLPS_STATE_OFFSET + 128),
141  [norm_off]"i"(H264_NORM_SHIFT_OFFSET),
142  [cabac_mask]"r"(CABAC_MASK)
143  : "memory"
144  );
145 
146  return bit;
147 }
148 
149 #define get_cabac_bypass get_cabac_bypass_loongarch
151 {
152  int64_t tmp0, tmp1, tmp2;
153  int res = 0;
154  __asm__ volatile(
155  "slli.d %[c_low], %[c_low], 0x01 \n\t"
156  "and %[tmp0], %[c_low], %[cabac_mask] \n\t"
157  "bnez %[tmp0], 1f \n\t"
158  "ld.hu %[tmp1], %[c_bytestream], 0x0 \n\t"
159 #if UNCHECKED_BITSTREAM_READER
160  "addi.d %[c_bytestream], %[c_bytestream], 0x02 \n\t"
161 #else
162  "slt %[tmp0], %[c_bytestream], %[c_bytestream_end] \n\t"
163  "add.d %[c_bytestream], %[c_bytestream], %[tmp0] \n\t"
164  "add.d %[c_bytestream], %[c_bytestream], %[tmp0] \n\t"
165 #endif
166  "revb.2h %[tmp1], %[tmp1] \n\t"
167  "slli.d %[tmp1], %[tmp1], 0x01 \n\t"
168  "sub.d %[tmp1], %[tmp1], %[cabac_mask] \n\t"
169  "add.d %[c_low], %[c_low], %[tmp1] \n\t"
170  "1: \n\t"
171  "slli.d %[tmp1], %[c_range], 0x11 \n\t"
172  "slt %[tmp0], %[c_low], %[tmp1] \n\t"
173  "sub.d %[tmp1], %[c_low], %[tmp1] \n\t"
174  "masknez %[tmp2], %[one], %[tmp0] \n\t"
175  "maskeqz %[res], %[res], %[tmp0] \n\t"
176  "or %[res], %[res], %[tmp2] \n\t"
177  "masknez %[tmp2], %[tmp1], %[tmp0] \n\t"
178  "maskeqz %[c_low], %[c_low], %[tmp0] \n\t"
179  "or %[c_low], %[c_low], %[tmp2] \n\t"
180  : [tmp0]"=&r"(tmp0), [tmp1]"=&r"(tmp1), [tmp2]"=&r"(tmp2),
181  [c_range]"+&r"(c->range), [c_low]"+&r"(c->low),
182  [c_bytestream]"+&r"(c->bytestream), [res]"+&r"(res)
183  : [cabac_mask]"r"(CABAC_MASK),
184 #if !UNCHECKED_BITSTREAM_READER
185  [c_bytestream_end]"r"(c->bytestream_end),
186 #endif
187  [one]"r"(0x01)
188  : "memory"
189  );
190  return res;
191 }
192 
193 #define get_cabac_bypass_sign get_cabac_bypass_sign_loongarch
194 static av_always_inline
196 {
197  int64_t tmp0, tmp1;
198  int res = val;
199  __asm__ volatile(
200  "slli.d %[c_low], %[c_low], 0x01 \n\t"
201  "and %[tmp0], %[c_low], %[cabac_mask] \n\t"
202  "bnez %[tmp0], 1f \n\t"
203  "ld.hu %[tmp1], %[c_bytestream], 0x0 \n\t"
204 #if UNCHECKED_BITSTREAM_READER
205  "addi.d %[c_bytestream], %[c_bytestream], 0x02 \n\t"
206 #else
207  "slt %[tmp0], %[c_bytestream], %[c_bytestream_end] \n\t"
208  "add.d %[c_bytestream], %[c_bytestream], %[tmp0] \n\t"
209  "add.d %[c_bytestream], %[c_bytestream], %[tmp0] \n\t"
210 #endif
211  "revb.2h %[tmp1], %[tmp1] \n\t"
212  "slli.d %[tmp1], %[tmp1], 0x01 \n\t"
213  "sub.d %[tmp1], %[tmp1], %[cabac_mask] \n\t"
214  "add.d %[c_low], %[c_low], %[tmp1] \n\t"
215  "1: \n\t"
216  "slli.d %[tmp1], %[c_range], 0x11 \n\t"
217  "slt %[tmp0], %[c_low], %[tmp1] \n\t"
218  "sub.d %[tmp1], %[c_low], %[tmp1] \n\t"
219  "masknez %[tmp1], %[tmp1], %[tmp0] \n\t"
220  "maskeqz %[c_low], %[c_low], %[tmp0] \n\t"
221  "or %[c_low], %[c_low], %[tmp1] \n\t"
222  "sub.d %[tmp1], %[zero], %[res] \n\t"
223  "maskeqz %[tmp1], %[tmp1], %[tmp0] \n\t"
224  "masknez %[res], %[res], %[tmp0] \n\t"
225  "or %[res], %[res], %[tmp1] \n\t"
226  : [tmp0]"=&r"(tmp0), [tmp1]"=&r"(tmp1), [res]"+&r"(res),
227  [c_range]"+&r"(c->range), [c_low]"+&r"(c->low),
228  [c_bytestream]"+&r"(c->bytestream)
229  : [cabac_mask]"r"(CABAC_MASK),
231  [c_bytestream_end]"r"(c->bytestream_end),
232 #endif
233  [zero]"r"(0x0)
234  : "memory"
235  );
236 
237  return res;
238 }
239 #endif /* AVCODEC_LOONGARCH_CABAC_H */
GET_CABAC_LOONGARCH_UNCBSR
#define GET_CABAC_LOONGARCH_UNCBSR
Definition: cabac.h:32
cabac.h
get_cabac_inline_loongarch
static av_always_inline int get_cabac_inline_loongarch(CABACContext *c, uint8_t *const state)
Definition: cabac.h:122
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:74
state
static struct @336 state
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
H264_LPS_RANGE_OFFSET
#define H264_LPS_RANGE_OFFSET
Definition: cabac.h:34
attributes.h
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:150
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:195
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