Gloria Wang | 7913073 | 2010-02-08 14:41:04 -0800 | [diff] [blame] | 1 | @ Tremolo library |
Gloria Wang | 2da723a | 2010-03-18 15:56:16 -0700 | [diff] [blame] | 2 | @----------------------------------------------------------------------- |
| 3 | @ Copyright (C) 2002-2009, Xiph.org Foundation |
| 4 | @ Copyright (C) 2010, Robin Watts for Pinknoise Productions Ltd |
| 5 | @ All rights reserved. |
| 6 | |
| 7 | @ Redistribution and use in source and binary forms, with or without |
| 8 | @ modification, are permitted provided that the following conditions |
| 9 | @ are met: |
| 10 | |
| 11 | @ * Redistributions of source code must retain the above copyright |
| 12 | @ notice, this list of conditions and the following disclaimer. |
| 13 | @ * Redistributions in binary form must reproduce the above |
| 14 | @ copyright notice, this list of conditions and the following disclaimer |
| 15 | @ in the documentation and/or other materials provided with the |
| 16 | @ distribution. |
| 17 | @ * Neither the names of the Xiph.org Foundation nor Pinknoise |
| 18 | @ Productions Ltd nor the names of its contributors may be used to |
| 19 | @ endorse or promote products derived from this software without |
| 20 | @ specific prior written permission. |
| 21 | @ |
| 22 | @ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 23 | @ "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 24 | @ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 25 | @ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 26 | @ OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 27 | @ SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 28 | @ LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 29 | @ DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 30 | @ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 31 | @ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 32 | @ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 33 | @ ---------------------------------------------------------------------- |
Gloria Wang | 7913073 | 2010-02-08 14:41:04 -0800 | [diff] [blame] | 34 | |
| 35 | .text |
| 36 | |
| 37 | .global oggpack_look |
| 38 | .global oggpack_adv |
| 39 | .global oggpack_readinit |
| 40 | .global oggpack_read |
| 41 | |
| 42 | oggpack_look: |
| 43 | @ r0 = oggpack_buffer *b |
| 44 | @ r1 = int bits |
| 45 | STMFD r13!,{r10,r11,r14} |
| 46 | LDMIA r0,{r2,r3,r12} |
| 47 | @ r2 = bitsLeftInSegment |
| 48 | @ r3 = ptr |
| 49 | @ r12= bitsLeftInWord |
| 50 | SUBS r2,r2,r1 @ bitsLeftinSegment -= bits |
| 51 | BLT look_slow @ Not enough bits in this segment for |
| 52 | @ this request. Do it slowly. |
| 53 | LDR r10,[r3] @ r10= ptr[0] |
| 54 | RSB r14,r12,#32 @ r14= 32-bitsLeftInWord |
| 55 | SUBS r12,r12,r1 @ r12= bitsLeftInWord -= bits |
| 56 | LDRLT r11,[r3,#4]! @ r11= ptr[1] |
| 57 | MOV r10,r10,LSR r14 @ r10= ptr[0]>>(32-bitsLeftInWord) |
| 58 | ADDLE r12,r12,#32 @ r12= bitsLeftInWord += 32 |
| 59 | RSB r14,r14,#32 @ r14= 32-bitsLeftInWord |
| 60 | ORRLT r10,r10,r11,LSL r14 @ r10= Next 32 bits. |
