lib/match.c

   1 /* match.s -- optional optimized asm version of longest match in deflate.c
   2
   3    Copyright (C) 2002, 2006, 2009-2011 Free Software Foundation, Inc.
   4    Copyright (C) 1992-1993 Jean-loup Gailly
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3, or (at your option)
   9    any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software Foundation,
  18    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  19
  20 /*
  21  * The 68020 version has been written by Francesco Potorti` <pot@cnuce.cnr.it>
  22  * with adaptations by Carsten Steger <stegerc@informatik.tu-muenchen.de>,
  23  * Andreas Schwab <schwab@lamothe.informatik.uni-dortmund.de> and
  24  * Kristoffer Eriksson <ske@pkmab.se>
  25  *
  26  * The ia64 version has been written by Sverre Jarp (HP Labs) 2001-2002.
  27  * Unwind directives and some reformatting for better readability added by
  28  * David Mosberger-Tang <davidm@hpl.hp.com>.
  29  */
  30
  31 /* Preprocess with -DNO_UNDERLINE if your C compiler does not prefix
  32  * external symbols with an underline character '_'.
  33  */
  34 #ifdef NO_UNDERLINE
  35 #  define _prev             prev
  36 #  define _window           window
  37 #  define _match_start      match_start
  38 #  define _prev_length      prev_length
  39 #  define _good_match       good_match
  40 #  define _nice_match       nice_match
  41 #  define _strstart         strstart
  42 #  define _max_chain_length max_chain_length
  43
  44 #  define _match_init       match_init
  45 #  define _longest_match    longest_match
  46 #endif
  47
  48 #ifdef DYN_ALLOC
  49   error: DYN_ALLOC not yet supported in match.s
  50 #endif
  51
  52 #if defined(i386) || defined(_I386) || defined(__i386) || defined(__i386__)
  53
  54 /* This version is for 386 Unix or OS/2 in 32 bit mode.
  55  * Warning: it uses the AT&T syntax: mov source,dest
  56  * This file is only optional. If you want to force the C version,
  57  * add -DNO_ASM to CFLAGS in Makefile and set OBJA to an empty string.
  58  * If you have reduced WSIZE in gzip.h, then change its value below.
  59  * This version assumes static allocation of the arrays (-DDYN_ALLOC not used).
  60  */
  61
  62         .file   "match.S"
  63
  64 #define MAX_MATCH       258
  65 #define MAX_MATCH2      $128 /* MAX_MATCH/2-1 */
  66 #define MIN_MATCH       3
  67 #define    WSIZE        $32768
  68 #define MAX_DIST        WSIZE - MAX_MATCH - MIN_MATCH - 1
  69
  70         .globl  _match_init
  71         .globl  _longest_match
  72
  73         .text
  74
  75 _match_init:
  76         ret
  77
  78 /*-----------------------------------------------------------------------
  79  * Set match_start to the longest match starting at the given string and
  80  * return its length. Matches shorter or equal to prev_length are discarded,
  81  * in which case the result is equal to prev_length and match_start is
  82  * garbage.
