summaryrefslogtreecommitdiff
path: root/sysdeps/powerpc/powerpc32/power7/memset.S
blob: 9cee5f1677d9a63ce0a266d1dda0c2888f47e1cf (plain)
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
/* Optimized memset implementation for PowerPC32/POWER7.
   Copyright (C) 2010-2016 Free Software Foundation, Inc.
   Contributed by Luis Machado <luisgpm@br.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
   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>

/* __ptr_t [r3] memset (__ptr_t s [r3], int c [r4], size_t n [r5]));
   Returns 's'.  */

	.machine  power7
EALIGN (memset, 5, 0)
	CALL_MCOUNT

	.align	4
L(_memset):
	cmplwi	cr7,5,31
	cmplwi	cr6,5,8
	mr	10,3		/* Save original argument for later.  */
	mr	7,1		/* Save original r1 for later.  */
	cfi_offset(31,-8)

	/* Replicate byte to word.  */
	insrwi	4,4,8,16
	insrwi	4,4,16,0

	ble	cr6,L(small)	/* If length <= 8, use short copy code.  */

	neg	0,3
	ble	cr7,L(medium)	/* If length < 32, use medium copy code.  */

	/* Save our word twice to create a doubleword that we will later
	   copy to a FPR.  */
	stwu	1,-32(1)
	andi.	11,10,7		/* Check alignment of DST.  */
	mr	12,5
	stw	4,24(1)
	stw	4,28(1)
	beq	L(big_aligned)

	clrlwi	0,0,29
	mtocrf	0x01,0
	subf	5,0,5

	/* Get DST aligned to 8 bytes.  */
1:	bf	31,2f

	stb	4,0(10)
	addi	10,10,1
2:	bf	30,4f

	sth	4,0(10)
	addi	10,10,2
4:	bf	29,L(big_aligned)

	stw	4,0(10)
	addi	10,10,4

	.align	4
L(big_aligned):
	cmplwi	cr5,5,255
	li	0,32
	cmplwi	cr1,5,160
	dcbtst	0,10
	cmplwi	cr6,4,0
	srwi	9,5,3		/* Number of full doublewords remaining.  */
	crand	27,26,21
	mtocrf	0x01,9
	bt	27,L(huge)

	/* From this point on, we'll copy 32+ bytes and the value
	   isn't 0 (so we can't use dcbz).  */

	srwi	8,5,5
	clrlwi	11,5,29
	cmplwi	cr6,11,0
	cmplwi	cr1,9,4
	mtctr	8

	/* Copy 1~3 doublewords so the main loop starts
	at a multiple of 32 bytes.  */

	bf	30,1f

	stw	4,0(10)
	stw	4,4(10)
	stw	4,8(10)
	stw	4,12(10)
	addi	10,10,16
	bf	31,L(big_loop)

	stw	4,0(10)
	stw	4,4(10)
	addi	10,10,8
	mr	12,10
	blt	cr1,L(tail_bytes)

	b	L(big_loop)

	.align	4
1:	/* Copy 1 doubleword.  */
	bf	31,L(big_loop)

	stw	4,0(10)
	stw	4,4(10)
	addi	10,10,8

	/* First use a 32-bytes loop with stw's to try and avoid the LHS due
	   to the lfd we will do next.  Also, ping-pong through r10 and r12
	   to avoid AGEN delays.  */
	.align	4
L(big_loop):
	addi	12,10,32
	stw	4,0(10)
	stw	4,4(10)
	stw	4,8(10)
	stw	4,12(10)
	stw	4,16(10)
	stw	4,20(10)
	stw	4,24(10)
	stw	4,28(10)
	bdz	L(tail_bytes)

	addi	10,10,64
	stw	4,0(12)
	stw	4,4(12)
	stw	4,8(12)
	stw	4,12(12)
	stw	4,16(12)
	stw	4,20(12)
	stw	4,24(12)
	stw	4,28(12)
	bdnz	L(big_loop_fast_setup)

	mr	12,10
	b	L(tail_bytes)

	/* Now that we're probably past the LHS window, use the VSX to
	   speed up the loop.  */
L(big_loop_fast_setup):
	li	11,24
	li	6,16
	lxvdsx	4,1,11

	.align	4
L(big_loop_fast):
	addi	12,10,32
	stxvd2x	4,0,10
	stxvd2x	4,10,6
	bdz	L(tail_bytes)

	addi	10,10,64
	stxvd2x	4,0,12
	stxvd2x	4,12,6
	bdnz	L(big_loop_fast)

	mr	12,10

	.align	4
L(tail_bytes):

