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
|
/* Optimized 64-bit memset implementation for POWER6.
Copyright (C) 1997-2020 Free Software Foundation, Inc.
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>
/* void * [r3] memset (void *s [r3], int c [r4], size_t n [r5]));
Returns 's'.
The memset is done in three sizes: byte (8 bits), word (32 bits),
cache line (256 bits). There is a special case for setting cache lines
to 0, to take advantage of the dcbz instruction. */
#ifndef MEMSET
# define MEMSET memset
#endif
.machine power6
ENTRY_TOCLESS (MEMSET, 7)
CALL_MCOUNT 3
#define rTMP r0
#define rRTN r3 /* Initial value of 1st argument. */
#define rMEMP0 r3 /* Original value of 1st arg. */
#define rCHR r4 /* Char to set in each byte. */
#define rLEN r5 /* Length of region to set. */
#define rMEMP r6 /* Address at which we are storing. */
#define rALIGN r7 /* Number of bytes we are setting now (when aligning). */
#define rMEMP2 r8
#define rMEMP3 r9 /* Alt mem pointer. */
L(_memset):
/* Take care of case for size <= 4. */
cmpldi cr1, rLEN, 8
andi. rALIGN, rMEMP0, 7
mr rMEMP, rMEMP0
ble cr1, L(small)
/* Align to doubleword boundary. */
cmpldi cr5, rLEN, 31
insrdi rCHR, rCHR, 8, 48 /* Replicate byte to halfword. */
beq+ L(aligned2)
mtcrf 0x01, rMEMP0
subfic rALIGN, rALIGN, 8
cror 28,30,31 /* Detect odd word aligned. */
add rMEMP, rMEMP, rALIGN
sub rLEN, rLEN, rALIGN
insrdi rCHR, rCHR, 16, 32 /* Replicate halfword to word. */
bt 29, L(g4)
/* Process the even word of doubleword. */
bf+ 31, L(g2)
stb rCHR, 0(rMEMP0)
bt 30, L(g4x)
L(g2):
sth rCHR, -6(rMEMP)
L(g4x):
stw rCHR, -4(rMEMP)
b L(aligned)
/* Process the odd word of doubleword. */
L(g4):
bf 28, L(g4x) /* If false, word aligned on odd word. */
bf+ 31, L(g0)
stb rCHR, 0(rMEMP0)
bt 30, L(aligned)
L(g0):
sth rCHR, -2(rMEMP)
/* Handle the case of size < 31. */
L(aligned2):
insrdi rCHR, rCHR, 16, 32 /* Replicate halfword to word. */
L(aligned):
mtcrf 0x01, rLEN
ble cr5, L(medium)
/* Align to 32-byte boundary. */
andi. rALIGN, rMEMP, 0x18
subfic rALIGN, rALIGN, 0x20
insrdi rCHR, rCHR, 32, 0 /* Replicate word to double word. */
beq L(caligned)
mtcrf 0x01, rALIGN
add rMEMP, rMEMP, rALIGN
sub rLEN, rLEN, rALIGN
cmplwi cr1, rALIGN, 0x10
mr rMEMP2, rMEMP
bf 28, L(a1)
stdu rCHR, -8(rMEMP2)
L(a1): blt cr1, L(a2)
std rCHR, -8(rMEMP2)
stdu rCHR, -16(rMEMP2)
L(a2):
/* Now aligned to a 32 byte boundary. */
.align 4
L(caligned):
cmpldi cr1, rCHR, 0
clrrdi. rALIGN, rLEN, 5
mtcrf 0x01, rLEN
beq cr1, L(zloopstart) /* Special case for clearing memory using dcbz. */
beq L(medium) /* We may not actually get to do a full line. */
.align 4
/* Storing a non-zero "c" value. We are aligned at a sector (32-byte)
boundary may not be at cache line (128-byte) boundary. */
L(nzloopstart):
/* memset in 32-byte chunks until we get to a cache line boundary.