  83  * IN assertions: cur_match is the head of the hash chain for the current
  84  *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
  85  */
  86
  87 _longest_match: /* int longest_match(cur_match) */
  88
  89 #define cur_match   20(%esp)
  90      /* return address */               /* esp+16 */
  91         push    %ebp                    /* esp+12 */
  92         push    %edi                    /* esp+8  */
  93         push    %esi                    /* esp+4  */
  94         push    %ebx                    /* esp    */
  95
  96 /*
  97  *      match        equ esi
  98  *      scan         equ edi
  99  *      chain_length equ ebp
 100  *      best_len     equ ebx
 101  *      limit        equ edx
 102  */
 103         mov     cur_match,%esi
 104         mov     _max_chain_length,%ebp /* chain_length = max_chain_length */
 105         mov     _strstart,%edi
 106         mov     %edi,%edx
 107         sub     MAX_DIST,%edx          /* limit = strstart-MAX_DIST */
 108         jae     limit_ok
 109         sub     %edx,%edx              /* limit = NIL */
 110 limit_ok:
 111         add     $2+_window,%edi        /* edi = offset(window+strstart+2) */
 112         mov     _prev_length,%ebx      /* best_len = prev_length */
 113         movw    -3(%ebx,%edi),%ax      /* ax = scan[best_len-1..best_len] */
 114         movw    -2(%edi),%cx           /* cx = scan[0..1] */
 115         cmp     _good_match,%ebx       /* do we have a good match already? */
 116         jb      do_scan
 117         shr     $2,%ebp                /* chain_length >>= 2 */
 118         jmp     do_scan
 119
 120         .align  4
 121 long_loop:
 122 /* at this point, edi == scan+2, esi == cur_match */
 123         movw    -3(%ebx,%edi),%ax       /* ax = scan[best_len-1..best_len] */
 124         movw     -2(%edi),%cx           /* cx = scan[0..1] */
 125 short_loop:
 126 /*
 127  * at this point, di == scan+2, si == cur_match,
 128  * ax = scan[best_len-1..best_len] and cx = scan[0..1]
 129  */
 130         and     WSIZE-1, %esi
 131         movw    _prev(%esi,%esi),%si    /* cur_match = prev[cur_match] */
 132                                         /* top word of esi is still 0 */
 133         cmp     %edx,%esi               /* cur_match <= limit ? */
 134         jbe     the_end
 135         dec     %ebp                    /* --chain_length */
 136         jz      the_end
 137 do_scan:
 138         cmpw    _window-1(%ebx,%esi),%ax/* check match at best_len-1 */
 139         jne     short_loop
 140         cmpw    _window(%esi),%cx       /* check min_match_length match */
 141         jne     short_loop
 142
 143         lea     _window+2(%esi),%esi    /* si = match */
 144         mov     %edi,%eax               /* ax = scan+2 */
 145         mov     MAX_MATCH2,%ecx         /* scan for at most MAX_MATCH bytes */
 146         rep;    cmpsw                   /* loop until mismatch */
 147         je      maxmatch                /* match of length MAX_MATCH? */
 148 mismatch:
 149         movb    -2(%edi),%cl        /* mismatch on first or second byte? */
 150         subb    -2(%esi),%cl        /* cl = 0 if first bytes equal */
 151         xchg    %edi,%eax           /* edi = scan+2, eax = end of scan */
 152         sub     %edi,%eax           /* eax = len */
 153         sub     %eax,%esi           /* esi = cur_match + 2 + offset(window) */
 154         sub     $2+_window,%esi     /* esi = cur_match */
 155         subb    $1,%cl              /* set carry if cl == 0 (cannot use DEC) */
 156         adc     $0,%eax             /* eax = carry ? len+1 : len */
 157         cmp     %ebx,%eax           /* len > best_len ? */
 158         jle     long_loop
 159         mov     %esi,_match_start       /* match_start = cur_match */
 160         mov     %eax,%ebx               /* ebx = best_len = len */
 161         cmp     _nice_match,%eax        /* len >= nice_match ? */
 162         jl      long_loop
 163 the_end:
 164         mov     %ebx,%eax               /* result = eax = best_len */
 165         pop     %ebx
 166         pop     %esi
 167         pop     %edi
 168         pop     %ebp
 169         ret
 170 maxmatch:
 171         cmpsb
 172         jmp     mismatch
 173
 174 #else
 175
 176 /* ======================== 680x0 version ================================= */
