1 ; 2 ; Copyright (c) 2010 The WebM project authors. All Rights Reserved. 3 ; 4 ; Use of this source code is governed by a BSD-style license 5 ; that can be found in the LICENSE file in the root of the source 6 ; tree. An additional intellectual property rights grant can be found 7 ; in the file PATENTS. All contributing project authors may 8 ; be found in the AUTHORS file in the root of the source tree. 9 ; 10 11 12 EXPORT |vp8cx_pack_tokens_armv5| 13 IMPORT |vp8_validate_buffer_arm| 14 15 INCLUDE vp8_asm_enc_offsets.asm 16 17 ARM 18 REQUIRE8 19 PRESERVE8 20 21 AREA |.text|, CODE, READONLY 22 23 24 ; macro for validating write buffer position 25 ; needs vp8_writer in r0 26 ; start shall not be in r1 27 MACRO 28 VALIDATE_POS $start, $pos 29 push {r0-r3, r12, lr} ; rest of regs are preserved by subroutine call 30 ldr r2, [r0, #vp8_writer_buffer_end] 31 ldr r3, [r0, #vp8_writer_error] 32 mov r1, $pos 33 mov r0, $start 34 bl vp8_validate_buffer_arm 35 pop {r0-r3, r12, lr} 36 MEND 37 38 39 ; r0 vp8_writer *w 40 ; r1 const TOKENEXTRA *p 41 ; r2 int xcount 42 ; r3 vp8_coef_encodings 43 ; s0 vp8_extra_bits 44 ; s1 vp8_coef_tree 45 |vp8cx_pack_tokens_armv5| PROC 46 push {r4-r12, lr} 47 sub sp, sp, #16 48 49 ; Add size of xcount * sizeof (TOKENEXTRA) to get stop 50 ; sizeof (TOKENEXTRA) is 8 51 add r2, r1, r2, lsl #3 ; stop = p + xcount*sizeof(TOKENEXTRA) 52 str r2, [sp, #0] 53 str r3, [sp, #8] ; save vp8_coef_encodings 54 ldr r2, [r0, #vp8_writer_lowvalue] 55 ldr r5, [r0, #vp8_writer_range] 56 ldr r3, [r0, #vp8_writer_count] 57 b check_p_lt_stop 58 59 while_p_lt_stop 60 ldrb r6, [r1, #tokenextra_token] ; t 61 ldr r4, [sp, #8] ; vp8_coef_encodings 62 mov lr, #0 63 add r4, r4, r6, lsl #3 ; a = vp8_coef_encodings + t 64 ldr r9, [r1, #tokenextra_context_tree] ; pp 65 66 ldrb r7, [r1, #tokenextra_skip_eob_node] 67 68 ldr r6, [r4, #vp8_token_value] ; v 69 ldr r8, [r4, #vp8_token_len] ; n 70 71 ; vp8 specific skip_eob_node 72 cmp r7, #0 73 movne lr, #2 ; i = 2 74 subne r8, r8, #1 ; --n 75 76 rsb r4, r8, #32 ; 32-n 77 ldr r10, [sp, #60] ; vp8_coef_tree 78 79 ; v is kept in r12 during the token pack loop 80 lsl r12, r6, r4 ; r12 = v << 32 - n 81 82 ; loop start 83 token_loop 84 ldrb r4, [r9, lr, asr #1] ; pp [i>>1] 85 sub r7, r5, #1 ; range-1 86 87 ; Decisions are made based on the bit value shifted 88 ; off of v, so set a flag here based on this. 89 ; This value is refered to as "bb" 90 lsls r12, r12, #1 ; bb = v >> n 91 mul r6, r4, r7 ; ((range-1) * pp[i>>1])) 92 93 ; bb can only be 0 or 1. So only execute this statement 94 ; if bb == 1, otherwise it will act like i + 0 95 addcs lr, lr, #1 ; i + bb 96 97 mov r7, #1 98 ldrsb lr, [r10, lr] ; i = vp8_coef_tree[i+bb] 99 add r4, r7, r6, lsr #8 ; 1 + (((range-1) * pp[i>>1]) >> 8) 100 101 addcs r2, r2, r4 ; if (bb) lowvalue += split 102 subcs r4, r5, r4 ; if (bb) range = range-split 103 104 ; Counting the leading zeros is used to normalize range. 