| blob | a46093a8800abd0cd15c6618b1dc4c97b9020e7e |
1 /*
2 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
3 *
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 and
7 * only version 2 as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA.
18 */
20 /*
21 * Description
22 *
23 * library function for memcpy where length bytes are copied from
24 * ptr_in to ptr_out. ptr_out is returned unchanged.
25 * Allows any combination of alignment on input and output pointers
26 * and length from 0 to 2^32-1
27 *
28 * Restrictions
29 * The arrays should not overlap, the program will produce undefined output
30 * if they do.
31 * For blocks less than 16 bytes a byte by byte copy is performed. For
32 * 8byte alignments, and length multiples, a dword copy is performed up to
33 * 96bytes
34 * History
35 *
36 * DJH 5/15/09 Initial version 1.0
37 * DJH 6/ 1/09 Version 1.1 modified ABI to inlcude R16-R19
38 * DJH 7/12/09 Version 1.2 optimized codesize down to 760 was 840
39 * DJH 10/14/09 Version 1.3 added special loop for aligned case, was
40 * overreading bloated codesize back up to 892
41 * DJH 4/20/10 Version 1.4 fixed Ldword_loop_epilog loop to prevent loads
42 * occurring if only 1 left outstanding, fixes bug
43 * # 3888, corrected for all alignments. Peeled off
44 * 1 32byte chunk from kernel loop and extended 8byte
45 * loop at end to solve all combinations and prevent
46 * over read. Fixed Ldword_loop_prolog to prevent
47 * overread for blocks less than 48bytes. Reduced
48 * codesize to 752 bytes
49 * DJH 4/21/10 version 1.5 1.4 fix broke code for input block ends not
50 * aligned to dword boundaries,underwriting by 1
51 * byte, added detection for this and fixed. A
52 * little bloat.
53 * DJH 4/23/10 version 1.6 corrected stack error, R20 was not being restored
54 * always, fixed the error of R20 being modified
55 * before it was being saved
56 * Natural c model
57 * ===============
58 * void * memcpy(char * ptr_out, char * ptr_in, int length) {
59 * int i;
60 * if(length) for(i=0; i < length; i++) { ptr_out[i] = ptr_in[i]; }
61 * return(ptr_out);
62 * }
63 *
64 * Optimized memcpy function
65 * =========================
66 * void * memcpy(char * ptr_out, char * ptr_in, int len) {
67 * int i, prolog, kernel, epilog, mask;
68 * u8 offset;
69 * s64 data0, dataF8, data70;
70 *
71 * s64 * ptr8_in;
72 * s64 * ptr8_out;
73 * s32 * ptr4;
74 * s16 * ptr2;
75 *
76 * offset = ((int) ptr_in) & 7;
77 * ptr8_in = (s64 *) &ptr_in[-offset]; //read in the aligned pointers
78 *
79 * data70 = *ptr8_in++;
80 * dataF8 = *ptr8_in++;
81 *
82 * data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
83 *
84 * prolog = 32 - ((int) ptr_out);
85 * mask = 0x7fffffff >> HEXAGON_R_cl0_R(len);
86 * prolog = prolog & mask;
87 * kernel = len - prolog;
88 * epilog = kernel & 0x1F;
89 * kernel = kernel>>5;
90 *
91 * if (prolog & 1) { ptr_out[0] = (u8) data0; data0 >>= 8; ptr_out += 1;}
92 * ptr2 = (s16 *) &ptr_out[0];
93 * if (prolog & 2) { ptr2[0] = (u16) data0; data0 >>= 16; ptr_out += 2;}
94 * ptr4 = (s32 *) &ptr_out[0];
95 * if (prolog & 4) { ptr4[0] = (u32) data0; data0 >>= 32; ptr_out += 4;}
96 *
97 * offset = offset + (prolog & 7);
98 * if (offset >= 8) {
99 * data70 = dataF8;
100 * dataF8 = *ptr8_in++;
101 * }
