File: memcpy.S

package info (click to toggle)
glibc 2.19-18+deb8u7
  • links: PTS, VCS
  • area: main
  • in suites: jessie-backports
  • size: 204,748 kB
  • sloc: ansic: 970,427; asm: 241,207; sh: 10,069; makefile: 8,476; cpp: 3,595; perl: 2,077; pascal: 1,839; awk: 1,704; yacc: 317; sed: 73
file content (584 lines) | stat: -rw-r--r-- 10,217 bytes parent folder | download | duplicates (10)
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
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
/*
   Optimized memcpy for x86-64.

   Copyright (C) 2007-2014 Free Software Foundation, Inc.
   Contributed by Evandro Menezes <evandro.menezes@amd.com>, 2007.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.
*/

#include <sysdep.h>
#include "asm-syntax.h"

/* Stack slots in the red-zone. */

#ifdef USE_AS_MEMPCPY
#  define RETVAL	(0)
#else
#  define RETVAL	(-8)
#  if defined SHARED && !defined USE_MULTIARCH && !defined NOT_IN_libc
#    define memcpy	__memcpy
#    undef libc_hidden_builtin_def
#    define libc_hidden_builtin_def(name) \
	.globl __GI_memcpy; __GI_memcpy = __memcpy
#  endif
#endif
#define SAVE0	(RETVAL - 8)
#define SAVE1	(SAVE0	- 8)
#define SAVE2	(SAVE1	- 8)
#define SAVE3	(SAVE2	- 8)

        .text

#if defined PIC && !defined NOT_IN_libc
ENTRY_CHK (__memcpy_chk)

	cmpq	%rdx, %rcx
	jb	HIDDEN_JUMPTARGET (__chk_fail)

END_CHK (__memcpy_chk)
#endif

ENTRY(memcpy)				/* (void *, const void*, size_t) */

/* Handle tiny blocks. */

L(1try):				/* up to 32B */
	cmpq	$32, %rdx
#ifndef USE_AS_MEMPCPY
	movq	%rdi, %rax		/* save return value */
#endif
	jae	L(1after)

L(1):					/* 1-byte once */
	testb	$1, %dl
	jz	L(1a)

	movzbl	(%rsi),	%ecx
	movb	%cl, (%rdi)

	incq	%rsi
	incq	%rdi

	.p2align 4,, 4

L(1a):					/* 2-byte once */
	testb	$2, %dl
	jz	L(1b)

	movzwl	(%rsi),	%ecx
	movw	%cx, (%rdi)

	addq	$2, %rsi
	addq	$2, %rdi

	.p2align 4,, 4

L(1b):					/* 4-byte once */
	testb	$4, %dl
	jz	L(1c)

	movl	(%rsi),	%ecx
	movl	%ecx, (%rdi)

	addq	$4, %rsi
	addq	$4, %rdi

	.p2align 4,, 4

L(1c):					/* 8-byte once */
	testb	$8, %dl
	jz	L(1d)

	movq	(%rsi), %rcx
	movq	%rcx, (%rdi)

	addq	$8, %rsi
	addq	$8, %rdi

	.p2align 4,, 4

L(1d):					/* 16-byte loop */
	andl	$0xf0, %edx
	jz	L(exit)

	.p2align 4

L(1loop):
	movq	 (%rsi), %rcx
	movq	8(%rsi), %r8
	movq	%rcx,  (%rdi)
	movq	 %r8, 8(%rdi)

	subl	$16, %edx

	leaq	16(%rsi), %rsi
	leaq	16(%rdi), %rdi

	jnz	L(1loop)

	.p2align 4,, 4

L(exit):				/* exit */
#ifdef USE_AS_MEMPCPY
	movq	%rdi, %rax		/* return value */
#else
	rep
#endif
	retq

	.p2align 4

L(1after):
#ifndef USE_AS_MEMPCPY
	movq	%rax, RETVAL(%rsp)	/* save return value */
#endif

/* Align to the natural word size. */

L(aligntry):
	movl	%esi, %ecx      	/* align by source */

	andl	$7, %ecx
	jz	L(alignafter)  		/* already aligned */

L(align):		      		/* align */
	leaq	-8(%rcx, %rdx), %rdx	/* calculate remaining bytes */
	subl	$8, %ecx

