about summary refs log tree commit diff
path: root/sysdeps/powerpc/powerpc64/a2/memcpy.S
blob: 0e3c435f3c78625ea4c9207a9b61a8ed36f6f6bd (plain) (blame)
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
/* Optimized memcpy implementation for PowerPC A2.
   Copyright (C) 2010-2020 Free Software Foundation, Inc.
   Contributed by Michael Brutman <brutman@us.ibm.com>.
   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
   <https://www.gnu.org/licenses/>.  */

#include <sysdep.h>

#ifndef MEMCPY
# define MEMCPY memcpy
#endif

#define PREFETCH_AHEAD 4        /* no cache lines SRC prefetching ahead  */
#define ZERO_AHEAD 2            /* no cache lines DST zeroing ahead  */

	.section        ".toc","aw"
.LC0:
	.tc __cache_line_size[TC],__cache_line_size
	.section        ".text"
	.align 2


	.machine  a2
ENTRY (MEMCPY, 5)
	CALL_MCOUNT 3

	dcbt    0,r4            /* Prefetch ONE SRC cacheline  */
	cmpldi  cr1,r5,16       /* is size < 16 ?  */
	mr      r6,r3           /* Copy dest reg to r6; */
	blt+    cr1,L(shortcopy)


	/* Big copy (16 bytes or more)

	   Figure out how far to the nearest quadword boundary, or if we are
	   on one already.  Also get the cache line size.

	   r3 - return value (always)
	   r4 - current source addr
	   r5 - copy length
	   r6 - current dest addr
	*/

	neg     r8,r3           /* LS 4 bits = # bytes to 8-byte dest bdry  */
	ld      r9,.LC0@toc(r2) /* Get cache line size (part 1) */
	clrldi  r8,r8,64-4      /* align to 16byte boundary  */
	sub     r7,r4,r3        /* compute offset to src from dest */
	lwz     r9,0(r9)        /* Get cache line size (part 2) */
	cmpldi  cr0,r8,0        /* Were we aligned on a 16 byte bdy? */
	addi    r10,r9,-1       /* Cache line mask */
	beq+    L(dst_aligned)



	/* Destination is not aligned on quadword boundary.  Get us to one.

	   r3 - return value (always)
	   r4 - current source addr
	   r5 - copy length
	   r6 - current dest addr
	   r7 - offset to src from dest
	   r8 - number of bytes to quadword boundary
	*/

	mtcrf   0x01,r8         /* put #bytes to boundary into cr7  */
	subf    r5,r8,r5        /* adjust remaining len */

	bf      cr7*4+3,1f
	lbzx    r0,r7,r6        /* copy 1 byte addr */
	stb     r0,0(r6)
	addi    r6,r6,1
1:
	bf      cr7*4+2,2f
	lhzx    r0,r7,r6        /* copy 2 byte addr */
	sth     r0,0(r6)
	addi    r6,r6,2
2:
	bf      cr7*4+1,4f
	lwzx    r0,r7,r6        /* copy 4 byte addr */
	stw     r0,0(r6)
	addi    r6,r6,4
4:
	bf      cr7*4+0,8f
	ldx     r0,r7,r6        /* copy 8 byte addr */
	std     r0,0(r6)
	addi    r6,r6,8
8:
	add     r4,r7,r6        /* update src addr */



	/* Dest is quadword aligned now.

	   Lots of decisions to make.  If we are copying less than a cache
	   line we won't be here long.  If we are not on a cache line
	   boundary we need to get there.  And then we need to figure out
	   how many cache lines ahead to pre-touch.

	   r3 - return value (always)
	   r4 - current source addr
	   r5 - copy length
	   r6 - current dest addr
	*/


	.align 4
L(dst_aligned):
	cmpdi	cr0,r9,0	/* Cache line size set? */
	bne+	cr0,L(cachelineset)