102 * offset = offset & 0x7;
103 *
104 * prolog = prolog >> 3;
105 * if (prolog) for (i=0; i < prolog; i++) {
106 * data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
107 * ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
108 * data70 = dataF8;
109 * dataF8 = *ptr8_in++;
110 * }
111 * if(kernel) { kernel -= 1; epilog += 32; }
112 * if(kernel) for(i=0; i < kernel; i++) {
113 * data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
114 * ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
115 * data70 = *ptr8_in++;
116 *
117 * data0 = HEXAGON_P_valignb_PPp(data70, dataF8, offset);
118 * ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
119 * dataF8 = *ptr8_in++;
120 *
121 * data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
122 * ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
123 * data70 = *ptr8_in++;
124 *
125 * data0 = HEXAGON_P_valignb_PPp(data70, dataF8, offset);
126 * ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
127 * dataF8 = *ptr8_in++;
128 * }
129 * epilogdws = epilog >> 3;
130 * if (epilogdws) for (i=0; i < epilogdws; i++) {
131 * data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
132 * ptr8_out = (s64 *) &ptr_out[0]; *ptr8_out = data0; ptr_out += 8;
133 * data70 = dataF8;
134 * dataF8 = *ptr8_in++;
135 * }
136 * data0 = HEXAGON_P_valignb_PPp(dataF8, data70, offset);
137 *
138 * ptr4 = (s32 *) &ptr_out[0];
139 * if (epilog & 4) { ptr4[0] = (u32) data0; data0 >>= 32; ptr_out += 4;}
140 * ptr2 = (s16 *) &ptr_out[0];
141 * if (epilog & 2) { ptr2[0] = (u16) data0; data0 >>= 16; ptr_out += 2;}
142 * if (epilog & 1) { *ptr_out++ = (u8) data0; }
143 *
144 * return(ptr_out - length);
145 * }
146 *
147 * Codesize : 784 bytes
148 */
151 #define ptr_out R0 /* destination pounter */
152 #define ptr_in R1 /* source pointer */
153 #define len R2 /* length of copy in bytes */
155 #define data70 R13:12 /* lo 8 bytes of non-aligned transfer */
156 #define dataF8 R11:10 /* hi 8 bytes of non-aligned transfer */
157 #define ldata0 R7:6 /* even 8 bytes chunks */
158 #define ldata1 R25:24 /* odd 8 bytes chunks */
159 #define data1 R7 /* lower 8 bytes of ldata1 */
160 #define data0 R6 /* lower 8 bytes of ldata0 */
162 #define ifbyte p0 /* if transfer has bytes in epilog/prolog */
163 #define ifhword p0 /* if transfer has shorts in epilog/prolog */
164 #define ifword p0 /* if transfer has words in epilog/prolog */
165 #define noprolog p0 /* no prolog, xfer starts at 32byte */
166 #define nokernel p1 /* no 32byte multiple block in the transfer */
167 #define noepilog p0 /* no epilog, xfer ends on 32byte boundary */
168 #define align p2 /* alignment of input rel to 8byte boundary */
169 #define kernel1 p0 /* kernel count == 1 */
171 #define dalign R25 /* rel alignment of input to output data */
172 #define star3 R16 /* number bytes in prolog - dwords */
173 #define rest R8 /* length - prolog bytes */
174 #define back R7 /* nr bytes > dword boundary in src block */
175 #define epilog R3 /* bytes in epilog */
176 #define inc R15:14 /* inc kernel by -1 and defetch ptr by 32 */
177 #define kernel R4 /* number of 32byte chunks in kernel */
178 #define ptr_in_p_128 R5 /* pointer for prefetch of input data */
179 #define mask R8 /* mask used to determine prolog size */