If rLEN is less than the distance to the next cache-line boundary use
cacheAligned1 code to finish the tail. */
cmpldi cr1,rLEN,128
andi. rTMP,rMEMP,127
blt cr1,L(cacheAligned1)
addi rMEMP3,rMEMP,32
beq L(nzCacheAligned)
addi rLEN,rLEN,-32
std rCHR,0(rMEMP)
std rCHR,8(rMEMP)
std rCHR,16(rMEMP)
addi rMEMP,rMEMP,32
andi. rTMP,rMEMP3,127
std rCHR,-8(rMEMP3)
beq L(nzCacheAligned)
addi rLEN,rLEN,-32
std rCHR,0(rMEMP3)
addi rMEMP,rMEMP,32
std rCHR,8(rMEMP3)
andi. rTMP,rMEMP,127
std rCHR,16(rMEMP3)
std rCHR,24(rMEMP3)
beq L(nzCacheAligned)
addi rLEN,rLEN,-32
std rCHR,32(rMEMP3)
addi rMEMP,rMEMP,32
cmpldi cr1,rLEN,128
std rCHR,40(rMEMP3)
cmpldi cr6,rLEN,256
li rMEMP2,128
std rCHR,48(rMEMP3)
std rCHR,56(rMEMP3)
blt cr1,L(cacheAligned1)
b L(nzCacheAligned128)
/* Now we are aligned to the cache line and can use dcbtst. */
.align 4
L(nzCacheAligned):
cmpldi cr1,rLEN,128
blt cr1,L(cacheAligned1)
b L(nzCacheAligned128)
.align 5
L(nzCacheAligned128):
cmpldi cr1,rLEN,256
addi rMEMP3,rMEMP,64
std rCHR,0(rMEMP)
std rCHR,8(rMEMP)
std rCHR,16(rMEMP)
std rCHR,24(rMEMP)
std rCHR,32(rMEMP)
std rCHR,40(rMEMP)
std rCHR,48(rMEMP)
std rCHR,56(rMEMP)
addi rMEMP,rMEMP3,64
addi rLEN,rLEN,-128
std rCHR,0(rMEMP3)
std rCHR,8(rMEMP3)
std rCHR,16(rMEMP3)
std rCHR,24(rMEMP3)
std rCHR,32(rMEMP3)
std rCHR,40(rMEMP3)
std rCHR,48(rMEMP3)
std rCHR,56(rMEMP3)
bge cr1,L(nzCacheAligned128)
dcbtst 0,rMEMP
b L(cacheAligned1)
.align 5
/* Storing a zero "c" value. We are aligned at a sector (32-byte)
boundary but may not be at cache line (128-byte) boundary. If the
remaining length spans a full cache line we can use the Data cache
block zero instruction. */
L(zloopstart):
/* memset in 32-byte chunks until we get to a cache line boundary.
If rLEN is less than the distance to the next cache-line boundary use
cacheAligned1 code to finish the tail. */
cmpldi cr1,rLEN,128
beq L(medium)
L(getCacheAligned):
andi. rTMP,rMEMP,127
nop
blt cr1,L(cacheAligned1)
addi rMEMP3,rMEMP,32
beq L(cacheAligned)
addi rLEN,rLEN,-32
std rCHR,0(rMEMP)
std rCHR,8(rMEMP)
std rCHR,16(rMEMP)
addi rMEMP,rMEMP,32
andi. rTMP,rMEMP3,127
std rCHR,-8(rMEMP3)
L(getCacheAligned2):
beq L(cacheAligned)
addi rLEN,rLEN,-32
std rCHR,0(rMEMP3)
std rCHR,8(rMEMP3)
addi rMEMP,rMEMP,32
andi. rTMP,rMEMP,127
std rCHR,16(rMEMP3)
std rCHR,24(rMEMP3)
L(getCacheAligned3):
beq L(cacheAligned)
addi rLEN,rLEN,-32
std rCHR,32(rMEMP3)
addi rMEMP,rMEMP,32
cmpldi cr1,rLEN,128
std rCHR,40(rMEMP3)
cmpldi cr6,rLEN,256
li rMEMP2,128
std rCHR,48(rMEMP3)
std rCHR,56(rMEMP3)
blt cr1,L(cacheAligned1)
blt cr6,L(cacheAligned128)
b L(cacheAlignedx)
/* Now we are aligned to the cache line and can use dcbz. */
.align 5
L(cacheAligned):
cmpldi cr1,rLEN,128
cmpldi cr6,rLEN,256
blt cr1,L(cacheAligned1)
li rMEMP2,128
L(cacheAlignedx):
cmpldi cr5,rLEN,640
blt cr6,L(cacheAligned128)
bgt cr5,L(cacheAligned512)
cmpldi cr6,rLEN,512
