arch/hexagon/lib/memcpy.S

   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  */
  19
  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  */
 149
 150
 151 #define ptr_out         R0      /*  destination  pounter  */
 152 #define ptr_in          R1      /*  source pointer  */
 153 #define len             R2      /*  length of copy in bytes  */
 154
 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  */
 161
 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  */
 170
 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 */
 190
 191 #define ptr_in_p_128kernel      R5:4    /*  packed fetch pointer & kernel cnt */
 192
 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