180 #define shift R8 /* used to work a shifter to extract bytes */
181 #define shift2 R5 /* in epilog to workshifter to extract bytes */
182 #define prolog R15 /* bytes in prolog */
183 #define epilogdws R15 /* number dwords in epilog */
184 #define shiftb R14 /* used to extract bytes */
185 #define offset R9 /* same as align in reg */
186 #define ptr_out_p_32 R17 /* pointer to output dczero */
187 #define align888 R14 /* if simple dword loop can be used */
188 #define len8 R9 /* number of dwords in length */
189 #define over R20 /* nr of bytes > last inp buf dword boundary */
191 #define ptr_in_p_128kernel R5:4 /* packed fetch pointer & kernel cnt */
193 .section .text
194 .p2align 4
195 .global memcpy
196 .type memcpy, @function
197 memcpy:
198 {
199 p2 = cmp.eq(len, #0); /* =0 */
200 align888 = or(ptr_in, ptr_out); /* %8 < 97 */
201 p0 = cmp.gtu(len, #23); /* %1, <24 */
202 p1 = cmp.eq(ptr_in, ptr_out); /* attempt to overwrite self */
203 }
204 {
205 p1 = or(p2, p1);
206 p3 = cmp.gtu(len, #95); /* %8 < 97 */
207 align888 = or(align888, len); /* %8 < 97 */
208 len8 = lsr(len, #3); /* %8 < 97 */
209 }
210 {
211 dcfetch(ptr_in); /* zero/ptrin=ptrout causes fetch */
212 p2 = bitsclr(align888, #7); /* %8 < 97 */
213 if(p1) jumpr r31; /* =0 */
214 }
215 {
216 p2 = and(p2,!p3); /* %8 < 97 */
217 if (p2.new) len = add(len, #-8); /* %8 < 97 */
218 if (p2.new) jump:NT .Ldwordaligned; /* %8 < 97 */
219 }
220 {
221 if(!p0) jump .Lbytes23orless; /* %1, <24 */
222 mask.l = #LO(0x7fffffff);
223 /* all bytes before line multiples of data */
224 prolog = sub(#0, ptr_out);
225 }
226 {
227 /* save r31 on stack, decrement sp by 16 */
228 allocframe(#24);
229 mask.h = #HI(0x7fffffff);
230 ptr_in_p_128 = add(ptr_in, #32);
231 back = cl0(len);
232 }
233 {
234 memd(sp+#0) = R17:16; /* save r16,r17 on stack6 */
235 r31.l = #LO(.Lmemcpy_return); /* set up final return pointer */
236 prolog &= lsr(mask, back);
237 offset = and(ptr_in, #7);
238 }
239 {
240 memd(sp+#8) = R25:24; /* save r25,r24 on stack */
241 dalign = sub(ptr_out, ptr_in);
242 r31.h = #HI(.Lmemcpy_return); /* set up final return pointer */
243 }
244 {
245 /* see if there if input buffer end if aligned */
246 over = add(len, ptr_in);
247 back = add(len, offset);
248 memd(sp+#16) = R21:20; /* save r20,r21 on stack */
249 }
250 {
251 noprolog = bitsclr(prolog, #7);
252 prolog = and(prolog, #31);
253 dcfetch(ptr_in_p_128);
254 ptr_in_p_128 = add(ptr_in_p_128, #32);
255 }
256 {
257 kernel = sub(len, prolog);
258 shift = asl(prolog, #3);
259 star3 = and(prolog, #7);
260 ptr_in = and(ptr_in, #-8);
261 }
262 {
263 prolog = lsr(prolog, #3);
264 epilog = and(kernel, #31);
265 ptr_out_p_32 = add(ptr_out, prolog);
266 over = and(over, #7);
267 }
268 {
269 p3 = cmp.gtu(back, #8);
270 kernel = lsr(kernel, #5);
271 dcfetch(ptr_in_p_128);
272 ptr_in_p_128 = add(ptr_in_p_128, #32);
273 }
274 {
275 p1 = cmp.eq(prolog, #0);
276 if(!p1.new) prolog = add(prolog, #1);
277 dcfetch(ptr_in_p_128); /* reserve the line 64bytes on */
278 ptr_in_p_128 = add(ptr_in_p_128, #32);
279 }
280 {
281 nokernel = cmp.eq(kernel,#0);
282 dcfetch(ptr_in_p_128); /* reserve the line 64bytes on */
283 ptr_in_p_128 = add(ptr_in_p_128, #32);
284 shiftb = and(shift, #8);
285 }
286 {