 177
 178 #if defined(m68k)||defined(mc68k)||defined(__mc68000__)||defined(__MC68000__)
 179 #  ifndef mc68000
 180 #    define mc68000
 181 #  endif
 182 #endif
 183
 184 #if defined(__mc68020__) || defined(__MC68020__) || defined(sysV68)
 185 #  ifndef mc68020
 186 #    define mc68020
 187 #  endif
 188 #endif
 189
 190 #if defined(mc68020) || defined(mc68000)
 191
 192 #if (defined(mc68020) || defined(NeXT)) && !defined(UNALIGNED_OK)
 193 #  define UNALIGNED_OK
 194 #endif
 195
 196 #ifdef sysV68  /* Try Motorola Delta style */
 197
 198 #  define GLOBAL(symbol)        global  symbol
 199 #  define TEXT                  text
 200 #  define FILE(filename)        file    filename
 201 #  define invert_maybe(src,dst) dst,src
 202 #  define imm(data)             &data
 203 #  define reg(register)         %register
 204
 205 #  define addl                  add.l
 206 #  define addql                 addq.l
 207 #  define blos                  blo.b
 208 #  define bhis                  bhi.b
 209 #  define bras                  bra.b
 210 #  define clrl                  clr.l
 211 #  define cmpmb                 cmpm.b
 212 #  define cmpw                  cmp.w
 213 #  define cmpl                  cmp.l
 214 #  define lslw                  lsl.w
 215 #  define lsrl                  lsr.l
 216 #  define movel                 move.l
 217 #  define movew                 move.w
 218 #  define moveb                 move.b
 219 #  define moveml                movem.l
 220 #  define subl                  sub.l
 221 #  define subw                  sub.w
 222 #  define subql                 subq.l
 223
 224 #  define IndBase(bd,An)        (bd,An)
 225 #  define IndBaseNdxl(bd,An,Xn) (bd,An,Xn.l)
 226 #  define IndBaseNdxw(bd,An,Xn) (bd,An,Xn.w)
 227 #  define predec(An)            -(An)
 228 #  define postinc(An)           (An)+
 229
 230 #else /* default style (Sun 3, NeXT, Amiga, Atari) */
 231
 232 #  define GLOBAL(symbol)        .globl  symbol
 233 #  define TEXT                  .text
 234 #  define FILE(filename)        .even
 235 #  define invert_maybe(src,dst) src,dst
 236 #  if defined(sun) || defined(mc68k)
 237 #    define imm(data)           #data
 238 #  else
 239 #    define imm(data)           \#data
 240 #  endif
 241 #  define reg(register)         register
 242
 243 #  define blos                  bcss
 244 #  if defined(sun) || defined(mc68k)
 245 #    define movel               movl
 246 #    define movew               movw
 247 #    define moveb               movb
 248 #  endif
 249 #  define IndBase(bd,An)        An@(bd)
 250 #  define IndBaseNdxl(bd,An,Xn) An@(bd,Xn:l)
 251 #  define IndBaseNdxw(bd,An,Xn) An@(bd,Xn:w)
 252 #  define predec(An)            An@-
 253 #  define postinc(An)           An@+
 254
 255 #endif  /* styles */
 256
 257 #define Best_Len        reg(d0)         /* unsigned */
 258 #define Cur_Match       reg(d1)         /* Ipos */
 259 #define Loop_Counter    reg(d2)         /* int */
 260 #define Scan_Start      reg(d3)         /* unsigned short */
 261 #define Scan_End        reg(d4)         /* unsigned short */
 262 #define Limit           reg(d5)         /* IPos */
 263 #define Chain_Length    reg(d6)         /* unsigned */
 264 #define Scan_Test       reg(d7)
 265 #define Scan            reg(a0)         /* *uch */
 266 #define Match           reg(a1)         /* *uch */
 267 #define Prev_Address    reg(a2)         /* *Pos */
 268 #define Scan_Ini        reg(a3)         /* *uch */
 269 #define Match_Ini       reg(a4)         /* *uch */
 270 #define Stack_Pointer   reg(sp)
 271
 272 #define MAX_MATCH       258
 273 #define MIN_MATCH       3
 274 #define WSIZE           32768
 275 #define MAX_DIST        (WSIZE - MAX_MATCH - MIN_MATCH - 1)
 276
 277         GLOBAL  (_match_init)
 278         GLOBAL  (_longest_match)
 279
 280         TEXT
 281
 282         FILE    ("match.S")
 283
 284 _match_init:
 285         rts
 286
 287 /*-----------------------------------------------------------------------
 288  * Set match_start to the longest match starting at the given string and
 289  * return its length. Matches shorter or equal to prev_length are discarded,
 290  * in which case the result is equal to prev_length and match_start is
 291  * garbage.