| 61 | MOV r14,#1 |
| 62 | RSB r14,r14,r14,LSL r1 |
| 63 | AND r0,r10,r14 |
| 64 | LDMFD r13!,{r10,r11,PC} |
| 65 | |
| 66 | look_slow: |
| 67 | STMFD r13!,{r5,r6} |
| 68 | ADDS r10,r2,r1 @ r10= bitsLeftInSegment + bits (i.e. |
| 69 | @ the initial value of bitsLeftInSeg) |
| 70 | @ r10 = bitsLeftInSegment (initial) |
| 71 | @ r12 = bitsLeftInWord |
| 72 | RSB r14,r12,#32 @ r14= 32-bitsLeftInWord |
| 73 | MOV r5,r10 @ r5 = bitsLeftInSegment (initial) |
| 74 | BLT look_overrun |
| 75 | BEQ look_next_segment @ r10= r12 = 0, if we branch |
| 76 | CMP r12,r10 @ If bitsLeftInWord < bitsLeftInSeg |
| 77 | @ there must be more in the next word |
| 78 | LDR r10,[r3],#4 @ r10= ptr[0] |
| 79 | LDRLT r6,[r3] @ r6 = ptr[1] |
| 80 | MOV r11,#1 |
| 81 | MOV r10,r10,LSR r14 @ r10= first bitsLeftInWord bits |
| 82 | ORRLT r10,r10,r6,LSL r12 @ r10= first bitsLeftInSeg bits+crap |
| 83 | RSB r11,r11,r11,LSL r5 @ r11= mask |
| 84 | AND r10,r10,r11 @ r10= first r5 bits |
| 85 | @ Load the next segments data |
| 86 | look_next_segment: |
| 87 | @ At this point, r10 contains the first r5 bits of the result |
| 88 | LDR r11,[r0,#12] @ r11= head = b->head |
| 89 | @ Stall |
| 90 | @ Stall |
| 91 | look_next_segment_2: |
| 92 | LDR r11,[r11,#12] @ r11= head = head->next |
| 93 | @ Stall |
| 94 | @ Stall |
| 95 | CMP r11,#0 |
| 96 | BEQ look_out_of_data |
| 97 | LDMIA r11,{r6,r12,r14} @ r6 = buffer |
| 98 | @ r12= begin |
| 99 | @ r14= length |
| 100 | LDR r6,[r6] @ r6 = buffer->data |
| 101 | CMP r14,#0 |
| 102 | BEQ look_next_segment_2 |
| 103 | ADD r6,r6,r12 @ r6 = buffer->data+begin |
| 104 | look_slow_loop: |
| 105 | LDRB r12,[r6],#1 @ r12= *buffer |
| 106 | SUBS r14,r14,#1 @ r14= length |
| 107 | @ Stall |
| 108 | ORR r10,r10,r12,LSL r5 @ r10= first r5+8 bits |
| 109 | ADD r5,r5,#8 |
| 110 | BLE look_really_slow |
| 111 | CMP r5,r1 |
| 112 | BLT look_slow_loop |
| 113 | MOV r14,#1 |
| 114 | RSB r14,r14,r14,LSL r1 |
| 115 | AND r0,r10,r14 |
| 116 | LDMFD r13!,{r5,r6,r10,r11,PC} |
| 117 | |
| 118 | |
| 119 | look_really_slow: |
| 120 | CMP r5,r1 |
| 121 | BLT look_next_segment_2 |
| 122 | MOV r14,#1 |
| 123 | RSB r14,r14,r14,LSL r1 |
| 124 | AND r0,r10,r14 |
| 125 | LDMFD r13!,{r5,r6,r10,r11,PC} |
| 126 | |
| 127 | look_out_of_data: |
| 128 | @MVN r0,#0 ; return -1 |
| 129 | MOV r0,#0 |
| 130 | LDMFD r13!,{r5,r6,r10,r11,PC} |
| 131 | |
| 132 | look_overrun: |
| 133 | @ We had overrun when we started, so we need to skip -r10 bits. |
| 134 | LDR r11,[r0,#12] @ r11 = head = b->head |
| 135 | @ stall |
| 136 | @ stall |
| 137 | look_overrun_next_segment: |
| 138 | LDR r11,[r11,#12] @ r11 = head->next |
| 139 | @ stall |
| 140 | @ stall |
| 141 | CMP r11,#0 |
| 142 | BEQ look_out_of_data |
| 143 | LDMIA r11,{r6,r7,r14} @ r6 = buffer |
| 144 | @ r7 = begin |
| 145 | @ r14= length |
| 146 | LDR r6,[r6] @ r6 = buffer->data |
| 147 | @ stall |
| 148 | @ stall |
| 149 | ADD r6,r6,r7 @ r6 = buffer->data+begin |
| 150 | MOV r14,r14,LSL #3 @ r14= length in bits |