287 dcfetch(ptr_in_p_128); /* reserve the line 64bytes on */
288 ptr_in_p_128 = add(ptr_in_p_128, #32);
289 if(nokernel) jump .Lskip64;
290 p2 = cmp.eq(kernel, #1); /* skip ovr if kernel == 0 */
291 }
292 {
293 dczeroa(ptr_out_p_32);
294 /* don't advance pointer */
295 if(!p2) ptr_out_p_32 = add(ptr_out_p_32, #32);
296 }
297 {
298 dalign = and(dalign, #31);
299 dczeroa(ptr_out_p_32);
300 }
301 .Lskip64:
302 {
303 data70 = memd(ptr_in++#16);
304 if(p3) dataF8 = memd(ptr_in+#8);
305 if(noprolog) jump .Lnoprolog32;
306 align = offset;
307 }
308 /* upto initial 7 bytes */
309 {
310 ldata0 = valignb(dataF8, data70, align);
311 ifbyte = tstbit(shift,#3);
312 offset = add(offset, star3);
313 }
314 {
315 if(ifbyte) memb(ptr_out++#1) = data0;
316 ldata0 = lsr(ldata0, shiftb);
317 shiftb = and(shift, #16);
318 ifhword = tstbit(shift,#4);
319 }
320 {
321 if(ifhword) memh(ptr_out++#2) = data0;
322 ldata0 = lsr(ldata0, shiftb);
323 ifword = tstbit(shift,#5);
324 p2 = cmp.gtu(offset, #7);
325 }
326 {
327 if(ifword) memw(ptr_out++#4) = data0;
328 if(p2) data70 = dataF8;
329 if(p2) dataF8 = memd(ptr_in++#8); /* another 8 bytes */
330 align = offset;
331 }
332 .Lnoprolog32:
333 {
334 p3 = sp1loop0(.Ldword_loop_prolog, prolog)
335 rest = sub(len, star3); /* whats left after the loop */
336 p0 = cmp.gt(over, #0);
337 }
338 if(p0) rest = add(rest, #16);
339 .Ldword_loop_prolog:
340 {
341 if(p3) memd(ptr_out++#8) = ldata0;
342 ldata0 = valignb(dataF8, data70, align);
343 p0 = cmp.gt(rest, #16);
344 }
345 {
346 data70 = dataF8;
347 if(p0) dataF8 = memd(ptr_in++#8);
348 rest = add(rest, #-8);
349 }:endloop0
350 .Lkernel:
351 {
352 /* kernel is at least 32bytes */
353 p3 = cmp.gtu(kernel, #0);
354 /* last itn. remove edge effects */
355 if(p3.new) kernel = add(kernel, #-1);
356 /* dealt with in last dword loop */
357 if(p3.new) epilog = add(epilog, #32);
358 }
359 {
360 nokernel = cmp.eq(kernel, #0); /* after adjustment, recheck */
361 if(nokernel.new) jump:NT .Lepilog; /* likely not taken */
362 inc = combine(#32, #-1);
363 p3 = cmp.gtu(dalign, #24);
364 }
365 {
366 if(p3) jump .Lodd_alignment;
367 }
368 {
369 loop0(.Loword_loop_25to31, kernel);
370 kernel1 = cmp.gtu(kernel, #1);
371 rest = kernel;
372 }
373 .falign
374 .Loword_loop_25to31:
375 {
376 dcfetch(ptr_in_p_128); /* prefetch 4 lines ahead */
377 if(kernel1) ptr_out_p_32 = add(ptr_out_p_32, #32);
378 }
379 {
380 dczeroa(ptr_out_p_32); /* reserve the next 32bytes in cache */
381 p3 = cmp.eq(kernel, rest);
382 }
383 {
384 /* kernel -= 1 */
385 ptr_in_p_128kernel = vaddw(ptr_in_p_128kernel, inc);
386 /* kill write on first iteration */
387 if(!p3) memd(ptr_out++#8) = ldata1;
388 ldata1 = valignb(dataF8, data70, align);
389 data70 = memd(ptr_in++#8);
390 }
391 {
392 memd(ptr_out++#8) = ldata0;
393 ldata0 = valignb(data70, dataF8, align);
394 dataF8 = memd(ptr_in++#8);
395 }
396 {
397 memd(ptr_out++#8) = ldata1;
398 ldata1 = valignb(dataF8, data70, align);
399 data70 = memd(ptr_in++#8);
400 }
401 {
402 memd(ptr_out++#8) = ldata0;
403 ldata0 = valignb(data70, dataF8, align);
404 dataF8 = memd(ptr_in++#8);
405 kernel1 = cmp.gtu(kernel, #1);
406 }:endloop0
407 {
408 memd(ptr_out++#8) = ldata1;
409 jump .Lepilog;
410 }
411 .Lodd_alignment:
412 {
413 loop0(.Loword_loop_00to24, kernel);