	/* Check for tail bytes.  */
	mr	1,7		/* Restore r1.  */
	beqlr	cr6

	clrlwi	0,5,29
	mtocrf	0x01,0

	/*  At this point we have a tail of 0-7 bytes and we know that the
	destination is doubleword-aligned.  */
4:	/* Copy 4 bytes.  */
	bf	29,2f

	stw	4,0(12)
	addi	12,12,4
2:	/* Copy 2 bytes.  */
	bf	30,1f

	sth	4,0(12)
	addi	12,12,2
1:	/* Copy 1 byte.  */
	bflr	31

	stb	4,0(12)
	blr


	/* Special case when value is 0 and we have a long length to deal
	   with.  Use dcbz to zero out 128-bytes at a time.  Before using
	   dcbz though, we need to get the destination 128-bytes aligned.  */
	.align	4
L(huge):
	lfd	4,24(1)
	andi.	11,10,127
	neg	0,10
	beq	L(huge_aligned)

	clrlwi	0,0,25
	subf	5,0,5
	srwi	0,0,3
	mtocrf  0x01,0

	/* Get DST aligned to 128 bytes.  */
8:	bf	28,4f

	stfd	4,0(10)
	stfd	4,8(10)
	stfd	4,16(10)
	stfd	4,24(10)
	stfd	4,32(10)
	stfd	4,40(10)
	stfd	4,48(10)
	stfd	4,56(10)
	addi	10,10,64
	.align	4
4:	bf	29,2f

	stfd	4,0(10)
	stfd	4,8(10)
	stfd	4,16(10)
	stfd	4,24(10)
	addi	10,10,32
	.align	4
2:	bf	30,1f

	stfd	4,0(10)
	stfd	4,8(10)
	addi	10,10,16
	.align	4
1:	bf	31,L(huge_aligned)

	stfd	4,0(10)
	addi	10,10,8

L(huge_aligned):
	srwi	8,5,7
	clrlwi	11,5,25
	cmplwi	cr6,11,0
	mtctr	8

	/* Copies 128-bytes at a time.  */
	.align	4
L(huge_loop):
	dcbz	0,10
	addi	10,10,128
	bdnz	L(huge_loop)

	/* We have a tail of 0~127 bytes to handle.  */
	mr	1,7		/* Restore r1.  */
	beqlr	cr6

	subf	9,3,10
	subf	5,9,12
	srwi	8,5,3
	cmplwi	cr6,8,0
	mtocrf	0x01,8

	/* We have a tail o 1~127 bytes. Copy up to 15 doublewords for
	speed.  We'll handle the resulting tail bytes later.  */
	beq	cr6,L(tail)

8:	bf	28,4f

	stfd	4,0(10)
	stfd	4,8(10)
	stfd	4,16(10)
	stfd	4,24(10)
	stfd	4,32(10)
	stfd	4,40(10)
	stfd	4,48(10)
	stfd	4,56(10)
	addi	10,10,64
	.align	4
4:	bf	29,2f

	stfd	4,0(10)
	stfd	4,8(10)
	stfd	4,16(10)
	stfd	4,24(10)
	addi	10,10,32
	.align	4
2:	bf	30,1f

	stfd	4,0(10)
	stfd	4,8(10)
	addi	10,10,16
	.align	4
1:	bf	31,L(tail)

	stfd	4,0(10)
	addi	10,10,8

	/* Handle the rest of the tail bytes here.  */
L(tail):
	mtocrf	0x01,5

	.align	4
4:	bf	29,2f

	stw	4,0(10)
	addi	10,10,4
	.align	4
2:	bf	30,1f

	sth	4,0(10)
	addi	10,10,2
	.align	4
1:	bflr	31

	stb	4,0(10)
	blr


	/* Expanded tree to copy tail bytes without increments.  */
	.align	4
L(copy_tail):
	bf	29,L(FXX)

	stw	4,0(10)
	bf	30,L(TFX)

	sth	4,4(10)
	bflr	31

	stb	4,6(10)
	blr

	.align	4
L(FXX):	bf	30,L(FFX)

	sth	4,0(10)
	bflr	31

	stb	4,2(10)
	blr

	.align	4
L(TFX):	bflr	31

	stb	4,4(10)
	blr

	.align	4
L(FFX):	bflr	31

	stb	4,0(10)
	blr

	/* Handle copies of 9~31 bytes.  */
	.align	4
L(medium):
	/* At least 9 bytes to go.  */
	andi.	11,10,3
	clrlwi	0,0,30
	beq	L(medium_aligned)

	/* Force 4-bytes alignment for DST.  */
	mtocrf	0x01,0
	subf	5,0,5
1:	/* Copy 1 byte.  */
	bf	31,2f

	stb	4,0(10)
	addi	10,10,1
2:	/* Copy 2 bytes.  */
	bf	30,L(medium_aligned)

	sth	4,0(10)
	addi	10,10,2

	.align	4
L(medium_aligned):
	/* At least 6 bytes to go, and DST is word-aligned.  */
	cmplwi	cr1,5,16
	mtocrf	0x01,5
	blt	cr1,8f

	/* Copy 16 bytes.  */
	stw	4,0(10)
	stw	4,4(10)
	stw	4,8(10)
	stw	4,12(10)
	addi	10,10,16
8:	/* Copy 8 bytes.  */
	bf	28,4f

	stw	4,0(10)
	stw	4,4(10)
	addi	10,10,8
4:	/* Copy 4 bytes.  */
	bf	29,2f

	stw	4,0(10)
	addi	10,10,4
2:	/* Copy 2-3 bytes.  */
	bf	30,1f

	sth	4,0(10)
	addi	10,10,2
1:	/* Copy 1 byte.  */
	bflr	31

	stb	4,0(10)
	blr

	/* Handles copies of 0~8 bytes.  */
	.align	4
L(small):
	mtocrf	0x01,5
	bne	cr6,L(copy_tail)

	stw	4,0(10)
	stw	4,4(10)
	blr

END (memset)
libc_hidden_builtin_def (memset)