	.p2align 4

L(alignloop):				/* 1-byte alignment loop */
	movzbl	(%rsi), %eax
	movb	%al, (%rdi)

	incl	%ecx

	leaq	1(%rsi), %rsi
	leaq	1(%rdi), %rdi

	jnz	L(alignloop)

	.p2align 4

L(alignafter):

/* Handle mid-sized blocks. */

L(32try):				/* up to 1KB */
	cmpq	$1024, %rdx
	ja	L(32after)

L(32):					/* 32-byte loop */
	movl	%edx, %ecx
	shrl	$5, %ecx
	jz	L(32skip)

	.p2align 4

L(32loop):
	decl	%ecx

	movq	  (%rsi), %rax
	movq	 8(%rsi), %r8
	movq	16(%rsi), %r9
	movq	24(%rsi), %r10

	movq	%rax,   (%rdi)
	movq	 %r8,  8(%rdi)
	movq	 %r9, 16(%rdi)
	movq	%r10, 24(%rdi)

	leaq	32(%rsi), %rsi
	leaq	32(%rdi), %rdi

	jz	L(32skip)		/* help out smaller blocks */

	decl	%ecx

	movq	  (%rsi), %rax
	movq	 8(%rsi), %r8
	movq	16(%rsi), %r9
	movq	24(%rsi), %r10

	movq	%rax,   (%rdi)
	movq	 %r8,  8(%rdi)
	movq	 %r9, 16(%rdi)
	movq	%r10, 24(%rdi)

	leaq	32(%rsi), %rsi
	leaq	32(%rdi), %rdi

	jnz	L(32loop)

	.p2align 4

L(32skip):
	andl	$31, %edx		/* check for left overs */
#ifdef USE_AS_MEMPCPY
	jnz	L(1)

	movq	%rdi, %rax
#else
	movq	RETVAL(%rsp), %rax
	jnz	L(1)

	rep
#endif
	retq				/* exit */

	.p2align 4

L(32after):

/*
	In order to minimize code-size in RTLD, algorithms specific for
	larger blocks are excluded when building for RTLD.
*/

/* Handle blocks smaller than 1/2 L1. */

L(fasttry):				/* first 1/2 L1 */
#ifndef NOT_IN_libc			/* only up to this algorithm outside of libc.so */
	mov	__x86_data_cache_size_half(%rip), %R11_LP
	cmpq	%rdx, %r11		/* calculate the smaller of */
	cmovaq	%rdx, %r11		/* remaining bytes and 1/2 L1 */
#endif

L(fast):				/* good ol' MOVS */
#ifndef NOT_IN_libc
	movq	%r11, %rcx
	andq	$-8, %r11
#else
	movq	%rdx, %rcx
#endif
	shrq	$3, %rcx
	jz	L(fastskip)

	rep
	movsq

	.p2align 4,, 4

L(fastskip):
#ifndef NOT_IN_libc
	subq	%r11, %rdx		/* check for more */
	testq	$-8, %rdx
	jnz	L(fastafter)
#endif

	andl	$7, %edx		/* check for left overs */
#ifdef USE_AS_MEMPCPY
	jnz	L(1)

	movq	%rdi, %rax
#else
	movq	RETVAL(%rsp), %rax
	jnz	L(1)

	rep
#endif
	retq				/* exit */

#ifndef NOT_IN_libc			/* none of the algorithms below for RTLD */

	.p2align 4

L(fastafter):

/* Handle large blocks smaller than 1/2 L2. */

L(pretry):				/* first 1/2 L2 */
	mov	__x86_shared_cache_size_half (%rip), %R8_LP
	cmpq	%rdx, %r8		/* calculate the lesser of */
	cmovaq	%rdx, %r8		/* remaining bytes and 1/2 L2 */