dcbz 0,rMEMP
cmpldi cr1,rLEN,384
dcbz rMEMP2,rMEMP
addi rMEMP,rMEMP,256
addi rLEN,rLEN,-256
blt cr1,L(cacheAligned1)
blt cr6,L(cacheAligned128)
b L(cacheAligned256)
.align 5
/* A simple loop for the longer (>640 bytes) lengths. This form limits
the branch miss-predicted to exactly 1 at loop exit.*/
L(cacheAligned512):
cmpldi cr1,rLEN,128
blt cr1,L(cacheAligned1)
dcbz 0,rMEMP
addi rLEN,rLEN,-128
addi rMEMP,rMEMP,128
b L(cacheAligned512)
.align 5
L(cacheAligned256):
cmpldi cr6,rLEN,512
dcbz 0,rMEMP
cmpldi cr1,rLEN,384
dcbz rMEMP2,rMEMP
addi rMEMP,rMEMP,256
addi rLEN,rLEN,-256
bge cr6,L(cacheAligned256)
blt cr1,L(cacheAligned1)
.align 4
L(cacheAligned128):
dcbz 0,rMEMP
addi rMEMP,rMEMP,128
addi rLEN,rLEN,-128
nop
L(cacheAligned1):
cmpldi cr1,rLEN,32
blt cr1,L(handletail32)
addi rMEMP3,rMEMP,32
addi rLEN,rLEN,-32
std rCHR,0(rMEMP)
std rCHR,8(rMEMP)
std rCHR,16(rMEMP)
addi rMEMP,rMEMP,32
cmpldi cr1,rLEN,32
std rCHR,-8(rMEMP3)
L(cacheAligned2):
blt cr1,L(handletail32)
addi rLEN,rLEN,-32
std rCHR,0(rMEMP3)
std rCHR,8(rMEMP3)
addi rMEMP,rMEMP,32
cmpldi cr1,rLEN,32
std rCHR,16(rMEMP3)
std rCHR,24(rMEMP3)
nop
L(cacheAligned3):
blt cr1,L(handletail32)
addi rMEMP,rMEMP,32
addi rLEN,rLEN,-32
std rCHR,32(rMEMP3)
std rCHR,40(rMEMP3)
std rCHR,48(rMEMP3)
std rCHR,56(rMEMP3)
/* We are here because the length or remainder (rLEN) is less than the
cache line/sector size and does not justify aggressive loop unrolling.
So set up the preconditions for L(medium) and go there. */
.align 3
L(handletail32):
cmpldi cr1,rLEN,0
beqlr cr1
b L(medium)
.align 5
L(small):
/* Memset of 8 bytes or less. */
cmpldi cr6, rLEN, 4
cmpldi cr5, rLEN, 1
ble cr6,L(le4)
subi rLEN, rLEN, 4
stb rCHR,0(rMEMP)
stb rCHR,1(rMEMP)
stb rCHR,2(rMEMP)
stb rCHR,3(rMEMP)
addi rMEMP,rMEMP, 4
cmpldi cr5, rLEN, 1
L(le4):
cmpldi cr1, rLEN, 3
bltlr cr5
stb rCHR, 0(rMEMP)
beqlr cr5
stb rCHR, 1(rMEMP)
bltlr cr1
stb rCHR, 2(rMEMP)
beqlr cr1
stb rCHR, 3(rMEMP)
blr
/* Memset of 0-31 bytes. */
.align 5
L(medium):
insrdi rCHR, rCHR, 32, 0 /* Replicate word to double word. */
cmpldi cr1, rLEN, 16
L(medium_tail2):
add rMEMP, rMEMP, rLEN
L(medium_tail):
bt- 31, L(medium_31t)
bt- 30, L(medium_30t)
L(medium_30f):
bt 29, L(medium_29t)
L(medium_29f):
bge cr1, L(medium_27t)
bflr 28
std rCHR, -8(rMEMP)
blr
L(medium_31t):
stbu rCHR, -1(rMEMP)
bf- 30, L(medium_30f)
L(medium_30t):
sthu rCHR, -2(rMEMP)
bf- 29, L(medium_29f)
L(medium_29t):
stwu rCHR, -4(rMEMP)
blt cr1, L(medium_27f)
L(medium_27t):
std rCHR, -8(rMEMP)
stdu rCHR, -16(rMEMP)
L(medium_27f):
bflr 28
L(medium_28t):
std rCHR, -8(rMEMP)
blr
END_GEN_TB (MEMSET,TB_TOCLESS)
libc_hidden_builtin_def (memset)
/* Copied from bzero.S to prevent the linker from inserting a stub
between bzero and memset. */
ENTRY_TOCLESS (__bzero)
CALL_MCOUNT 3
mr r5,r4
li r4,0
b L(_memset)
END (__bzero)
#ifndef __bzero
weak_alias (__bzero, bzero)
#endif
|
