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04067002 | 1 | /* Optimized memcpy implementation for PowerPC64. |
bfff8b1b | 2 | Copyright (C) 2003-2017 Free Software Foundation, Inc. |
04067002 UD |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
04067002 UD |
18 | |
19 | #include <sysdep.h> | |
04067002 | 20 | |
f17a4233 | 21 | /* void * [r3] memcpy (void *dst [r3], void *src [r4], size_t len [r5]); |
04067002 UD |
22 | Returns 'dst'. |
23 | ||
9c84384c JM |
24 | Memcpy handles short copies (< 32-bytes) using a binary move blocks |
25 | (no loops) of lwz/stw. The tail (remaining 1-3) bytes is handled | |
26 | with the appropriate combination of byte and halfword load/stores. | |
27 | There is minimal effort to optimize the alignment of short moves. | |
04067002 | 28 | The 64-bit implementations of POWER3 and POWER4 do a reasonable job |
2ccdea26 | 29 | of handling unaligned load/stores that do not cross 32-byte boundaries. |
04067002 UD |
30 | |
31 | Longer moves (>= 32-bytes) justify the effort to get at least the | |
32 | destination doubleword (8-byte) aligned. Further optimization is | |
2ccdea26 | 33 | possible when both source and destination are doubleword aligned. |
04067002 UD |
34 | Each case has a optimized unrolled loop. */ |
35 | ||
72fd128a WSM |
36 | #ifndef MEMCPY |
37 | # define MEMCPY memcpy | |
38 | #endif | |
a88f47a7 | 39 | .machine power4 |
d5b41185 | 40 | ENTRY_TOCLESS (MEMCPY, 5) |
04067002 UD |
41 | CALL_MCOUNT 3 |
42 | ||
43 | cmpldi cr1,5,31 | |
44 | neg 0,3 | |
45 | std 3,-16(1) | |
46 | std 31,-8(1) | |
47 | cfi_offset(31,-8) | |
2ccdea26 | 48 | andi. 11,3,7 /* check alignment of dst. */ |
04067002 | 49 | clrldi 0,0,61 /* Number of bytes until the 1st doubleword of dst. */ |
2ccdea26 | 50 | clrldi 10,4,61 /* check alignment of src. */ |
04067002 UD |
51 | cmpldi cr6,5,8 |
52 | ble- cr1,.L2 /* If move < 32 bytes use short move code. */ | |
9c84384c | 53 | cmpld cr6,10,11 |
04067002 UD |
54 | mr 12,4 |
55 | srdi 9,5,3 /* Number of full double words remaining. */ | |
56 | mtcrf 0x01,0 | |
57 | mr 31,5 | |
58 | beq .L0 | |
9c84384c | 59 | |
04067002 | 60 | subf 31,0,5 |
2ccdea26 | 61 | /* Move 0-7 bytes as needed to get the destination doubleword aligned. */ |
04067002 UD |
62 | 1: bf 31,2f |
63 | lbz 6,0(12) | |
64 | addi 12,12,1 | |
65 | stb 6,0(3) | |
66 | addi 3,3,1 | |
67 | 2: bf 30,4f | |
68 | lhz 6,0(12) | |
69 | addi 12,12,2 | |
70 | sth 6,0(3) | |
71 | addi 3,3,2 | |
72 | 4: bf 29,0f | |
73 | lwz 6,0(12) | |
74 | addi 12,12,4 | |
75 | stw 6,0(3) | |
76 | addi 3,3,4 | |
77 | 0: | |
2ccdea26 | 78 | clrldi 10,12,61 /* check alignment of src again. */ |
04067002 | 79 | srdi 9,31,3 /* Number of full double words remaining. */ |
9c84384c | 80 | |
2ccdea26 | 81 | /* Copy doublewords from source to destination, assuming the |
04067002 UD |
82 | destination is aligned on a doubleword boundary. |
83 | ||
