1 /*
2  * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
3  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * H.264 / AVC / MPEG-4 part10 codec.
25  * non-SIMD x86-specific optimizations for H.264
26  * @author Michael Niedermayer <michaelni@gmx.at>
27  */
28 
29 #include <stddef.h>
30 
31 #include "libavcodec/cabac.h"
32 #include "cabac.h"
33 
34 #if HAVE_INLINE_ASM
35 
36 #if ARCH_X86_64
37 #define REG64 "r"
38 #else
39 #define REG64 "m"
40 #endif
41 
42 //FIXME use some macros to avoid duplicating get_cabac (cannot be done yet
43 //as that would make optimization work hard)
44 #if HAVE_7REGS && !BROKEN_COMPILER
45 #define decode_significance decode_significance_x86
decode_significance_x86(CABACContext * c,int max_coeff,uint8_t * significant_coeff_ctx_base,int * index,x86_reg last_off)46 static int decode_significance_x86(CABACContext *c, int max_coeff,
47                                    uint8_t *significant_coeff_ctx_base,
48                                    int *index, x86_reg last_off){
49     void *end= significant_coeff_ctx_base + max_coeff - 1;
50     int minusstart= -(intptr_t)significant_coeff_ctx_base;
51     int minusindex= 4-(intptr_t)index;
52     int bit;
53     x86_reg coeff_count;
54 
55 #ifdef BROKEN_RELOCATIONS
56     void *tables;
57 
58     __asm__ volatile(
59         "lea   "MANGLE(ff_h264_cabac_tables)", %0      \n\t"
60         : "=&r"(tables)
61         : NAMED_CONSTRAINTS_ARRAY(ff_h264_cabac_tables)
62     );
63 #endif
64 
65     __asm__ volatile(
66         "3:                                     \n\t"
67 
68         BRANCHLESS_GET_CABAC("%4", "%q4", "(%1)", "%3", "%w3",
69                              "%5", "%q5", "%k0", "%b0",
70                              "%c11(%6)", "%c12(%6)",
71                              AV_STRINGIFY(H264_NORM_SHIFT_OFFSET),
72                              AV_STRINGIFY(H264_LPS_RANGE_OFFSET),
73                              AV_STRINGIFY(H264_MLPS_STATE_OFFSET),
74                              "%13")
75 
76         "test $1, %4                            \n\t"
77         " jz 4f                                 \n\t"
78         "add  %10, %1                           \n\t"
79 
80         BRANCHLESS_GET_CABAC("%4", "%q4", "(%1)", "%3", "%w3",
81                              "%5", "%q5", "%k0", "%b0",
82                              "%c11(%6)", "%c12(%6)",
83                              AV_STRINGIFY(H264_NORM_SHIFT_OFFSET),
84                              AV_STRINGIFY(H264_LPS_RANGE_OFFSET),
85                              AV_STRINGIFY(H264_MLPS_STATE_OFFSET),
86                              "%13")
87 
88         "sub  %10, %1                           \n\t"
89         "mov  %2, %0                            \n\t"
90         "movl %7, %%ecx                         \n\t"
91         "add  %1, %%"FF_REG_c"                  \n\t"
92         "movl %%ecx, (%0)                       \n\t"
93 
94         "test $1, %4                            \n\t"
95         " jnz 5f                                \n\t"
96 
97         "add"FF_OPSIZE"  $4, %2                 \n\t"
98 
99         "4:                                     \n\t"
100         "add  $1, %1                            \n\t"
101         "cmp  %8, %1                            \n\t"
102         " jb 3b                                 \n\t"
103         "mov  %2, %0                            \n\t"
104         "movl %7, %%ecx                         \n\t"
105         "add  %1, %%"FF_REG_c"                  \n\t"
106         "movl %%ecx, (%0)                       \n\t"
107         "5:                                     \n\t"
108         "add  %9, %k0                           \n\t"
109         "shr $2, %k0                            \n\t"
110         : "=&q"(coeff_count), "+r"(significant_coeff_ctx_base), "+m"(index),
111           "+&r"(c->low), "=&r"(bit), "+&r"(c->range)
112         : "r"(c), "m"(minusstart), "m"(end), "m"(minusindex), "m"(last_off),
113           "i"(offsetof(CABACContext, bytestream)),
114           "i"(offsetof(CABACContext, bytestream_end))
115           TABLES_ARG
116         : "%"FF_REG_c, "memory"