| 151 | ADDS r14,r14,r10 @ r14= length in bits-bits to skip |
| 152 | MOVLE r10,r14 |
| 153 | BLE look_overrun_next_segment |
| 154 | RSB r10,r10,#0 @ r10= bits to skip |
| 155 | ADD r6,r10,r10,LSR #3 @ r6 = pointer to data |
| 156 | MOV r10,#0 |
| 157 | B look_slow_loop |
| 158 | |
| 159 | oggpack_adv: |
| 160 | @ r0 = oggpack_buffer *b |
| 161 | @ r1 = bits |
| 162 | LDMIA r0,{r2,r3,r12} |
| 163 | @ r2 = bitsLeftInSegment |
| 164 | @ r3 = ptr |
| 165 | @ r12= bitsLeftInWord |
| 166 | SUBS r2,r2,r1 @ Does this run us out of bits in the |
| 167 | BLE adv_slow @ segment? If so, do it slowly |
| 168 | SUBS r12,r12,r1 |
| 169 | ADDLE r12,r12,#32 |
| 170 | ADDLE r3,r3,#4 |
| 171 | STMIA r0,{r2,r3,r12} |
Andreas Huber | 9a68875 | 2010-06-23 10:01:39 -0700 | [diff] [blame] | 172 | BX LR |
Gloria Wang | 7913073 | 2010-02-08 14:41:04 -0800 | [diff] [blame] | 173 | adv_slow: |
| 174 | STMFD r13!,{r10,r14} |
| 175 | |
| 176 | LDR r14,[r0,#12] @ r14= head |
| 177 | @ stall |
| 178 | adv_slow_loop: |
| 179 | LDR r1,[r0,#20] @ r1 = count |
| 180 | LDR r10,[r14,#8] @ r10= head->length |
| 181 | LDR r14,[r14,#12] @ r14= head->next |
| 182 | @ stall |
| 183 | ADD r1,r1,r10 @ r1 = count += head->length |
| 184 | CMP r14,#0 |
| 185 | BEQ adv_end |
| 186 | STR r1,[r0,#20] @ b->count = count |
| 187 | STR r14,[r0,#12] @ b->head = head |
| 188 | LDMIA r14,{r3,r10,r12} @ r3 = buffer |
| 189 | @ r10= begin |
| 190 | @ r12= length |
| 191 | LDR r3,[r3] @ r3 = buffer->data |
| 192 | ADD r3,r3,r10 @ r3 = Pointer to start (byte) |
| 193 | AND r10,r3,#3 @ r10= bytes to backtrk to word align |
| 194 | MOV r10,r10,LSL #3 @ r10= bits to backtrk to word align |
| 195 | RSB r10,r10,#32 @ r10= bits left in word |
| 196 | ADDS r10,r10,r2 @ r10= bits left in word after skip |
| 197 | ADDLE r10,r10,#32 |
| 198 | ADDLE r3,r3,#4 |
| 199 | BIC r3,r3,#3 @ r3 = Pointer to start (word) |
| 200 | ADDS r2,r2,r12,LSL #3 @ r2 = length in bits after advance |
| 201 | BLE adv_slow_loop |
| 202 | STMIA r0,{r2,r3,r10} |
| 203 | |
| 204 | LDMFD r13!,{r10,PC} |
| 205 | adv_end: |
| 206 | MOV r2, #0 |
| 207 | MOV r12,#0 |
| 208 | STMIA r0,{r2,r3,r12} |
| 209 | |
| 210 | LDMFD r13!,{r10,PC} |
| 211 | |
| 212 | oggpack_readinit: |
| 213 | @ r0 = oggpack_buffer *b |
| 214 | @ r1 = oggreference *r |
| 215 | STR r1,[r0,#12] @ b->head = r1 |
| 216 | STR r1,[r0,#16] @ b->tail = r1 |
| 217 | LDMIA r1,{r2,r3,r12} @ r2 = b->head->buffer |
| 218 | @ r3 = b->head->begin |
| 219 | @ r12= b->head->length |
| 220 | LDR r2,[r2] @ r2 = b->head->buffer->data |
| 221 | MOV r1,r12,LSL #3 @ r1 = BitsInSegment |
| 222 | MOV r12,#0 |
| 223 | ADD r3,r2,r3 @ r3 = r2+b->head->begin |
| 224 | BIC r2,r3,#3 @ r2 = b->headptr (word) |
| 225 | AND r3,r3,#3 |
| 226 | MOV r3,r3,LSL #3 |
| 227 | RSB r3,r3,#32 @ r3 = BitsInWord |
| 228 | STMIA r0,{r1,r2,r3} |
| 229 | STR r12,[r0,#20] |
Andreas Huber | 9a68875 | 2010-06-23 10:01:39 -0700 | [diff] [blame] | 230 | BX LR |
Gloria Wang | 7913073 | 2010-02-08 14:41:04 -0800 | [diff] [blame] | 231 | |