414 kernel1 = cmp.gtu(kernel, #1);
415 rest = add(kernel, #-1);
416 }
417 .falign
418 .Loword_loop_00to24:
419 {
420 dcfetch(ptr_in_p_128); /* prefetch 4 lines ahead */
421 ptr_in_p_128kernel = vaddw(ptr_in_p_128kernel, inc);
422 if(kernel1) ptr_out_p_32 = add(ptr_out_p_32, #32);
423 }
424 {
425 dczeroa(ptr_out_p_32); /* reserve the next 32bytes in cache */
426 }
427 {
428 memd(ptr_out++#8) = ldata0;
429 ldata0 = valignb(dataF8, data70, align);
430 data70 = memd(ptr_in++#8);
431 }
432 {
433 memd(ptr_out++#8) = ldata0;
434 ldata0 = valignb(data70, dataF8, align);
435 dataF8 = memd(ptr_in++#8);
436 }
437 {
438 memd(ptr_out++#8) = ldata0;
439 ldata0 = valignb(dataF8, data70, align);
440 data70 = memd(ptr_in++#8);
441 }
442 {
443 memd(ptr_out++#8) = ldata0;
444 ldata0 = valignb(data70, dataF8, align);
445 dataF8 = memd(ptr_in++#8);
446 kernel1 = cmp.gtu(kernel, #1);
447 }:endloop0
448 .Lepilog:
449 {
450 noepilog = cmp.eq(epilog,#0);
451 epilogdws = lsr(epilog, #3);
452 kernel = and(epilog, #7);
453 }
454 {
455 if(noepilog) jumpr r31;
456 if(noepilog) ptr_out = sub(ptr_out, len);
457 p3 = cmp.eq(epilogdws, #0);
458 shift2 = asl(epilog, #3);
459 }
460 {
461 shiftb = and(shift2, #32);
462 ifword = tstbit(epilog,#2);
463 if(p3) jump .Lepilog60;
464 if(!p3) epilog = add(epilog, #-16);
465 }
466 {
467 loop0(.Ldword_loop_epilog, epilogdws);
468 /* stop criteria is lsbs unless = 0 then its 8 */
469 p3 = cmp.eq(kernel, #0);
470 if(p3.new) kernel= #8;
471 p1 = cmp.gt(over, #0);
472 }
473 /* if not aligned to end of buffer execute 1 more iteration */
474 if(p1) kernel= #0;
475 .Ldword_loop_epilog:
476 {
477 memd(ptr_out++#8) = ldata0;
478 ldata0 = valignb(dataF8, data70, align);
479 p3 = cmp.gt(epilog, kernel);
480 }
481 {
482 data70 = dataF8;
483 if(p3) dataF8 = memd(ptr_in++#8);
484 epilog = add(epilog, #-8);
485 }:endloop0
486 /* copy last 7 bytes */
487 .Lepilog60:
488 {
489 if(ifword) memw(ptr_out++#4) = data0;
490 ldata0 = lsr(ldata0, shiftb);
491 ifhword = tstbit(epilog,#1);
492 shiftb = and(shift2, #16);
493 }
494 {
495 if(ifhword) memh(ptr_out++#2) = data0;
496 ldata0 = lsr(ldata0, shiftb);
497 ifbyte = tstbit(epilog,#0);
498 if(ifbyte.new) len = add(len, #-1);
499 }
500 {
501 if(ifbyte) memb(ptr_out) = data0;
502 ptr_out = sub(ptr_out, len); /* return dest pointer */
503 jumpr r31;
504 }
505 /* do byte copy for small n */
506 .Lbytes23orless:
507 {
508 p3 = sp1loop0(.Lbyte_copy, len);
509 len = add(len, #-1);
510 }
511 .Lbyte_copy:
512 {
513 data0 = memb(ptr_in++#1);
514 if(p3) memb(ptr_out++#1) = data0;
515 }:endloop0
516 {
517 memb(ptr_out) = data0;
518 ptr_out = sub(ptr_out, len);
519 jumpr r31;
520 }
521 /* do dword copies for aligned in, out and length */
522 .Ldwordaligned:
523 {
524 p3 = sp1loop0(.Ldword_copy, len8);
525 }
526 .Ldword_copy:
527 {
528 if(p3) memd(ptr_out++#8) = ldata0;
529 ldata0 = memd(ptr_in++#8);
530 }:endloop0
531 {
532 memd(ptr_out) = ldata0;
533 ptr_out = sub(ptr_out, len);
534 jumpr r31; /* return to function caller */
535 }
536 .Lmemcpy_return:
537 r21:20 = memd(sp+#16); /* restore r20+r21 */
538 {
539 r25:24 = memd(sp+#8); /* restore r24+r25 */
540 r17:16 = memd(sp+#0); /* restore r16+r17 */
541 }
542 deallocframe; /* restore r31 and incrment stack by 16 */
543 jumpr r31