1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
|
/*
* Copyright (C) 2013 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Copyright (c) 2013 ARM Ltd
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the company may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#if !defined(STPCPY) && !defined(STRCPY)
#error "Either STPCPY or STRCPY must be defined."
#endif
#include <private/bionic_asm.h>
.syntax unified
.thumb
.thumb_func
#if defined(STPCPY)
.macro m_push
push {r4, r5, lr}
.cfi_def_cfa_offset 12
.cfi_rel_offset r4, 0
.cfi_rel_offset r5, 4
.cfi_rel_offset lr, 8
.endm // m_push
#else
.macro m_push
push {r0, r4, r5, lr}
.cfi_def_cfa_offset 16
.cfi_rel_offset r0, 0
.cfi_rel_offset r4, 4
.cfi_rel_offset r5, 8
.cfi_rel_offset lr, 12
.endm // m_push
#endif
#if defined(STPCPY)
.macro m_pop
pop {r4, r5, pc}
.endm // m_pop
#else
.macro m_pop
pop {r0, r4, r5, pc}
.endm // m_pop
#endif
.macro m_copy_byte reg, cmd, label
ldrb \reg, [r1], #1
strb \reg, [r0], #1
\cmd \reg, \label
.endm // m_copy_byte
#if defined(STPCPY)
ENTRY(stpcpy)
#else
ENTRY(strcpy)
#endif
// For short copies, hard-code checking the first 8 bytes since this
// new code doesn't win until after about 8 bytes.
m_push
m_copy_byte reg=r2, cmd=cbz, label=.Lstringcopy_finish
m_copy_byte reg=r3, cmd=cbz, label=.Lstringcopy_finish
m_copy_byte reg=r4, cmd=cbz, label=.Lstringcopy_finish
m_copy_byte reg=r5, cmd=cbz, label=.Lstringcopy_finish
m_copy_byte reg=r2, cmd=cbz, label=.Lstringcopy_finish
m_copy_byte reg=r3, cmd=cbz, label=.Lstringcopy_finish
m_copy_byte reg=r4, cmd=cbz, label=.Lstringcopy_finish
m_copy_byte reg=r5, cmd=cbnz, label=.Lstringcopy_continue
.Lstringcopy_finish:
#if defined(STPCPY)
sub r0, r0, #1
#endif
m_pop
.Lstringcopy_continue:
pld [r1, #0]
ands r3, r0, #7
beq .Lstringcopy_check_src_align
// Align to a double word (64 bits).
rsb r3, r3, #8
lsls ip, r3, #31
beq .Lstringcopy_align_to_32
ldrb r2, [r1], #1
strb r2, [r0], #1
cbz r2, .Lstringcopy_complete
.Lstringcopy_align_to_32:
bcc .Lstringcopy_align_to_64
ldrb r2, [r1], #1
strb r2, [r0], #1
cbz r2, .Lstringcopy_complete
ldrb r2, [r1], #1
strb r2, [r0], #1
cbz r2, .Lstringcopy_complete
.Lstringcopy_align_to_64:
tst r3, #4
beq .Lstringcopy_check_src_align
ldr r2, [r1], #4
sub ip, r2, #0x01010101
bic ip, ip, r2
ands ip, ip, #0x80808080
bne .Lstringcopy_zero_in_first_register
str r2, [r0], #4
.Lstringcopy_check_src_align:
// At this point dst is aligned to a double word, check if src
// is also aligned to a double word.
ands r3, r1, #7
bne .Lstringcopy_unaligned_copy
.p2align 2
.Lstringcopy_mainloop:
ldrd r2, r3, [r1], #8
pld [r1, #64]
sub ip, r2, #0x01010101
bic ip, ip, r2
ands ip, ip, #0x80808080
bne .Lstringcopy_zero_in_first_register
sub ip, r3, #0x01010101
bic ip, ip, r3
ands ip, ip, #0x80808080
bne .Lstringcopy_zero_in_second_register
strd r2, r3, [r0], #8
b .Lstringcopy_mainloop
.Lstringcopy_complete:
#if defined(STPCPY)
sub r0, r0, #1
#endif
m_pop
.Lstringcopy_zero_in_first_register:
lsls lr, ip, #17
bne .Lstringcopy_copy1byte
bcs .Lstringcopy_copy2bytes
lsls ip, ip, #1
bne .Lstringcopy_copy3bytes
.Lstringcopy_copy4bytes:
// Copy 4 bytes to the destiniation.