84 | At this point we know there are at least 25 bytes left (32-7) to copy. | |
9c84384c | 85 | The next step is to determine if the source is also doubleword aligned. |
04067002 UD |
86 | If not branch to the unaligned move code at .L6. which uses |
87 | a load, shift, store strategy. | |
9c84384c | 88 | |
04067002 UD |
89 | Otherwise source and destination are doubleword aligned, and we can |
90 | the optimized doubleword copy loop. */ | |
91 | .L0: | |
92 | clrldi 11,31,61 | |
93 | mtcrf 0x01,9 | |
94 | cmpldi cr1,11,0 | |
95 | bne- cr6,.L6 /* If source is not DW aligned. */ | |
96 | ||
97 | /* Move doublewords where destination and source are DW aligned. | |
98 | Use a unrolled loop to copy 4 doubleword (32-bytes) per iteration. | |
ded5b9b7 | 99 | If the copy is not an exact multiple of 32 bytes, 1-3 |
04067002 | 100 | doublewords are copied as needed to set up the main loop. After |
9c84384c | 101 | the main loop exits there may be a tail of 1-7 bytes. These byte are |
04067002 UD |
102 | copied a word/halfword/byte at a time as needed to preserve alignment. */ |
103 | ||
104 | srdi 8,31,5 | |
105 | cmpldi cr1,9,4 | |
106 | cmpldi cr6,11,0 | |
107 | mr 11,12 | |
9c84384c | 108 | |
04067002 UD |
109 | bf 30,1f |
110 | ld 6,0(12) | |
111 | ld 7,8(12) | |
112 | addi 11,12,16 | |
113 | mtctr 8 | |
114 | std 6,0(3) | |
115 | std 7,8(3) | |
116 | addi 10,3,16 | |
117 | bf 31,4f | |
118 | ld 0,16(12) | |
9c84384c | 119 | std 0,16(3) |
04067002 UD |
120 | blt cr1,3f |
121 | addi 11,12,24 | |
122 | addi 10,3,24 | |
123 | b 4f | |
124 | .align 4 | |
125 | 1: | |
126 | mr 10,3 | |
127 | mtctr 8 | |
128 | bf 31,4f | |
129 | ld 6,0(12) | |
130 | addi 11,12,8 | |
131 | std 6,0(3) | |
132 | addi 10,3,8 | |
9c84384c | 133 | |
04067002 UD |
134 | .align 4 |
135 | 4: | |
136 | ld 6,0(11) | |
137 | ld 7,8(11) | |
138 | ld 8,16(11) | |
139 | ld 0,24(11) | |
140 | addi 11,11,32 | |
141 | 2: | |
142 | std 6,0(10) | |
143 | std 7,8(10) | |
144 | std 8,16(10) | |
145 | std 0,24(10) | |
146 | addi 10,10,32 | |
147 | bdnz 4b | |
9c84384c | 148 | 3: |
04067002 UD |
149 | |
150 | rldicr 0,31,0,60 | |
151 | mtcrf 0x01,31 | |
152 | beq cr6,0f | |
153 | .L9: | |
154 | add 3,3,0 | |
155 | add 12,12,0 | |
9c84384c | 156 | |
04067002 | 157 | /* At this point we have a tail of 0-7 bytes and we know that the |
2ccdea26 | 158 | destination is double word aligned. */ |
04067002 UD |
159 | 4: bf 29,2f |
160 | lwz 6,0(12) | |
161 | addi 12,12,4 | |
162 | stw 6,0(3) | |
163 | addi 3,3,4 | |
164 | 2: bf 30,1f | |
165 | lhz 6,0(12) | |
166 | addi 12,12,2 | |
167 | sth 6,0(3) | |
168 | addi 3,3,2 | |
169 | 1: bf 31,0f | |
170 | lbz 6,0(12) | |
171 | stb 6,0(3) | |
172 | 0: | |
173 | /* Return original dst pointer. */ | |
174 | ld 31,-8(1) | |
175 | ld 3,-16(1) | |
176 | blr | |
9c84384c JM |
177 | |
178 | /* Copy up to 31 bytes. This divided into two cases 0-8 bytes and 9-31 | |
179 | bytes. Each case is handled without loops, using binary (1,2,4,8) | |