105 clz r6, r4 106 sub r6, r6, #24 ; shift 107 108 ; Flag is set on the sum of count. This flag is used later 109 ; to determine if count >= 0 110 adds r3, r3, r6 ; count += shift 111 lsl r5, r4, r6 ; range <<= shift 112 bmi token_count_lt_zero ; if(count >= 0) 113 114 sub r6, r6, r3 ; offset = shift - count 115 sub r4, r6, #1 ; offset-1 116 lsls r4, r2, r4 ; if((lowvalue<<(offset-1)) & 0x80000000 ) 117 bpl token_high_bit_not_set 118 119 ldr r4, [r0, #vp8_writer_pos] ; x 120 sub r4, r4, #1 ; x = w->pos-1 121 b token_zero_while_start 122 token_zero_while_loop 123 mov r10, #0 124 strb r10, [r7, r4] ; w->buffer[x] =(unsigned char)0 125 sub r4, r4, #1 ; x-- 126 token_zero_while_start 127 cmp r4, #0 128 ldrge r7, [r0, #vp8_writer_buffer] 129 ldrb r11, [r7, r4] 130 cmpge r11, #0xff 131 beq token_zero_while_loop 132 133 ldr r7, [r0, #vp8_writer_buffer] 134 ldrb r10, [r7, r4] ; w->buffer[x] 135 add r10, r10, #1 136 strb r10, [r7, r4] ; w->buffer[x] + 1 137 token_high_bit_not_set 138 rsb r4, r6, #24 ; 24-offset 139 ldr r10, [r0, #vp8_writer_buffer] 140 lsr r7, r2, r4 ; lowvalue >> (24-offset) 141 ldr r4, [r0, #vp8_writer_pos] ; w->pos 142 lsl r2, r2, r6 ; lowvalue <<= offset 143 mov r6, r3 ; shift = count 144 add r11, r4, #1 ; w->pos++ 145 bic r2, r2, #0xff000000 ; lowvalue &= 0xffffff 146 str r11, [r0, #vp8_writer_pos] 147 sub r3, r3, #8 ; count -= 8 148 149 VALIDATE_POS r10, r11 ; validate_buffer at pos 150 151 strb r7, [r10, r4] ; w->buffer[w->pos++] 152 153 ; r10 is used earlier in the loop, but r10 is used as 154 ; temp variable here. So after r10 is used, reload 155 ; vp8_coef_tree_dcd into r10 156 ldr r10, [sp, #60] ; vp8_coef_tree 157 158 token_count_lt_zero 159 lsl r2, r2, r6 ; lowvalue <<= shift 160 161 subs r8, r8, #1 ; --n 162 bne token_loop 163 164 ldrb r6, [r1, #tokenextra_token] ; t 165 ldr r7, [sp, #56] ; vp8_extra_bits 166 ; Add t * sizeof (vp8_extra_bit_struct) to get the desired 167 ; element. Here vp8_extra_bit_struct == 16 168 add r12, r7, r6, lsl #4 ; b = vp8_extra_bits + t 169 170 ldr r4, [r12, #vp8_extra_bit_struct_base_val] 171 cmp r4, #0 172 beq skip_extra_bits 173 174 ; if( b->base_val) 175 ldr r8, [r12, #vp8_extra_bit_struct_len] ; L 176 ldrsh lr, [r1, #tokenextra_extra] ; e = p->Extra 177 cmp r8, #0 ; if( L) 178 beq no_extra_bits 179 180 ldr r9, [r12, #vp8_extra_bit_struct_prob] 181 asr r7, lr, #1 ; v=e>>1 182 183 ldr r10, [r12, #vp8_extra_bit_struct_tree] 184 str r10, [sp, #4] ; b->tree 185 186 rsb r4, r8, #32 187 lsl r12, r7, r4 188 189 mov lr, #0 ; i = 0 190 191 extra_bits_loop 192 ldrb r4, [r9, lr, asr #1] ; pp[i>>1] 193 sub r7, r5, #1 ; range-1 194 lsls r12, r12, #1 ; v >> n 195 mul r6, r4, r7 ; (range-1) * pp[i>>1] 196 addcs lr, lr, #1 ; i + bb 197 198 mov r7, #1 199 ldrsb lr, [r10, lr] ; i = b->tree[i+bb] 200 add r4, r7, r6, lsr #8 ; split = 1 + (((range-1) * pp[i>>1]) >> 8) 201 202 addcs r2, r2, r4 ; if (bb) lowvalue += split 203 subcs r4, r5, r4 ; if (bb) range = range-split 204 205 clz r6, r4 206 sub r6, r6, #24 207 208 adds r3, r3, r6 ; count += shift 