#if defined(STPCPY)
str r2, [r0], #3
#else
str r2, [r0]
#endif
m_pop
.Lstringcopy_copy1byte:
strb r2, [r0]
m_pop
.Lstringcopy_copy2bytes:
#if defined(STPCPY)
strh r2, [r0], #1
#else
strh r2, [r0]
#endif
m_pop
.Lstringcopy_copy3bytes:
strh r2, [r0], #2
lsr r2, #16
strb r2, [r0]
m_pop
.Lstringcopy_zero_in_second_register:
lsls lr, ip, #17
bne .Lstringcopy_copy5bytes
bcs .Lstringcopy_copy6bytes
lsls ip, ip, #1
bne .Lstringcopy_copy7bytes
// Copy 8 bytes to the destination.
strd r2, r3, [r0]
#if defined(STPCPY)
add r0, r0, #7
#endif
m_pop
.Lstringcopy_copy5bytes:
str r2, [r0], #4
strb r3, [r0]
m_pop
.Lstringcopy_copy6bytes:
str r2, [r0], #4
#if defined(STPCPY)
strh r3, [r0], #1
#else
strh r3, [r0]
#endif
m_pop
.Lstringcopy_copy7bytes:
str r2, [r0], #4
strh r3, [r0], #2
lsr r3, #16
strb r3, [r0]
m_pop
.Lstringcopy_unaligned_copy:
// Dst is aligned to a double word, while src is at an unknown alignment.
// There are 7 different versions of the unaligned copy code
// to prevent overreading the src. The mainloop of every single version
// will store 64 bits per loop. The difference is how much of src can
// be read without potentially crossing a page boundary.
tbb [pc, r3]
.Lstringcopy_unaligned_branchtable:
.byte 0
.byte ((.Lstringcopy_unalign7 - .Lstringcopy_unaligned_branchtable)/2)
.byte ((.Lstringcopy_unalign6 - .Lstringcopy_unaligned_branchtable)/2)
.byte ((.Lstringcopy_unalign5 - .Lstringcopy_unaligned_branchtable)/2)
.byte ((.Lstringcopy_unalign4 - .Lstringcopy_unaligned_branchtable)/2)
.byte ((.Lstringcopy_unalign3 - .Lstringcopy_unaligned_branchtable)/2)
.byte ((.Lstringcopy_unalign2 - .Lstringcopy_unaligned_branchtable)/2)
.byte ((.Lstringcopy_unalign1 - .Lstringcopy_unaligned_branchtable)/2)
.p2align 2
// Can read 7 bytes before possibly crossing a page.
.Lstringcopy_unalign7:
ldr r2, [r1], #4
sub ip, r2, #0x01010101
bic ip, ip, r2
ands ip, ip, #0x80808080
bne .Lstringcopy_zero_in_first_register
ldrb r3, [r1]
cbz r3, .Lstringcopy_unalign7_copy5bytes
ldrb r4, [r1, #1]
cbz r4, .Lstringcopy_unalign7_copy6bytes
ldrb r5, [r1, #2]
cbz r5, .Lstringcopy_unalign7_copy7bytes
ldr r3, [r1], #4
pld [r1, #64]
lsrs ip, r3, #24
strd r2, r3, [r0], #8
#if defined(STPCPY)
beq .Lstringcopy_finish
#else
beq .Lstringcopy_unalign_return
#endif
b .Lstringcopy_unalign7
.Lstringcopy_unalign7_copy5bytes:
str r2, [r0], #4
strb r3, [r0]
.Lstringcopy_unalign_return:
m_pop
.Lstringcopy_unalign7_copy6bytes:
str r2, [r0], #4
strb r3, [r0], #1
strb r4, [r0]
m_pop
.Lstringcopy_unalign7_copy7bytes:
str r2, [r0], #4
strb r3, [r0], #1
strb r4, [r0], #1
strb r5, [r0]
m_pop
.p2align 2
// Can read 6 bytes before possibly crossing a page.
.Lstringcopy_unalign6:
ldr r2, [r1], #4
sub ip, r2, #0x01010101
bic ip, ip, r2
ands ip, ip, #0x80808080
bne .Lstringcopy_zero_in_first_register
ldrb r4, [r1]
cbz r4, .Lstringcopy_unalign_copy5bytes
ldrb r5, [r1, #1]
cbz r5, .Lstringcopy_unalign_copy6bytes
ldr r3, [r1], #4
pld [r1, #64]
tst r3, #0xff0000
beq .Lstringcopy_copy7bytes
lsrs ip, r3, #24
strd r2, r3, [r0], #8
#if defined(STPCPY)
beq .Lstringcopy_finish
#else
beq .Lstringcopy_unalign_return
#endif
b .Lstringcopy_unalign6
.p2align 2
// Can read 5 bytes before possibly crossing a page.