 292  * IN assertions: cur_match is the head of the hash chain for the current
 293  *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
 294  */
 295
 296 /* int longest_match (cur_match) */
 297
 298 #ifdef UNALIGNED_OK
 299 #  define pushreg       15928           /* d2-d6/a2-a4 */
 300 #  define popreg        7292
 301 #else
 302 #  define pushreg       16184           /* d2-d7/a2-a4 */
 303 #  define popreg        7420
 304 #endif
 305
 306 _longest_match:
 307         movel   IndBase(4,Stack_Pointer),Cur_Match
 308         moveml  imm(pushreg),predec(Stack_Pointer)
 309         movel   _max_chain_length,Chain_Length
 310         movel   _prev_length,Best_Len
 311         movel   imm(_prev),Prev_Address
 312         movel   imm(_window+MIN_MATCH),Match_Ini
 313         movel   _strstart,Limit
 314         movel   Match_Ini,Scan_Ini
 315         addl    Limit,Scan_Ini
 316         subw    imm(MAX_DIST),Limit
 317         bhis    L__limit_ok
 318         clrl    Limit
 319 L__limit_ok:
 320         cmpl    invert_maybe(_good_match,Best_Len)
 321         blos    L__length_ok
 322         lsrl    imm(2),Chain_Length
 323 L__length_ok:
 324         subql   imm(1),Chain_Length
 325 #ifdef UNALIGNED_OK
 326         movew   IndBase(-MIN_MATCH,Scan_Ini),Scan_Start
 327         movew   IndBaseNdxw(-MIN_MATCH-1,Scan_Ini,Best_Len),Scan_End
 328 #else
 329         moveb   IndBase(-MIN_MATCH,Scan_Ini),Scan_Start
 330         lslw    imm(8),Scan_Start
 331         moveb   IndBase(-MIN_MATCH+1,Scan_Ini),Scan_Start
 332         moveb   IndBaseNdxw(-MIN_MATCH-1,Scan_Ini,Best_Len),Scan_End
 333         lslw    imm(8),Scan_End
 334         moveb   IndBaseNdxw(-MIN_MATCH,Scan_Ini,Best_Len),Scan_End
 335 #endif
 336         bras    L__do_scan
 337
 338 L__long_loop:
 339 #ifdef UNALIGNED_OK
 340         movew   IndBaseNdxw(-MIN_MATCH-1,Scan_Ini,Best_Len),Scan_End
 341 #else
 342         moveb   IndBaseNdxw(-MIN_MATCH-1,Scan_Ini,Best_Len),Scan_End
 343         lslw    imm(8),Scan_End
 344         moveb   IndBaseNdxw(-MIN_MATCH,Scan_Ini,Best_Len),Scan_End
 345 #endif
 346
 347 L__short_loop:
 348         lslw    imm(1),Cur_Match
 349         movew   IndBaseNdxl(0,Prev_Address,Cur_Match),Cur_Match
 350         cmpw    invert_maybe(Limit,Cur_Match)
 351         dbls    Chain_Length,L__do_scan
 352         bras    L__return
 353
 354 L__do_scan:
 355         movel   Match_Ini,Match
 356         addl    Cur_Match,Match
 357 #ifdef UNALIGNED_OK
 358         cmpw    invert_maybe(IndBaseNdxw(-MIN_MATCH-1,Match,Best_Len),Scan_End)
 359         bne     L__short_loop
 360         cmpw    invert_maybe(IndBase(-MIN_MATCH,Match),Scan_Start)
 361         bne     L__short_loop
 362 #else
 363         moveb   IndBaseNdxw(-MIN_MATCH-1,Match,Best_Len),Scan_Test
 364         lslw    imm(8),Scan_Test
 365         moveb   IndBaseNdxw(-MIN_MATCH,Match,Best_Len),Scan_Test
 366         cmpw    invert_maybe(Scan_Test,Scan_End)
 367         bne     L__short_loop
 368         moveb   IndBase(-MIN_MATCH,Match),Scan_Test
 369         lslw    imm(8),Scan_Test
 370         moveb   IndBase(-MIN_MATCH+1,Match),Scan_Test
 371         cmpw    invert_maybe(Scan_Test,Scan_Start)
 372         bne     L__short_loop
 373 #endif
 374
 375         movew   imm((MAX_MATCH-MIN_MATCH+1)-1),Loop_Counter
 376         movel   Scan_Ini,Scan
 377 L__scan_loop:
 378         cmpmb   postinc(Match),postinc(Scan)
 379         dbne    Loop_Counter,L__scan_loop
 380
 381         subl    Scan_Ini,Scan
 382         addql   imm(MIN_MATCH-1),Scan
 383         cmpl    invert_maybe(Best_Len,Scan)
 384         bls     L__short_loop
 385         movel   Scan,Best_Len
 386         movel   Cur_Match,_match_start
 387         cmpl    invert_maybe(_nice_match,Best_Len)
 388         blos    L__long_loop
 389 L__return:
 390         moveml  postinc(Stack_Pointer),imm(popreg)
 391         rts
 392
 393 #else
 394
 395 # if defined (__ia64__)
 396
 397 /* ======================== ia64 version ================================= */
 398
 399 /*
 400  * 'longest_match.S' (assembly program for gzip for the IA-64 architecture)
 401  *
 402  * Optimised for McKinley, but with Merced-compatibility, such as MIB+MIB, used wherever
 403  * possible.