180 | tests. | |
181 | ||
04067002 | 182 | In the short (0-8 byte) case no attempt is made to force alignment |
9c84384c JM |
183 | of either source or destination. The hardware will handle the |
184 | unaligned load/stores with small delays for crossing 32- 64-byte, and | |
04067002 | 185 | 4096-byte boundaries. Since these short moves are unlikely to be |
9c84384c | 186 | unaligned or cross these boundaries, the overhead to force |
04067002 | 187 | alignment is not justified. |
9c84384c | 188 | |
04067002 UD |
189 | The longer (9-31 byte) move is more likely to cross 32- or 64-byte |
190 | boundaries. Since only loads are sensitive to the 32-/64-byte | |
9c84384c | 191 | boundaries it is more important to align the source then the |
04067002 | 192 | destination. If the source is not already word aligned, we first |
9c84384c JM |
193 | move 1-3 bytes as needed. Since we are only word aligned we don't |
194 | use double word load/stores to insure that all loads are aligned. | |
04067002 UD |
195 | While the destination and stores may still be unaligned, this |
196 | is only an issue for page (4096 byte boundary) crossing, which | |
197 | should be rare for these short moves. The hardware handles this | |
9c84384c JM |
198 | case automatically with a small delay. */ |
199 | ||
04067002 UD |
200 | .align 4 |
201 | .L2: | |
202 | mtcrf 0x01,5 | |
203 | neg 8,4 | |
204 | clrrdi 11,4,2 | |
205 | andi. 0,8,3 | |
206 | ble cr6,.LE8 /* Handle moves of 0-8 bytes. */ | |
207 | /* At least 9 bytes left. Get the source word aligned. */ | |
208 | cmpldi cr1,5,16 | |
209 | mr 10,5 | |
210 | mr 12,4 | |
211 | cmpldi cr6,0,2 | |
212 | beq .L3 /* If the source is already word aligned skip this. */ | |
213 | /* Copy 1-3 bytes to get source address word aligned. */ | |
214 | lwz 6,0(11) | |
215 | subf 10,0,5 | |
216 | add 12,4,0 | |
217 | blt cr6,5f | |
218 | srdi 7,6,16 | |
219 | bgt cr6,3f | |
759cfef3 AM |
220 | #ifdef __LITTLE_ENDIAN__ |
221 | sth 7,0(3) | |
222 | #else | |
04067002 | 223 | sth 6,0(3) |
759cfef3 | 224 | #endif |
04067002 UD |
225 | b 7f |
226 | .align 4 | |
227 | 3: | |
759cfef3 AM |
228 | #ifdef __LITTLE_ENDIAN__ |
229 | rotlwi 6,6,24 | |
230 | stb 6,0(3) | |
231 | sth 7,1(3) | |
232 | #else | |
04067002 UD |
233 | stb 7,0(3) |
234 | sth 6,1(3) | |
759cfef3 | 235 | #endif |
04067002 UD |
236 | b 7f |
237 | .align 4 | |
238 | 5: | |
759cfef3 AM |
239 | #ifdef __LITTLE_ENDIAN__ |
240 | rotlwi 6,6,8 | |
241 | #endif | |
04067002 UD |
242 | stb 6,0(3) |
243 | 7: | |
244 | cmpldi cr1,10,16 | |
245 | add 3,3,0 | |
246 | mtcrf 0x01,10 | |
247 | .align 4 | |
248 | .L3: | |
249 | /* At least 6 bytes left and the source is word aligned. */ | |
250 | blt cr1,8f | |
251 | 16: /* Move 16 bytes. */ | |
252 | lwz 6,0(12) | |
253 | lwz 7,4(12) | |
254 | stw 6,0(3) | |
255 | lwz 6,8(12) | |
256 | stw 7,4(3) | |
257 | lwz 7,12(12) | |