.Lstringcopy_unalign5:
ldr r2, [r1], #4
sub ip, r2, #0x01010101
bic ip, ip, r2
ands ip, ip, #0x80808080
bne .Lstringcopy_zero_in_first_register
ldrb r4, [r1]
cbz r4, .Lstringcopy_unalign_copy5bytes
ldr r3, [r1], #4
pld [r1, #64]
sub ip, r3, #0x01010101
bic ip, ip, r3
ands ip, ip, #0x80808080
bne .Lstringcopy_zero_in_second_register
strd r2, r3, [r0], #8
b .Lstringcopy_unalign5
.Lstringcopy_unalign_copy5bytes:
str r2, [r0], #4
strb r4, [r0]
m_pop
.Lstringcopy_unalign_copy6bytes:
str r2, [r0], #4
strb r4, [r0], #1
strb r5, [r0]
m_pop
.p2align 2
// Can read 4 bytes before possibly crossing a page.
.Lstringcopy_unalign4:
ldr r2, [r1], #4
sub ip, r2, #0x01010101
bic ip, ip, r2
ands ip, ip, #0x80808080
bne .Lstringcopy_zero_in_first_register
ldr r3, [r1], #4
pld [r1, #64]
sub ip, r3, #0x01010101
bic ip, ip, r3
ands ip, ip, #0x80808080
bne .Lstringcopy_zero_in_second_register
strd r2, r3, [r0], #8
b .Lstringcopy_unalign4
.p2align 2
// Can read 3 bytes before possibly crossing a page.
.Lstringcopy_unalign3:
ldrb r2, [r1]
cbz r2, .Lstringcopy_unalign3_copy1byte
ldrb r3, [r1, #1]
cbz r3, .Lstringcopy_unalign3_copy2bytes
ldrb r4, [r1, #2]
cbz r4, .Lstringcopy_unalign3_copy3bytes
ldr r2, [r1], #4
ldr r3, [r1], #4
pld [r1, #64]
lsrs lr, r2, #24
beq .Lstringcopy_copy4bytes
sub ip, r3, #0x01010101
bic ip, ip, r3
ands ip, ip, #0x80808080
bne .Lstringcopy_zero_in_second_register
strd r2, r3, [r0], #8
b .Lstringcopy_unalign3
.Lstringcopy_unalign3_copy1byte:
strb r2, [r0]
m_pop
.Lstringcopy_unalign3_copy2bytes:
strb r2, [r0], #1
strb r3, [r0]
m_pop
.Lstringcopy_unalign3_copy3bytes:
strb r2, [r0], #1
strb r3, [r0], #1
strb r4, [r0]
m_pop
.p2align 2
// Can read 2 bytes before possibly crossing a page.
.Lstringcopy_unalign2:
ldrb r2, [r1]
cbz r2, .Lstringcopy_unalign_copy1byte
ldrb r4, [r1, #1]
cbz r4, .Lstringcopy_unalign_copy2bytes
ldr r2, [r1], #4
ldr r3, [r1], #4
pld [r1, #64]
tst r2, #0xff0000
beq .Lstringcopy_copy3bytes
lsrs ip, r2, #24
beq .Lstringcopy_copy4bytes
sub ip, r3, #0x01010101
bic ip, ip, r3
ands ip, ip, #0x80808080
bne .Lstringcopy_zero_in_second_register
strd r2, r3, [r0], #8
b .Lstringcopy_unalign2
.p2align 2
// Can read 1 byte before possibly crossing a page.
.Lstringcopy_unalign1:
ldrb r2, [r1]
cbz r2, .Lstringcopy_unalign_copy1byte
ldr r2, [r1], #4
ldr r3, [r1], #4
pld [r1, #64]
sub ip, r2, #0x01010101
bic ip, ip, r2
ands ip, ip, #0x80808080
bne .Lstringcopy_zero_in_first_register
sub ip, r3, #0x01010101
bic ip, ip, r3
ands ip, ip, #0x80808080
bne .Lstringcopy_zero_in_second_register
strd r2, r3, [r0], #8
b .Lstringcopy_unalign1
.Lstringcopy_unalign_copy1byte:
strb r2, [r0]
m_pop
.Lstringcopy_unalign_copy2bytes:
strb r2, [r0], #1
strb r4, [r0]
m_pop
#if defined(STPCPY)
END(stpcpy)
#else
END(strcpy)
#endif
|