 404  *
 405  * Copyright: Sverre Jarp (HP Labs) 2001-2002
 406  *
 407  * See deflate.c for c-version
 408  * Version 2 - Optimize the outer loop
 409  */
 410
 411 #include <endian.h>
 412
 413 #if __BYTE_ORDER == ____BIG_ENDIAN
 414 #define  first  shl
 415 #define  second shr.u
 416 #define  count  czx1.l
 417 #else
 418 #define  first  shr.u
 419 #define  second shl
 420 #define  count  czx1.r
 421 #endif
 422
 423 // 24 rotating register (r32 - r55)
 424
 425 #define s_vmatch0               r32
 426 #define s_vmatch1               r33
 427 #define s_vmatbst               r34
 428 #define s_vmatbst1              r35
 429 #define s_amatblen              r36
 430
 431 #define s_tm1                   r56
 432 #define s_tm2                   r57
 433 #define s_tm3                   r58
 434 #define s_tm4                   r59
 435 #define s_tm5                   r60
 436 #define s_tm6                   r61
 437 #define s_tm7                   r62
 438 #define s_tm8                   r63
 439
 440 #define s_vlen                  r31
 441 #define s_vstrstart             r30
 442 #define s_vchainlen             r29
 443 #define s_awinbest              r28
 444 #define s_vcurmatch             r27
 445 #define s_vlimit                r26
 446 #define s_vscanend              r25
 447 #define s_vscanend1             r24
 448 #define s_anicematch            r23
 449 #define s_vscan0                r22
 450 #define s_vscan1                r21
 451
 452 #define s_aprev                 r20
 453 #define s_awindow               r19
 454 #define s_amatchstart           r18
 455 #define s_ascan                 r17
 456 #define s_amatch                r16
 457 #define s_wmask                 r15
 458 #define s_ascanend              r14
 459
 460 #define s_vspec_cmatch          r11             // next iteration
 461 #define s_lcsave                r10
 462 #define s_prsave                r9
 463 #define s_vbestlen              r8              // return register
 464
 465 #define s_vscan3                r3
 466 #define s_vmatch3               r2
 467
 468 #define p_no                    p2
 469 #define p_yes                   p3
 470 #define p_shf                   p4              //
 471 #define p_bn2                   p5              // Use in loop (indicating bestlen != 2)
 472
 473 #define p_nbs                   p9              // not new best_len
 474 #define p_nnc                   p10             // not nice_length
 475 #define p_ll                    p11
 476 #define p_end                   p12
 477
 478 #define MAX_MATCH               258
 479 #define MIN_MATCH                 4
 480 #define WSIZE                 32768
 481 #define MAX_DIST                WSIZE - MAX_MATCH - MIN_MATCH - 1
 482
 483 #define R_INPUT                 1
 484 #define R_LOCAL                 31
 485 #define R_OUTPUT                0
 486 #define R_ROTATING              24
 487 #define MLAT                    3
 488 #define SHLAT                   2
 489
 490 #define mova                    mov