/* __cache_line_size not set: generic byte copy without much optimization */
	clrldi.	r0,r5,63	/* If length is odd copy one byte */
	beq	L(cachelinenotset_align)
	lbz	r7,0(r4)	/* Read one byte from source */
	addi	r5,r5,-1	/* Update length */
	addi	r4,r4,1		/* Update source pointer address */
	stb	r7,0(r6)	/* Store one byte at dest */
	addi	r6,r6,1		/* Update dest pointer address */
L(cachelinenotset_align):
	cmpdi	cr7,r5,0	/* If length is 0 return */
	beqlr	cr7
	ori	r2,r2,0		/* Force a new dispatch group */
L(cachelinenotset_loop):
	addic.	r5,r5,-2	/* Update length */
	lbz	r7,0(r4)	/* Load 2 bytes from source */
	lbz	r8,1(r4)
	addi	r4,r4,2		/* Update source pointer address */
	stb	r7,0(r6)	/* Store 2 bytes on dest */
	stb	r8,1(r6)
	addi	r6,r6,2		/* Update dest pointer address */
	bne	L(cachelinenotset_loop)
	blr


L(cachelineset):
	cmpd	cr5,r5,r10       /* Less than a cacheline to go? */

	neg     r7,r6           /* How far to next cacheline bdy? */

	addi    r6,r6,-8        /* prepare for stdu  */
	cmpdi   cr0,r9,128
	addi    r4,r4,-8        /* prepare for ldu  */


	ble+    cr5,L(lessthancacheline)

	beq-    cr0,L(big_lines) /* 128 byte line code */



	/* More than a cacheline left to go, and using 64 byte cachelines */

	clrldi  r7,r7,64-6      /* How far to next cacheline bdy? */

	cmpldi  cr6,r7,0        /* Are we on a cacheline bdy already? */

	/* Reduce total len by what it takes to get to the next cache line */
	subf    r5,r7,r5
	srdi    r7,r7,4         /* How many qws to get to the line bdy? */

	/* How many full cache lines to copy after getting to a line bdy? */
	srdi    r10,r5,6

	cmpldi  r10,0           /* If no full cache lines to copy ... */
	li      r11,0           /* number cachelines to copy with prefetch  */
	beq     L(nocacheprefetch)


	/* We are here because we have at least one full cache line to copy,
	   and therefore some pre-touching to do. */

	cmpldi  r10,PREFETCH_AHEAD
	li      r12,64+8        /* prefetch distance  */
	ble     L(lessthanmaxprefetch)

	/* We can only do so much pre-fetching.  R11 will have the count of
	   lines left to prefetch after the initial batch of prefetches
	   are executed. */

	subi    r11,r10,PREFETCH_AHEAD
	li      r10,PREFETCH_AHEAD

L(lessthanmaxprefetch):
	mtctr   r10

	/* At this point r10/ctr hold the number of lines to prefetch in this
	   initial batch, and r11 holds any remainder. */

L(prefetchSRC):
	dcbt    r12,r4
	addi    r12,r12,64
	bdnz    L(prefetchSRC)


	/* Prefetching is done, or was not needed.

	   cr6 - are we on a cacheline boundary already?
	   r7  - number of quadwords to the next cacheline boundary
	*/

L(nocacheprefetch):
	mtctr   r7

	cmpldi  cr1,r5,64   /* Less than a cache line to copy? */

	/* How many bytes are left after we copy whatever full
	   cache lines we can get? */
	clrldi  r5,r5,64-6

	beq     cr6,L(cachelinealigned)


	/* Copy quadwords up to the next cacheline boundary */

L(aligntocacheline):
	ld      r9,0x08(r4)
	ld      r7,0x10(r4)
	addi    r4,r4,0x10
	std     r9,0x08(r6)
	stdu    r7,0x10(r6)
	bdnz    L(aligntocacheline)


	.align 4
L(cachelinealigned):            /* copy while cache lines  */

	blt-    cr1,L(lessthancacheline) /* size <64  */

L(outerloop):
	cmpdi   r11,0
	mtctr   r11
	beq-    L(endloop)

	li      r11,64*ZERO_AHEAD +8    /* DCBZ dist  */

	.align  4
	/* Copy whole cachelines, optimized by prefetching SRC cacheline  */
L(loop):                        /* Copy aligned body  */
	dcbt    r12,r4          /* PREFETCH SOURCE some cache lines ahead  */
	ld      r9, 0x08(r4)
	dcbz    r11,r6
	ld      r7, 0x10(r4)
	ld      r8, 0x18(r4)
	ld      r0, 0x20(r4)
	std     r9, 0x08(r6)
	std     r7, 0x10(r6)
	std     r8, 0x18(r6)
	std     r0, 0x20(r6)
	ld      r9, 0x28(r4)
	ld      r7, 0x30(r4)
	ld      r8, 0x38(r4)
	ld      r0, 0x40(r4)
	addi    r4, r4,0x40
	std     r9, 0x28(r6)
	std     r7, 0x30(r6)
	std     r8, 0x38(r6)
	stdu    r0, 0x40(r6)

	bdnz    L(loop)