L(pre):					/* 64-byte with prefetching */
	movq	%r8, %rcx
	andq	$-64, %r8
	shrq	$6, %rcx
	jz	L(preskip)

	movq	%r14, SAVE0(%rsp)
	cfi_rel_offset (%r14, SAVE0)
	movq	%r13, SAVE1(%rsp)
	cfi_rel_offset (%r13, SAVE1)
	movq	%r12, SAVE2(%rsp)
	cfi_rel_offset (%r12, SAVE2)
	movq	%rbx, SAVE3(%rsp)
	cfi_rel_offset (%rbx, SAVE3)

	cmpl	$0, __x86_prefetchw(%rip)
	jz	L(preloop)		/* check if PREFETCHW OK */

	.p2align 4

/* ... when PREFETCHW is available (less cache-probe traffic in MP systems). */

L(prewloop):				/* cache-line in state M */
	decq	%rcx

	movq	   (%rsi), %rax
	movq	 8 (%rsi), %rbx
	movq	16 (%rsi), %r9
	movq	24 (%rsi), %r10
	movq	32 (%rsi), %r11
	movq	40 (%rsi), %r12
	movq	48 (%rsi), %r13
	movq	56 (%rsi), %r14

	prefetcht0	 0 + 896 (%rsi)
	prefetcht0	64 + 896 (%rsi)

	movq	%rax,   (%rdi)
	movq	%rbx,  8(%rdi)
	movq	 %r9, 16(%rdi)
	movq	%r10, 24(%rdi)
	movq	%r11, 32(%rdi)
	movq	%r12, 40(%rdi)
	movq	%r13, 48(%rdi)
	movq	%r14, 56(%rdi)

	leaq	64(%rsi), %rsi
	leaq	64(%rdi), %rdi

	jz	L(prebail)

	decq	%rcx

	movq	  (%rsi), %rax
	movq	 8(%rsi), %rbx
	movq	16(%rsi), %r9
	movq	24(%rsi), %r10
	movq	32(%rsi), %r11
	movq	40(%rsi), %r12
	movq	48(%rsi), %r13
	movq	56(%rsi), %r14

	movq	%rax,   (%rdi)
	movq	%rbx,  8(%rdi)
	movq	 %r9, 16(%rdi)
	movq	%r10, 24(%rdi)
	movq	%r11, 32(%rdi)
	movq	%r12, 40(%rdi)
	movq	%r13, 48(%rdi)
	movq	%r14, 56(%rdi)

	prefetchw	896 - 64(%rdi)
	prefetchw	896 -  0(%rdi)

	leaq	64(%rsi), %rsi
	leaq	64(%rdi), %rdi

	jnz	L(prewloop)
	jmp	L(prebail)

	.p2align 4

/* ... when PREFETCHW is not available. */

L(preloop):				/* cache-line in state E */
	decq	%rcx

	movq	  (%rsi), %rax
	movq	 8(%rsi), %rbx
	movq	16(%rsi), %r9
	movq	24(%rsi), %r10
	movq	32(%rsi), %r11
	movq	40(%rsi), %r12
	movq	48(%rsi), %r13
	movq	56(%rsi), %r14

	prefetcht0	896 +  0(%rsi)
	prefetcht0	896 + 64(%rsi)

	movq	%rax,   (%rdi)
	movq	%rbx,  8(%rdi)
	movq	 %r9, 16(%rdi)
	movq	%r10, 24(%rdi)
	movq	%r11, 32(%rdi)
	movq	%r12, 40(%rdi)
	movq	%r13, 48(%rdi)
	movq	%r14, 56(%rdi)

	leaq	64 (%rsi), %rsi
	leaq	64 (%rdi), %rdi

	jz	L(prebail)

	decq	%rcx

	movq	  (%rsi), %rax
	movq	 8(%rsi), %rbx
	movq	16(%rsi), %r9
	movq	24(%rsi), %r10
	movq	32(%rsi), %r11
	movq	40(%rsi), %r12
	movq	48(%rsi), %r13
	movq	56(%rsi), %r14

	prefetcht0	896 - 64(%rdi)
	prefetcht0	896 -  0(%rdi)

	movq	%rax,   (%rdi)
	movq	%rbx,  8(%rdi)
	movq	 %r9, 16(%rdi)
	movq	%r10, 24(%rdi)
	movq	%r11, 32(%rdi)
	movq	%r12, 40(%rdi)
	movq	%r13, 48(%rdi)
	movq	%r14, 56(%rdi)

	leaq	64(%rsi), %rsi
	leaq	64(%rdi), %rdi

	jnz	L(preloop)