 491 #define movi0                   mov
 492 #define cgtu                    cmp.gt.unc
 493 #define cgeu                    cmp.ge.unc
 494 #define cneu                    cmp.ne.unc
 495
 496         .global longest_match
 497         .proc longest_match
 498         .align 32
 499 longest_match:
 500 // --  Cycle: 0
 501         .prologue
 502 {.mmi
 503          alloc r2=ar.pfs,R_INPUT,R_LOCAL,R_OUTPUT,R_ROTATING
 504         .rotr scan[MLAT+2], match[MLAT+2], shscan0[SHLAT+1], \
 505               shscan1[SHLAT+1], shmatch0[SHLAT+1], shmatch1[SHLAT+1]
 506         .rotp lc[MLAT+SHLAT+2]
 507         mova s_vspec_cmatch=in0 // cur_match from input register
 508         add s_tm1=@gprel(strstart),gp // a(a(strstart))
 509 }{.mmi
 510         add s_tm3=@gprel(prev_length),gp // a(a(prev_length))
 511         add s_tm5=@ltoff(window),gp // a(a(window))
 512         add s_tm6=@ltoff(prev),gp // a(a(prev))
 513         ;;
 514 }{.mmb  //  Cycle: 1
 515         ld4 s_vstrstart=[s_tm1] // strstart
 516         ld4 s_vbestlen=[s_tm3] // best_len = prev_length
 517         brp.loop.imp .cmploop,.cmploop+48
 518 }{.mli
 519         add s_tm2=@gprel(max_chain_length),gp // a(a(max_chain_length))
 520         movl s_wmask=WSIZE-1
 521         ;;
 522 }{.mmi  //  Cycle: 2
 523         ld8 s_aprev=[s_tm6] // a(prev)
 524         ld8 s_awindow=[s_tm5] // a(window)
 525         .save pr, s_prsave
 526         movi0 s_prsave=pr // save predicates
 527 }{.mmi
 528         add s_tm4=@gprel(good_match),gp // a(a(good_match))
 529         add s_tm7=@ltoff(nice_match),gp // a(a(nice_match))
 530         add s_tm8=@ltoff(match_start),gp // a(match_start)
 531         ;;
 532 }{.mmi  //  Cycle: 3
 533         ld8 s_anicematch=[s_tm7] // a(nice_match)
 534         ld8 s_amatchstart=[s_tm8] // a(match_start)
 535         .save ar.lc, s_lcsave
 536         movi0 s_lcsave=ar.lc // save loop count register
 537 }{.mmi
 538         .body
 539         add s_tm1=-(MAX_MATCH + MIN_MATCH),s_wmask // maxdist
 540         cmp.eq p_ll,p0=r0,r0 // parallel compare initialized as 'true'
 541         mova s_vcurmatch=s_vspec_cmatch
 542         ;;
 543 }{.mmi  //  Cycle: 4
 544         ld4 s_vchainlen=[s_tm2] // chain_length=max_chain_length
 545         ld4 s_tm4=[s_tm4] // v(good_match)
 546         add s_ascan=s_awindow,s_vstrstart // scan=window + strstart
 547 }{.mmi
 548         sub s_vlimit=s_vstrstart, s_tm1 // limit=strstart - MAX_DIST
 549         add s_amatch=s_awindow,s_vspec_cmatch // match=window + cur_match
 550         and s_vspec_cmatch =s_vspec_cmatch,s_wmask
 551         ;;
 552 }{.mmi  //  Cycle: 5
 553         add s_amatblen=s_amatch,s_vbestlen //
 554         cneu p_bn2,p0=2,s_vbestlen // set if bestlen != 2
 555         add s_ascanend=s_ascan,s_vbestlen // compute a(scan) + best_len
 556 }{.mmi
 557         ld1 s_vscan0=[s_ascan],1 // NB: s_ascan++
 558         ld1 s_vmatch0=[s_amatch],1
 559         cgtu p0,p_no=s_vlimit,r0 // is result positive ?