L(endloop):
	cmpdi   r10,0
	beq-    L(endloop2)
	mtctr   r10

L(loop2):                       /* Copy aligned body  */
	ld      r9, 0x08(r4)
	ld      r7, 0x10(r4)
	ld      r8, 0x18(r4)
	ld      r0, 0x20(r4)
	std     r9, 0x08(r6)
	std     r7, 0x10(r6)
	std     r8, 0x18(r6)
	std     r0, 0x20(r6)
	ld      r9, 0x28(r4)
	ld      r7, 0x30(r4)
	ld      r8, 0x38(r4)
	ld      r0, 0x40(r4)
	addi    r4, r4,0x40
	std     r9, 0x28(r6)
	std     r7, 0x30(r6)
	std     r8, 0x38(r6)
	stdu    r0, 0x40(r6)

	bdnz    L(loop2)
L(endloop2):


	.align 4
L(lessthancacheline):           /* Was there less than cache to do ?  */
	cmpldi  cr0,r5,16
	srdi    r7,r5,4         /* divide size by 16  */
	blt-    L(do_lt16)
	mtctr   r7

L(copy_remaining):
	ld      r8,0x08(r4)
	ld      r7,0x10(r4)
	addi    r4,r4,0x10
	std     r8,0x08(r6)
	stdu    r7,0x10(r6)
	bdnz    L(copy_remaining)

L(do_lt16):                     /* less than 16 ?  */
	cmpldi  cr0,r5,0        /* copy remaining bytes (0-15)  */
	beqlr+                  /* no rest to copy  */
	addi    r4,r4,8
	addi    r6,r6,8

L(shortcopy):                   /* SIMPLE COPY to handle size =< 15 bytes  */
	mtcrf   0x01,r5
	sub     r7,r4,r6
	bf-     cr7*4+0,8f
	ldx     r0,r7,r6        /* copy 8 byte  */
	std     r0,0(r6)
	addi    r6,r6,8
8:
	bf      cr7*4+1,4f
	lwzx    r0,r7,r6        /* copy 4 byte  */
	stw     r0,0(r6)
	addi    r6,r6,4
4:
	bf      cr7*4+2,2f
	lhzx    r0,r7,r6        /* copy 2 byte  */
	sth     r0,0(r6)
	addi    r6,r6,2
2:
	bf      cr7*4+3,1f
	lbzx    r0,r7,r6        /* copy 1 byte  */
	stb     r0,0(r6)
1:
	blr





	/* Similar to above, but for use with 128 byte lines. */


L(big_lines):

	clrldi  r7,r7,64-7      /* How far to next cacheline bdy? */

	cmpldi  cr6,r7,0        /* Are we on a cacheline bdy already? */

	/* Reduce total len by what it takes to get to the next cache line */
	subf    r5,r7,r5
	srdi    r7,r7,4         /* How many qws to get to the line bdy? */

	/* How many full cache lines to copy after getting to a line bdy? */
	srdi    r10,r5,7

	cmpldi  r10,0           /* If no full cache lines to copy ... */
	li      r11,0           /* number cachelines to copy with prefetch  */
	beq     L(nocacheprefetch_128)


	/* We are here because we have at least one full cache line to copy,
	   and therefore some pre-touching to do. */

	cmpldi  r10,PREFETCH_AHEAD
	li      r12,128+8       /* prefetch distance  */
	ble     L(lessthanmaxprefetch_128)

	/* We can only do so much pre-fetching.  R11 will have the count of
	   lines left to prefetch after the initial batch of prefetches
	   are executed. */

	subi    r11,r10,PREFETCH_AHEAD
	li      r10,PREFETCH_AHEAD

L(lessthanmaxprefetch_128):
	mtctr   r10

	/* At this point r10/ctr hold the number of lines to prefetch in this
	   initial batch, and r11 holds any remainder. */

L(prefetchSRC_128):
	dcbt    r12,r4
	addi    r12,r12,128
	bdnz    L(prefetchSRC_128)


	/* Prefetching is done, or was not needed.