117     );
118     return coeff_count;
119 }
120 
121 #define decode_significance_8x8 decode_significance_8x8_x86
decode_significance_8x8_x86(CABACContext * c,uint8_t * significant_coeff_ctx_base,int * index,uint8_t * last_coeff_ctx_base,const uint8_t * sig_off)122 static int decode_significance_8x8_x86(CABACContext *c,
123                                        uint8_t *significant_coeff_ctx_base,
124                                        int *index, uint8_t *last_coeff_ctx_base, const uint8_t *sig_off){
125     int minusindex= 4-(intptr_t)index;
126     int bit;
127     x86_reg coeff_count;
128     x86_reg last=0;
129     x86_reg state;
130 
131 #ifdef BROKEN_RELOCATIONS
132     void *tables;
133 
134     __asm__ volatile(
135         "lea    "MANGLE(ff_h264_cabac_tables)", %0      \n\t"
136         : "=&r"(tables)
137         : NAMED_CONSTRAINTS_ARRAY(ff_h264_cabac_tables)
138     );
139 #endif
140 
141     __asm__ volatile(
142         "mov %1, %6                             \n\t"
143         "3:                                     \n\t"
144 
145         "mov %10, %0                            \n\t"
146         "movzb (%0, %6), %6                     \n\t"
147         "add %9, %6                             \n\t"
148 
149         BRANCHLESS_GET_CABAC("%4", "%q4", "(%6)", "%3", "%w3",
150                              "%5", "%q5", "%k0", "%b0",
151                              "%c12(%7)", "%c13(%7)",
152                              AV_STRINGIFY(H264_NORM_SHIFT_OFFSET),
153                              AV_STRINGIFY(H264_LPS_RANGE_OFFSET),
154                              AV_STRINGIFY(H264_MLPS_STATE_OFFSET),
155                              "%15")
156 
157         "mov %1, %6                             \n\t"
158         "test $1, %4                            \n\t"
159         " jz 4f                                 \n\t"
160 
161 #ifdef BROKEN_RELOCATIONS
162         "movzb %c14(%15, %q6), %6\n\t"
163 #else
164         "movzb "MANGLE(ff_h264_cabac_tables)"+%c14(%6), %6\n\t"
165 #endif
166         "add %11, %6                            \n\t"
167 
168         BRANCHLESS_GET_CABAC("%4", "%q4", "(%6)", "%3", "%w3",
169                              "%5", "%q5", "%k0", "%b0",
170                              "%c12(%7)", "%c13(%7)",
171                              AV_STRINGIFY(H264_NORM_SHIFT_OFFSET),
172                              AV_STRINGIFY(H264_LPS_RANGE_OFFSET),
173                              AV_STRINGIFY(H264_MLPS_STATE_OFFSET),
174                              "%15")
175 
176         "mov %2, %0                             \n\t"
177         "mov %1, %6                             \n\t"
178         "mov %k6, (%0)                          \n\t"
179 
180         "test $1, %4                            \n\t"
181         " jnz 5f                                \n\t"
182 
183         "add"FF_OPSIZE"  $4, %2                 \n\t"
184 
185         "4:                                     \n\t"
186         "add $1, %6                             \n\t"
187         "mov %6, %1                             \n\t"
188         "cmp $63, %6                            \n\t"
189         " jb 3b                                 \n\t"
190         "mov %2, %0                             \n\t"
191         "mov %k6, (%0)                          \n\t"
192         "5:                                     \n\t"
193         "addl %8, %k0                           \n\t"
194         "shr $2, %k0                            \n\t"
195         : "=&q"(coeff_count), "+"REG64(last), "+"REG64(index), "+&r"(c->low),
196           "=&r"(bit), "+&r"(c->range), "=&r"(state)
197         : "r"(c), "m"(minusindex), "m"(significant_coeff_ctx_base),
198           REG64(sig_off), REG64(last_coeff_ctx_base),
199           "i"(offsetof(CABACContext, bytestream)),
200           "i"(offsetof(CABACContext, bytestream_end)),
201           "i"(H264_LAST_COEFF_FLAG_OFFSET_8x8_OFFSET) TABLES_ARG
202         : "%"FF_REG_c, "memory"
203     );
204     return coeff_count;
205 }
206 #endif /* HAVE_7REGS && BROKEN_COMPILER */
207 
208 #endif /* HAVE_INLINE_ASM */
209