258 | addi 12,12,16 | |
259 | stw 6,8(3) | |
260 | stw 7,12(3) | |
261 | addi 3,3,16 | |
262 | 8: /* Move 8 bytes. */ | |
263 | bf 28,4f | |
264 | lwz 6,0(12) | |
265 | lwz 7,4(12) | |
266 | addi 12,12,8 | |
267 | stw 6,0(3) | |
268 | stw 7,4(3) | |
269 | addi 3,3,8 | |
270 | 4: /* Move 4 bytes. */ | |
271 | bf 29,2f | |
272 | lwz 6,0(12) | |
273 | addi 12,12,4 | |
274 | stw 6,0(3) | |
9c84384c | 275 | addi 3,3,4 |
04067002 UD |
276 | 2: /* Move 2-3 bytes. */ |
277 | bf 30,1f | |
278 | lhz 6,0(12) | |
9c84384c | 279 | sth 6,0(3) |
04067002 UD |
280 | bf 31,0f |
281 | lbz 7,2(12) | |
282 | stb 7,2(3) | |
283 | ld 3,-16(1) | |
284 | blr | |
285 | 1: /* Move 1 byte. */ | |
286 | bf 31,0f | |
287 | lbz 6,0(12) | |
288 | stb 6,0(3) | |
289 | 0: | |
290 | /* Return original dst pointer. */ | |
291 | ld 3,-16(1) | |
292 | blr | |
293 | ||
294 | /* Special case to copy 0-8 bytes. */ | |
295 | .align 4 | |
296 | .LE8: | |
297 | mr 12,4 | |
298 | bne cr6,4f | |
299 | /* Would have liked to use use ld/std here but the 630 processors are | |
9c84384c | 300 | slow for load/store doubles that are not at least word aligned. |
2ccdea26 | 301 | Unaligned Load/Store word execute with only a 1 cycle penalty. */ |
04067002 UD |
302 | lwz 6,0(4) |
303 | lwz 7,4(4) | |
304 | stw 6,0(3) | |
305 | stw 7,4(3) | |
306 | /* Return original dst pointer. */ | |
307 | ld 3,-16(1) | |
308 | blr | |
309 | .align 4 | |
310 | 4: bf 29,2b | |
311 | lwz 6,0(4) | |
312 | stw 6,0(3) | |
313 | 6: | |
314 | bf 30,5f | |
315 | lhz 7,4(4) | |
9c84384c | 316 | sth 7,4(3) |
04067002 UD |
317 | bf 31,0f |
318 | lbz 8,6(4) | |
319 | stb 8,6(3) | |
320 | ld 3,-16(1) | |
321 | blr | |
322 | .align 4 | |
9c84384c | 323 | 5: |
04067002 UD |
324 | bf 31,0f |
325 | lbz 6,4(4) | |
326 | stb 6,4(3) | |
327 | .align 4 | |
328 | 0: | |
329 | /* Return original dst pointer. */ | |
330 | ld 3,-16(1) | |
331 | blr | |
332 | ||
333 | .align 4 | |
334 | .L6: | |
335 | ||
336 | /* Copy doublewords where the destination is aligned but the source is | |
337 | not. Use aligned doubleword loads from the source, shifted to realign | |
338 | the data, to allow aligned destination stores. */ | |
339 | addi 11,9,-1 /* loop DW count is one less than total */ | |
340 | subf 5,10,12 | |
341 | sldi 10,10,3 | |
342 | mr 4,3 | |
343 | srdi 8,11,2 /* calculate the 32 byte loop count */ | |
344 | ld 6,0(5) | |
345 | mtcrf 0x01,11 | |
346 | cmpldi cr6,9,4 | |
347 | mtctr 8 | |
348 | ld 7,8(5) | |
349 | subfic 9,10,64 | |
350 | bf 30,1f | |
351 | ||
352 | /* there are at least two DWs to copy */ | |
759cfef3 AM |
353 | #ifdef __LITTLE_ENDIAN__ |
354 | srd 0,6,10 | |
355 | sld 8,7,9 | |
356 | #else | |
04067002 UD |
357 | sld 0,6,10 |
358 | srd 8,7,9 | |
759cfef3 | 359 | #endif |
04067002 UD |
360 | or 0,0,8 |
361 | ld 6,16(5) | |
362 | std 0,0(4) | |
759cfef3 AM |
363 | #ifdef __LITTLE_ENDIAN__ |
364 | srd 0,7,10 | |
365 | sld 8,6,9 | |
366 | #else | |