 560         ;;
 561 }{.mmi  //  Cycle: 6
 562         ld1.nt1 s_vscan1=[s_ascan],2 // NB: s_ascan+3 in total
 563         ld1.nt1 s_vmatch1=[s_amatch],2
 564         add s_awinbest=s_awindow,s_vbestlen //
 565         ;;
 566 }{.mmi  //  Cycle: 7
 567         ld1.nt1 s_vscanend=[s_ascanend],-1 // scan_end=scan[best_len]
 568         ld1.nt1 s_vmatbst=[s_amatblen],-1
 569 (p_no)  mova s_vlimit=r0
 570         ;;
 571 }{.mmi  //  Cycle: 8
 572 (p_bn2) ld1.nt1 s_vscanend1=[s_ascanend],1 // scan_end1=scan[best_len-1]
 573 (p_bn2) ld1.nt1 s_vmatbst1=[s_amatblen]
 574         shladd s_vspec_cmatch =s_vspec_cmatch,1,s_aprev
 575 }{.mmi
 576         cgeu p_shf,p0=s_vbestlen,s_tm4 // is (prev_length >= good_match) ?
 577         ;;
 578 }{.mmi  //  Cycle: 9
 579         ld1.nt1 s_vscan3=[s_ascan]
 580         ld2.nt1 s_vspec_cmatch=[s_vspec_cmatch]
 581         mova    s_vlen=3
 582 }{.mmi
 583 (p_shf) shr.u s_vchainlen=s_vchainlen,2 // (cur_len) >> 2
 584         ;;
 585 }{.mmi  //  Cycle: 10
 586         ld1.nt1 s_vmatch3=[s_amatch]
 587         // p_ll switched on as soon as we get a mismatch:
 588         cmp.eq.and p_ll,p0=s_vmatch0,s_vscan0
 589         cmp.eq.and p_ll,p0=s_vmatbst,s_vscanend
 590 }{.mib
 591         cmp.eq.and p_ll,p0=s_vmatch1,s_vscan1
 592 (p_bn2) cmp.eq.and p_ll,p0=s_vmatbst1,s_vscanend1
 593 (p_ll)  br.cond.dpnt.many .test_more
 594         ;;
 595 }
 596
 597 .next_iter:
 598 {.mmi   // Cycle 0
 599         add s_amatch=s_awindow,s_vspec_cmatch   // match=window + cur_match
 600         mov s_vcurmatch=s_vspec_cmatch          // current value
 601         add s_vchainlen=-1,s_vchainlen          // --chain_length
 602 }{.mib
 603         cmp.le.unc p_end,p0=s_vspec_cmatch,s_vlimit
 604         and s_vspec_cmatch=s_vspec_cmatch,s_wmask
 605 (p_end) br.cond.dptk.many .terminate
 606         ;;
 607 }{.mmi  // Cycle 1
 608         ld1 s_vmatch0=[s_amatch],1              // load match[0]
 609         // compute prev[cur_match]:
 610         shladd s_vspec_cmatch=s_vspec_cmatch,1,s_aprev
 611         cmp.eq.unc p_end,p0=s_vchainlen,r0
 612 } {.mib
 613         nop.m 0
 614         add s_amatblen=s_awinbest,s_vcurmatch   // match=window + cur_match
 615 (p_end) br.cond.dptk.many .terminate
 616         ;;
 617 }{.mmi  // Cycle 2 (short)
 618         ld2.nt1 s_vspec_cmatch=[s_vspec_cmatch]         // get next cur_match
 619         ;;
 620 }{.mmi  // Cycle 3 (short)
 621         ld1.nt1 s_vmatbst=[s_amatblen],-1       // load match[best_len]
 622         cmp.ne.unc p_ll,p0=r0,r0     // parallel compare initialized as 'false'
 623         ;;
 624 }{.mmi  // Cycle 4 (short)
 625         // load match[1] - - note: match += 3 (in total):
 626         ld1.nt1 s_vmatch1=[s_amatch],2
 627         ;;
 628         // Cycle 5  (short)
 629 (p_bn2) ld1.nt1 s_vmatbst1=[s_amatblen]         // load match[best_len-1]
 630 }{.mib  // Here we (MOST LIKELY) pay a L2-fetch stall
 631         // p_ll switched on as soon as we get a mismatch:
 632         cmp.ne.or p_ll,p0=s_vmatch0,s_vscan0
 633         cmp.ne.or p_ll,p0=s_vmatbst,s_vscanend
 634 (p_ll)  br.cond.dptk.many .next_iter
 635         ;;
 636 }{.mmi  // Cycle 6
 637         ld1.nt1 s_vmatch3=[s_amatch]
 638         mova s_vlen=3
 639         nop.i 0
 640 }{.mib
 641         cmp.ne.or p_ll,p0=s_vmatch1,s_vscan1
 642 (p_bn2) cmp.ne.or p_ll,p0=s_vmatbst1,s_vscanend1
 643 (p_ll)  br.cond.dptk.many .next_iter
 644         ;;
 645 }
 646
 647 // We have passed the first hurdle - Are there additional matches ???