| 232 | oggpack_read: |
| 233 | @ r0 = oggpack_buffer *b |
| 234 | @ r1 = int bits |
| 235 | STMFD r13!,{r10,r11,r14} |
| 236 | LDMIA r0,{r2,r3,r12} |
| 237 | @ r2 = bitsLeftInSegment |
| 238 | @ r3 = ptr |
| 239 | @ r12= bitsLeftInWord |
| 240 | SUBS r2,r2,r1 @ bitsLeftinSegment -= bits |
| 241 | BLT read_slow @ Not enough bits in this segment for |
| 242 | @ this request. Do it slowly. |
| 243 | LDR r10,[r3] @ r10= ptr[0] |
| 244 | RSB r14,r12,#32 @ r14= 32-bitsLeftInWord |
| 245 | SUBS r12,r12,r1 @ r12= bitsLeftInWord -= bits |
| 246 | ADDLE r3,r3,#4 |
| 247 | LDRLT r11,[r3] @ r11= ptr[1] |
| 248 | MOV r10,r10,LSR r14 @ r10= ptr[0]>>(32-bitsLeftInWord) |
| 249 | ADDLE r12,r12,#32 @ r12= bitsLeftInWord += 32 |
| 250 | RSB r14,r14,#32 @ r14= 32-bitsLeftInWord |
| 251 | ORRLT r10,r10,r11,LSL r14 @ r10= Next 32 bits. |
| 252 | STMIA r0,{r2,r3,r12} |
| 253 | MOV r14,#1 |
| 254 | RSB r14,r14,r14,LSL r1 |
| 255 | AND r0,r10,r14 |
| 256 | LDMFD r13!,{r10,r11,PC} |
| 257 | |
| 258 | read_slow: |
| 259 | STMFD r13!,{r5,r6} |
| 260 | ADDS r10,r2,r1 @ r10= bitsLeftInSegment + bits (i.e. |
| 261 | @ the initial value of bitsLeftInSeg) |
| 262 | @ r10 = bitsLeftInSegment (initial) |
| 263 | @ r12 = bitsLeftInWord |
| 264 | RSB r14,r12,#32 @ r14= 32-bitsLeftInWord |
| 265 | MOV r5,r10 @ r5 = bitsLeftInSegment (initial) |
| 266 | BLT read_overrun |
| 267 | BEQ read_next_segment @ r10= r12 = 0, if we branch |
| 268 | CMP r12,r10 @ If bitsLeftInWord < bitsLeftInSeg |
| 269 | @ there must be more in the next word |
| 270 | LDR r10,[r3],#4 @ r10= ptr[0] |
| 271 | LDRLT r6,[r3] @ r6 = ptr[1] |
| 272 | MOV r11,#1 |
| 273 | MOV r10,r10,LSR r14 @ r10= first bitsLeftInWord bits |
| 274 | ORRLT r10,r10,r6,LSL r12 @ r10= first bitsLeftInSeg bits+crap |
| 275 | RSB r11,r11,r11,LSL r5 @ r11= mask |
| 276 | AND r10,r10,r11 @ r10= first r5 bits |
| 277 | @ Load the next segments data |
| 278 | read_next_segment: |
| 279 | @ At this point, r10 contains the first r5 bits of the result |
| 280 | LDR r11,[r0,#12] @ r11= head = b->head |
| 281 | @ Stall |
| 282 | read_next_segment_2: |
| 283 | @ r11 = head |
| 284 | LDR r6,[r0,#20] @ r6 = count |
| 285 | LDR r12,[r11,#8] @ r12= length |
| 286 | LDR r11,[r11,#12] @ r11= head = head->next |
| 287 | @ Stall |
| 288 | ADD r6,r6,r12 @ count += length |
| 289 | CMP r11,#0 |
| 290 | BEQ read_out_of_data |
| 291 | STR r11,[r0,#12] |
| 292 | STR r6,[r0,#20] @ b->count = count |
| 293 | LDMIA r11,{r6,r12,r14} @ r6 = buffer |
| 294 | @ r12= begin |
| 295 | @ r14= length |
| 296 | LDR r6,[r6] @ r6 = buffer->data |
| 297 | CMP r14,#0 |
| 298 | BEQ read_next_segment_2 |
| 299 | ADD r6,r6,r12 @ r6 = buffer->data+begin |
| 300 | read_slow_loop: |
| 301 | LDRB r12,[r6],#1 @ r12= *buffer |
| 302 | SUBS r14,r14,#1 @ r14= length |
| 303 | @ Stall |
| 304 | ORR r10,r10,r12,LSL r5 @ r10= first r5+8 bits |
| 305 | ADD r5,r5,#8 |
| 306 | BLE read_really_slow |
| 307 | CMP r5,r1 |
| 308 | BLT read_slow_loop |
| 309 | read_end: |
| 310 | MOV r12,#1 |
| 311 | RSB r12,r12,r12,LSL r1 |
