1/*
2 * Loongson  optimized cabac
3 *
4 * Copyright (c) 2021 Loongson Technology Corporation Limited
5 * Contributed by Hao Chen <chenhao@loongson.cn>
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#include "libavcodec/cabac.h"
25#include "cabac.h"
26
27#define decode_significance decode_significance_loongarch
28static int decode_significance_loongarch(CABACContext *c, int max_coeff,
29    uint8_t *significant_coeff_ctx_base, int *index, int64_t last_off)
30{
31    void *end = significant_coeff_ctx_base + max_coeff - 1;
32    int64_t minusstart = -(int64_t)significant_coeff_ctx_base;
33    int64_t minusindex = 4 - (int64_t)index;
34    int64_t bit, tmp0, tmp1, tmp2, one = 1;
35    uint8_t *state = significant_coeff_ctx_base;
36
37    __asm__ volatile(
38    "3:"
39#if UNCHECKED_BITSTREAM_READER
40    GET_CABAC_LOONGARCH_UNCBSR
41#else
42    GET_CABAC_LOONGARCH
43#endif
44    "blt     %[bit],          %[one],            4f               \n\t"
45    "add.d   %[state],        %[state],          %[last_off]      \n\t"
46#if UNCHECKED_BITSTREAM_READER
47    GET_CABAC_LOONGARCH_UNCBSR
48#else
49    GET_CABAC_LOONGARCH
50#endif
51    "sub.d   %[state],        %[state],          %[last_off]      \n\t"
52    "add.d   %[tmp0],         %[state],          %[minusstart]    \n\t"
53    "st.w    %[tmp0],         %[index],          0                \n\t"
54    "bge     %[bit],          %[one],            5f               \n\t"
55    "addi.d  %[index],        %[index],          4                \n\t"
56    "4:                                                           \n\t"
57    "addi.d  %[state],        %[state],          1                \n\t"
58    "blt     %[state],        %[end],            3b               \n\t"
59    "add.d   %[tmp0],         %[state],          %[minusstart]    \n\t"
60    "st.w    %[tmp0],         %[index],          0                \n\t"
61    "5:                                                           \n\t"
62    "add.d   %[tmp0],         %[index],          %[minusindex]    \n\t"
63    "srli.d  %[tmp0],         %[tmp0],           2                \n\t"
64    : [bit]"=&r"(bit), [tmp0]"=&r"(tmp0), [tmp1]"=&r"(tmp1), [tmp2]"=&r"(tmp2),
65      [c_range]"+&r"(c->range), [c_low]"+&r"(c->low), [state]"+&r"(state),
66      [c_bytestream]"+&r"(c->bytestream), [index]"+&r"(index)
67    : [tables]"r"(ff_h264_cabac_tables), [end]"r"(end), [one]"r"(one),
68      [minusstart]"r"(minusstart), [minusindex]"r"(minusindex),
69      [last_off]"r"(last_off),
70#if !UNCHECKED_BITSTREAM_READER
71      [c_bytestream_end]"r"(c->bytestream_end),
72#endif
73      [lps_off]"i"(H264_LPS_RANGE_OFFSET),
74      [mlps_off]"i"(H264_MLPS_STATE_OFFSET + 128),
75      [norm_off]"i"(H264_NORM_SHIFT_OFFSET),
76      [cabac_mask]"r"(CABAC_MASK)
77    : "memory"
78    );
79
80    return (int)tmp0;
81}
82
83#define decode_significance_8x8 decode_significance_8x8_loongarch
84static int decode_significance_8x8_loongarch(
85    CABACContext *c, uint8_t *significant_coeff_ctx_base,
86    int *index, uint8_t *last_coeff_ctx_base, const uint8_t *sig_off)
87{
88    int64_t minusindex = 4 - (int64_t)index;
89    int64_t bit, tmp0, tmp1, tmp2, one = 1, end =  63, last = 0;
90    uint8_t *state = 0;
91    int64_t flag_offset = H264_LAST_COEFF_FLAG_OFFSET_8x8_OFFSET;
92
93    __asm__ volatile(
94    "3:                                                              \n\t"
95    "ldx.bu   %[tmp0],     %[sig_off],       %[last]                 \n\t"
96    "add.d    %[state],    %[tmp0], %[significant_coeff_ctx_base]    \n\t"
97#if UNCHECKED_BITSTREAM_READER
98    GET_CABAC_LOONGARCH_UNCBSR
99#else
100    GET_CABAC_LOONGARCH
101#endif
102    "blt      %[bit],      %[one],           4f                      \n\t"
103    "add.d    %[tmp0],     %[tables],        %[flag_offset]          \n\t"
104    "ldx.bu   %[tmp1],     %[tmp0],          %[last]                 \n\t"
105    "add.d    %[state],    %[tmp1],    %[last_coeff_ctx_base]        \n\t"
106#if UNCHECKED_BITSTREAM_READER
107    GET_CABAC_LOONGARCH_UNCBSR
108#else
109    GET_CABAC_LOONGARCH
110#endif
111    "st.w    %[last],      %[index],         0                       \n\t"
112    "bge     %[bit],       %[one],           5f                      \n\t"
113    "addi.d  %[index],     %[index],         4                       \n\t"
114    "4:                                                              \n\t"
115    "addi.d  %[last],      %[last],          1                       \n\t"
116    "blt     %[last],      %[end],           3b                      \n\t"
117    "st.w    %[last],      %[index],         0                       \n\t"
118    "5:                                                              \n\t"
119    "add.d   %[tmp0],      %[index],         %[minusindex]           \n\t"
120    "srli.d  %[tmp0],      %[tmp0],          2                       \n\t"
121    : [bit]"=&r"(bit), [tmp0]"=&r"(tmp0), [tmp1]"=&r"(tmp1),
122      [tmp2]"=&r"(tmp2), [c_range]"+&r"(c->range),
123      [c_low]"+&r"(c->low), [state]"+&r"(state), [last]"+&r"(last),
124      [c_bytestream]"+&r"(c->bytestream), [index]"+&r"(index)
125    : [tables]"r"(ff_h264_cabac_tables), [end]"r"(end),
126      [one]"r"(one), [minusindex]"r"(minusindex),
127      [last_coeff_ctx_base]"r"(last_coeff_ctx_base),
128      [flag_offset]"r"(flag_offset),
129#if !UNCHECKED_BITSTREAM_READER
130      [c_bytestream_end]"r"(c->bytestream_end),
131#endif
132      [lps_off]"i"(H264_LPS_RANGE_OFFSET), [sig_off]"r"(sig_off),
133      [mlps_off]"i"(H264_MLPS_STATE_OFFSET + 128),
134      [norm_off]"i"(H264_NORM_SHIFT_OFFSET),
135      [cabac_mask]"r"(CABAC_MASK),
136      [significant_coeff_ctx_base]"r"(significant_coeff_ctx_base)
137    );
138
139    return (int)tmp0;
140}
141