04067002 UD |
367 | sld 0,7,10 |
368 | srd 8,6,9 | |
759cfef3 | 369 | #endif |
04067002 UD |
370 | or 0,0,8 |
371 | ld 7,24(5) | |
372 | std 0,8(4) | |
373 | addi 4,4,16 | |
374 | addi 5,5,32 | |
375 | blt cr6,8f /* if total DWs = 3, then bypass loop */ | |
376 | bf 31,4f | |
377 | /* there is a third DW to copy */ | |
759cfef3 AM |
378 | #ifdef __LITTLE_ENDIAN__ |
379 | srd 0,6,10 | |
380 | sld 8,7,9 | |
381 | #else | |
04067002 UD |
382 | sld 0,6,10 |
383 | srd 8,7,9 | |
759cfef3 | 384 | #endif |
04067002 UD |
385 | or 0,0,8 |
386 | std 0,0(4) | |
387 | mr 6,7 | |
388 | ld 7,0(5) | |
389 | addi 5,5,8 | |
390 | addi 4,4,8 | |
391 | beq cr6,8f /* if total DWs = 4, then bypass loop */ | |
392 | b 4f | |
393 | .align 4 | |
394 | 1: | |
759cfef3 AM |
395 | #ifdef __LITTLE_ENDIAN__ |
396 | srd 0,6,10 | |
397 | sld 8,7,9 | |
398 | #else | |
04067002 UD |
399 | sld 0,6,10 |
400 | srd 8,7,9 | |
759cfef3 | 401 | #endif |
04067002 UD |
402 | addi 5,5,16 |
403 | or 0,0,8 | |
404 | bf 31,4f | |
405 | mr 6,7 | |
406 | ld 7,0(5) | |
407 | addi 5,5,8 | |
408 | std 0,0(4) | |
409 | addi 4,4,8 | |
410 | .align 4 | |
411 | /* copy 32 bytes at a time */ | |
759cfef3 AM |
412 | 4: |
413 | #ifdef __LITTLE_ENDIAN__ | |
414 | srd 0,6,10 | |
415 | sld 8,7,9 | |
416 | #else | |
417 | sld 0,6,10 | |
04067002 | 418 | srd 8,7,9 |
759cfef3 | 419 | #endif |
04067002 UD |
420 | or 0,0,8 |
421 | ld 6,0(5) | |
422 | std 0,0(4) | |
759cfef3 AM |
423 | #ifdef __LITTLE_ENDIAN__ |
424 | srd 0,7,10 | |
425 | sld 8,6,9 | |
426 | #else | |
04067002 UD |
427 | sld 0,7,10 |
428 | srd 8,6,9 | |
759cfef3 | 429 | #endif |
04067002 UD |
430 | or 0,0,8 |
431 | ld 7,8(5) | |
432 | std 0,8(4) | |
759cfef3 AM |
433 | #ifdef __LITTLE_ENDIAN__ |
434 | srd 0,6,10 | |
435 | sld 8,7,9 | |
436 | #else | |
04067002 UD |
437 | sld 0,6,10 |
438 | srd 8,7,9 | |
759cfef3 | 439 | #endif |
04067002 UD |
440 | or 0,0,8 |
441 | ld 6,16(5) | |
442 | std 0,16(4) | |
759cfef3 AM |
443 | #ifdef __LITTLE_ENDIAN__ |
444 | srd 0,7,10 | |
445 | sld 8,6,9 | |
446 | #else | |
04067002 UD |
447 | sld 0,7,10 |
448 | srd 8,6,9 | |
759cfef3 | 449 | #endif |
04067002 UD |
450 | or 0,0,8 |
451 | ld 7,24(5) | |
452 | std 0,24(4) | |
453 | addi 5,5,32 | |
454 | addi 4,4,32 | |
455 | bdnz+ 4b | |
456 | .align 4 | |
457 | 8: | |
458 | /* calculate and store the final DW */ | |
759cfef3 AM |
459 | #ifdef __LITTLE_ENDIAN__ |
460 | srd 0,6,10 | |
461 | sld 8,7,9 | |
462 | #else | |
04067002 UD |
463 | sld 0,6,10 |
464 | srd 8,7,9 | |
759cfef3 | 465 | #endif |
9c84384c | 466 | or 0,0,8 |
04067002 UD |
467 | std 0,0(4) |
468 | 3: | |
469 | rldicr 0,31,0,60 | |
470 | mtcrf 0x01,31 | |
471 | bne cr1,.L9 /* If the tail is 0 bytes we are done! */ | |
472 | /* Return original dst pointer. */ | |
473 | ld 31,-8(1) | |
474 | ld 3,-16(1) | |
475 | blr | |
72fd128a | 476 | END_GEN_TB (MEMCPY,TB_TOCLESS) |
04067002 | 477 | libc_hidden_builtin_def (memcpy) |