	   cr6 - are we on a cacheline boundary already?
	   r7  - number of quadwords to the next cacheline boundary
	*/

L(nocacheprefetch_128):
	mtctr   r7

	cmpldi  cr1,r5,128  /* Less than a cache line to copy? */

	/* How many bytes are left after we copy whatever full
	   cache lines we can get? */
	clrldi  r5,r5,64-7

	beq     cr6,L(cachelinealigned_128)


	/* Copy quadwords up to the next cacheline boundary */

L(aligntocacheline_128):
	ld      r9,0x08(r4)
	ld      r7,0x10(r4)
	addi    r4,r4,0x10
	std     r9,0x08(r6)
	stdu    r7,0x10(r6)
	bdnz    L(aligntocacheline_128)


L(cachelinealigned_128):        /* copy while cache lines  */

	blt-    cr1,L(lessthancacheline) /* size <128  */

L(outerloop_128):
	cmpdi   r11,0
	mtctr   r11
	beq-    L(endloop_128)

	li      r11,128*ZERO_AHEAD +8    /* DCBZ dist  */

	.align  4
	/* Copy whole cachelines, optimized by prefetching SRC cacheline  */
L(loop_128):                    /* Copy aligned body  */
	dcbt    r12,r4          /* PREFETCH SOURCE some cache lines ahead  */
	ld      r9, 0x08(r4)
	dcbz    r11,r6
	ld      r7, 0x10(r4)
	ld      r8, 0x18(r4)
	ld      r0, 0x20(r4)
	std     r9, 0x08(r6)
	std     r7, 0x10(r6)
	std     r8, 0x18(r6)
	std     r0, 0x20(r6)
	ld      r9, 0x28(r4)
	ld      r7, 0x30(r4)
	ld      r8, 0x38(r4)
	ld      r0, 0x40(r4)
	std     r9, 0x28(r6)
	std     r7, 0x30(r6)
	std     r8, 0x38(r6)
	std     r0, 0x40(r6)
	ld      r9, 0x48(r4)
	ld      r7, 0x50(r4)
	ld      r8, 0x58(r4)
	ld      r0, 0x60(r4)
	std     r9, 0x48(r6)
	std     r7, 0x50(r6)
	std     r8, 0x58(r6)
	std     r0, 0x60(r6)
	ld      r9, 0x68(r4)
	ld      r7, 0x70(r4)
	ld      r8, 0x78(r4)
	ld      r0, 0x80(r4)
	addi    r4, r4,0x80
	std     r9, 0x68(r6)
	std     r7, 0x70(r6)
	std     r8, 0x78(r6)
	stdu    r0, 0x80(r6)

	bdnz    L(loop_128)


L(endloop_128):
	cmpdi   r10,0
	beq-    L(endloop2_128)
	mtctr   r10

L(loop2_128):                       /* Copy aligned body  */
	ld      r9, 0x08(r4)
	ld      r7, 0x10(r4)
	ld      r8, 0x18(r4)
	ld      r0, 0x20(r4)
	std     r9, 0x08(r6)
	std     r7, 0x10(r6)
	std     r8, 0x18(r6)
	std     r0, 0x20(r6)
	ld      r9, 0x28(r4)
	ld      r7, 0x30(r4)
	ld      r8, 0x38(r4)
	ld      r0, 0x40(r4)
	std     r9, 0x28(r6)
	std     r7, 0x30(r6)
	std     r8, 0x38(r6)
	std     r0, 0x40(r6)
	ld      r9, 0x48(r4)
	ld      r7, 0x50(r4)
	ld      r8, 0x58(r4)
	ld      r0, 0x60(r4)
	std     r9, 0x48(r6)
	std     r7, 0x50(r6)
	std     r8, 0x58(r6)
	std     r0, 0x60(r6)
	ld      r9, 0x68(r4)
	ld      r7, 0x70(r4)
	ld      r8, 0x78(r4)
	ld      r0, 0x80(r4)
	addi    r4, r4,0x80
	std     r9, 0x68(r6)
	std     r7, 0x70(r6)
	std     r8, 0x78(r6)
	stdu    r0, 0x80(r6)

	bdnz    L(loop2_128)
L(endloop2_128):

	b       L(lessthancacheline)


END_GEN_TB (MEMCPY,TB_TOCLESS)
libc_hidden_builtin_def (memcpy)