209 lsl r5, r4, r6 ; range <<= shift 210 bmi extra_count_lt_zero ; if(count >= 0) 211 212 sub r6, r6, r3 ; offset= shift - count 213 sub r4, r6, #1 ; offset-1 214 lsls r4, r2, r4 ; if((lowvalue<<(offset-1)) & 0x80000000 ) 215 bpl extra_high_bit_not_set 216 217 ldr r4, [r0, #vp8_writer_pos] ; x 218 sub r4, r4, #1 ; x = w->pos - 1 219 b extra_zero_while_start 220 extra_zero_while_loop 221 mov r10, #0 222 strb r10, [r7, r4] ; w->buffer[x] =(unsigned char)0 223 sub r4, r4, #1 ; x-- 224 extra_zero_while_start 225 cmp r4, #0 226 ldrge r7, [r0, #vp8_writer_buffer] 227 ldrb r11, [r7, r4] 228 cmpge r11, #0xff 229 beq extra_zero_while_loop 230 231 ldr r7, [r0, #vp8_writer_buffer] 232 ldrb r10, [r7, r4] 233 add r10, r10, #1 234 strb r10, [r7, r4] 235 extra_high_bit_not_set 236 rsb r4, r6, #24 ; 24-offset 237 ldr r10, [r0, #vp8_writer_buffer] 238 lsr r7, r2, r4 ; lowvalue >> (24-offset) 239 ldr r4, [r0, #vp8_writer_pos] 240 lsl r2, r2, r6 ; lowvalue <<= offset 241 mov r6, r3 ; shift = count 242 add r11, r4, #1 ; w->pos++ 243 bic r2, r2, #0xff000000 ; lowvalue &= 0xffffff 244 str r11, [r0, #vp8_writer_pos] 245 sub r3, r3, #8 ; count -= 8 246 247 VALIDATE_POS r10, r11 ; validate_buffer at pos 248 249 strb r7, [r10, r4] ; w->buffer[w->pos++]=(lowvalue >> (24-offset)) 250 ldr r10, [sp, #4] ; b->tree 251 extra_count_lt_zero 252 lsl r2, r2, r6 253 254 subs r8, r8, #1 ; --n 255 bne extra_bits_loop ; while (n) 256 257 no_extra_bits 258 ldr lr, [r1, #4] ; e = p->Extra 259 add r4, r5, #1 ; range + 1 260 tst lr, #1 261 lsr r4, r4, #1 ; split = (range + 1) >> 1 262 addne r2, r2, r4 ; lowvalue += split 263 subne r4, r5, r4 ; range = range-split 264 tst r2, #0x80000000 ; lowvalue & 0x80000000 265 lsl r5, r4, #1 ; range <<= 1 266 beq end_high_bit_not_set 267 268 ldr r4, [r0, #vp8_writer_pos] 269 mov r7, #0 270 sub r4, r4, #1 271 b end_zero_while_start 272 end_zero_while_loop 273 strb r7, [r6, r4] 274 sub r4, r4, #1 ; x-- 275 end_zero_while_start 276 cmp r4, #0 277 ldrge r6, [r0, #vp8_writer_buffer] 278 ldrb r12, [r6, r4] 279 cmpge r12, #0xff 280 beq end_zero_while_loop 281 282 ldr r6, [r0, #vp8_writer_buffer] 283 ldrb r7, [r6, r4] 284 add r7, r7, #1 285 strb r7, [r6, r4] 286 end_high_bit_not_set 287 adds r3, r3, #1 ; ++count 288 lsl r2, r2, #1 ; lowvalue <<= 1 289 bne end_count_zero 290 291 ldr r4, [r0, #vp8_writer_pos] 292 mvn r3, #7 293 ldr r7, [r0, #vp8_writer_buffer] 294 lsr r6, r2, #24 ; lowvalue >> 24 295 add r12, r4, #1 ; w->pos++ 296 bic r2, r2, #0xff000000 ; lowvalue &= 0xffffff 297 str r12, [r0, #vp8_writer_pos] 298 299 VALIDATE_POS r7, r12 ; validate_buffer at pos 300 301 strb r6, [r7, r4] 302 end_count_zero 303 skip_extra_bits 304 add r1, r1, #TOKENEXTRA_SZ ; ++p 305 check_p_lt_stop 306 ldr r4, [sp, #0] ; stop 307 cmp r1, r4 ; while( p < stop) 308 bcc while_p_lt_stop 309 310 str r2, [r0, #vp8_writer_lowvalue] 311 str r5, [r0, #vp8_writer_range] 312 str r3, [r0, #vp8_writer_count] 313 add sp, sp, #16 314 pop {r4-r12, pc} 315 ENDP 316 317 END 318