L(prebail):
	movq	SAVE3(%rsp), %rbx
	cfi_restore (%rbx)
	movq	SAVE2(%rsp), %r12
	cfi_restore (%r12)
	movq	SAVE1(%rsp), %r13
	cfi_restore (%r13)
	movq	SAVE0(%rsp), %r14
	cfi_restore (%r14)

/*       .p2align 4 */

L(preskip):
	subq	%r8, %rdx		/* check for more */
	testq	$-64, %rdx
	jnz	L(preafter)

	andl	$63, %edx		/* check for left overs */
#ifdef USE_AS_MEMPCPY
	jnz	L(1)

	movq	%rdi, %rax
#else
	movq	RETVAL(%rsp), %rax
	jnz	L(1)

	rep
#endif
	retq				/* exit */

	.p2align 4

L(preafter):

/* Handle huge blocks. */

L(NTtry):

L(NT):					/* non-temporal 128-byte */
	movq	%rdx, %rcx
	shrq	$7, %rcx
	jz	L(NTskip)

	movq	%r14, SAVE0(%rsp)
	cfi_rel_offset (%r14, SAVE0)
	movq	%r13, SAVE1(%rsp)
	cfi_rel_offset (%r13, SAVE1)
	movq	%r12, SAVE2(%rsp)
	cfi_rel_offset (%r12, SAVE2)

       .p2align 4

L(NTloop):
	prefetchnta	768(%rsi)
	prefetchnta	832(%rsi)

	decq	%rcx

	movq	  (%rsi), %rax
	movq	 8(%rsi), %r8
	movq	16(%rsi), %r9
	movq	24(%rsi), %r10
	movq	32(%rsi), %r11
	movq	40(%rsi), %r12
	movq	48(%rsi), %r13
	movq	56(%rsi), %r14

	movntiq	%rax,   (%rdi)
	movntiq	 %r8,  8(%rdi)
	movntiq	 %r9, 16(%rdi)
	movntiq	%r10, 24(%rdi)
	movntiq	%r11, 32(%rdi)
	movntiq	%r12, 40(%rdi)
	movntiq	%r13, 48(%rdi)
	movntiq	%r14, 56(%rdi)

	movq	 64(%rsi), %rax
	movq	 72(%rsi), %r8
	movq	 80(%rsi), %r9
	movq	 88(%rsi), %r10
	movq	 96(%rsi), %r11
	movq	104(%rsi), %r12
	movq	112(%rsi), %r13
	movq	120(%rsi), %r14

	movntiq	%rax,  64(%rdi)
	movntiq	 %r8,  72(%rdi)
	movntiq	 %r9,  80(%rdi)
	movntiq	%r10,  88(%rdi)
	movntiq	%r11,  96(%rdi)
	movntiq	%r12, 104(%rdi)
	movntiq	%r13, 112(%rdi)
	movntiq	%r14, 120(%rdi)

	leaq	128(%rsi), %rsi
	leaq	128(%rdi), %rdi

	jnz	L(NTloop)

	sfence				/* serialize memory stores */

	movq	SAVE2(%rsp), %r12
	cfi_restore (%r12)
	movq	SAVE1(%rsp), %r13
	cfi_restore (%r13)
	movq	SAVE0(%rsp), %r14
	cfi_restore (%r14)

L(NTskip):
	andl	$127, %edx		/* check for left overs */
#ifdef USE_AS_MEMPCPY
	jnz	L(1)

	movq	%rdi, %rax
#else
	movq	RETVAL(%rsp), %rax
	jnz	L(1)

	rep
#endif
	retq				/* exit */

#endif /* !NOT_IN_libc */

END(memcpy)

#ifndef USE_AS_MEMPCPY
libc_hidden_builtin_def (memcpy)
# if defined SHARED && !defined USE_MULTIARCH && !defined NOT_IN_libc
#  undef memcpy
#  include <shlib-compat.h>
versioned_symbol (libc, __memcpy, memcpy, GLIBC_2_14);
# endif
#endif