| 312 | |
| 313 | @ Store back the new position |
| 314 | @ r2 = -number of bits to go from this segment |
| 315 | @ r6 = ptr |
| 316 | @ r14= bytesLeftInSegment |
| 317 | @ r11= New head value |
| 318 | LDMIA r11,{r3,r6,r14} @ r3 = buffer |
| 319 | @ r6 = begin |
| 320 | @ r14= length |
| 321 | LDR r3,[r3] @ r3 = buffer->data |
| 322 | ADD r1,r2,r14,LSL #3 @ r1 = bitsLeftInSegment |
| 323 | @ stall |
| 324 | ADD r6,r3,r6 @ r6 = pointer |
| 325 | AND r3,r6,#3 @ r3 = bytes used in first word |
| 326 | RSB r3,r2,r3,LSL #3 @ r3 = bits used in first word |
| 327 | BIC r2,r6,#3 @ r2 = word ptr |
| 328 | RSBS r3,r3,#32 @ r3 = bitsLeftInWord |
| 329 | ADDLE r3,r3,#32 |
| 330 | ADDLE r2,r2,#4 |
| 331 | STMIA r0,{r1,r2,r3} |
| 332 | |
| 333 | AND r0,r10,r12 |
| 334 | LDMFD r13!,{r5,r6,r10,r11,PC} |
| 335 | |
| 336 | |
| 337 | read_really_slow: |
| 338 | CMP r5,r1 |
| 339 | BGE read_end |
| 340 | LDR r14,[r11,#8] @ r14= length of segment just done |
| 341 | @ stall |
| 342 | @ stall |
| 343 | ADD r2,r2,r14,LSL #3 @ r2 = -bits to use from next seg |
| 344 | B read_next_segment_2 |
| 345 | |
| 346 | read_out_of_data: |
| 347 | @ Store back the new position |
| 348 | @ r2 = -number of bits to go from this segment |
| 349 | @ r6 = ptr |
| 350 | @ r14= bytesLeftInSegment |
| 351 | @ RJW: This may be overkill - we leave the buffer empty, with -1 |
| 352 | @ bits left in it. We might get away with just storing the |
| 353 | @ bitsLeftInSegment as -1. |
| 354 | LDR r11,[r0,#12] @ r11=head |
| 355 | |
| 356 | LDMIA r11,{r3,r6,r14} @ r3 = buffer |
| 357 | @ r6 = begin |
| 358 | @ r14= length |
| 359 | LDR r3,[r3] @ r3 = buffer->data |
| 360 | ADD r6,r3,r6 @ r6 = pointer |
| 361 | ADD r6,r6,r14 |
| 362 | AND r3,r6,#3 @ r3 = bytes used in first word |
| 363 | MOV r3,r3,LSL #3 @ r3 = bits used in first word |
| 364 | BIC r2,r6,#3 @ r2 = word ptr |
| 365 | RSBS r3,r3,#32 @ r3 = bitsLeftInWord |
| 366 | MVN r1,#0 @ r1 = -1 = bitsLeftInSegment |
| 367 | STMIA r0,{r1,r2,r3} |
| 368 | @MVN r0,#0 ; return -1 |
| 369 | MOV r0,#0 |
| 370 | LDMFD r13!,{r5,r6,r10,r11,PC} |
| 371 | |
| 372 | read_overrun: |
| 373 | @ We had overrun when we started, so we need to skip -r10 bits. |
| 374 | LDR r11,[r0,#12] @ r11 = head = b->head |
| 375 | @ stall |
| 376 | @ stall |
| 377 | read_overrun_next_segment: |
| 378 | LDR r11,[r11,#12] @ r11 = head->next |
| 379 | @ stall |
| 380 | @ stall |
| 381 | CMP r11,#0 |
| 382 | BEQ read_out_of_data |
| 383 | LDMIA r11,{r6,r7,r14} @ r6 = buffer |
| 384 | @ r7 = begin |
| 385 | @ r14= length |
| 386 | LDR r6,[r6] @ r6 = buffer->data |
| 387 | @ stall |
| 388 | @ stall |
| 389 | ADD r6,r6,r7 @ r6 = buffer->data+begin |
| 390 | MOV r14,r14,LSL #3 @ r14= length in bits |
| 391 | ADDS r14,r14,r10 @ r14= length in bits-bits to skip |
| 392 | MOVLE r10,r14 |
| 393 | BLE read_overrun_next_segment |
| 394 | RSB r10,r10,#0 @ r10= bits to skip |
| 395 | ADD r6,r10,r10,LSR #3 @ r6 = pointer to data |
| 396 | MOV r10,#0 |
| 397 | B read_slow_loop |
| 398 | |
| 399 | @ END |