 648
 649 .test_more:
 650 {.mmi   // Cycle 0
 651         and s_tm3=7,s_ascan                     // get byte offset
 652         and s_tm4=7,s_amatch                    // get byte offset
 653         movi0 ar.ec=MLAT+SHLAT+2                // NB: One trip more than usual
 654 }{.mib
 655         cmp.ne.unc p_no,p0=s_vscan3,s_vmatch3   // does not next one differ?
 656 (p_no)  br.cond.dptk.many .only3
 657         ;;
 658 }{.mmi  // Cycle 1
 659         and s_tm1=-8,s_ascan    // get aligned address
 660         shladd s_tm3=s_tm3,3,r0
 661         movi0 ar.lc=31          // 32 times around the loop (8B at a time)
 662 }{.mib
 663         and s_tm2=-8,s_amatch                   // get aligned address
 664         shladd s_tm4=s_tm4,3,r0
 665         nop.b 0
 666         ;;
 667 }{.mmi  // Cycle 2
 668         ld8.nt1 scan[1]=[s_tm1],8                       // load first chunk
 669         sub s_tm5=64,s_tm3                              // 64 - amount
 670         movi0 pr.rot=1<<16
 671 }{.mmi
 672         ld8.nt1 match[1]=[s_tm2],8      // load first chunk
 673         sub s_tm6=64,s_tm4              // 64 - amount
 674         add s_vlen=-8,s_vlen            // will be updated at least once
 675         ;;
 676 }
 677         .align 32
 678 .cmploop:
 679 {.mmi   // Cycle 0
 680 (lc[0])                 ld8 scan[0]=[s_tm1],8           // next scan chunk
 681 (lc[MLAT+SHLAT+1])      add s_vlen=8,s_vlen
 682 (lc[MLAT])              first shscan0[0]=scan[MLAT+1],s_tm3
 683 }{.mib
 684 (lc[MLAT+SHLAT+1])      cmp.ne.unc p_no,p0=s_tm7,s_tm8  // break search if !=
 685 (lc[MLAT])              first shmatch0[0]=match[MLAT+1],s_tm4
 686 (p_no)                  br.cond.dpnt.many .mismatch
 687                         ;;
 688 }{.mii  // Cycle 1
 689 (lc[0])                 ld8 match[0]=[s_tm2],8
 690                         // shift left(le) or right(be):
 691 (lc[MLAT])              second shscan1[0]=scan[MLAT],s_tm5
 692 (lc[MLAT])              second shmatch1[0]=match[MLAT],s_tm6
 693 }{.mmb
 694 (lc[MLAT+SHLAT])        or s_tm7=shscan0[SHLAT],shscan1[SHLAT]
 695 (lc[MLAT+SHLAT])        or s_tm8=shmatch0[SHLAT],shmatch1[SHLAT]
 696                         br.ctop.dptk.many .cmploop
 697                         ;;
 698 }{.mfi
 699         mov s_vlen=258
 700         nop.f 0
 701 }{.mfi
 702         nop.f 0    // realign
 703         ;;
 704 }
 705 .mismatch:
 706 {.mii   // Cycle 0 (short)
 707 (p_no)  pcmp1.eq s_tm2=s_tm7,s_tm8      // find first non-matching character
 708         nop.i 0
 709         ;;
 710         // Cycle 1 (short)
 711 (p_no)  count s_tm1=s_tm2
 712         ;;
 713 }{.mib  // Cycle 2 (short)
 714 (p_no)  add s_vlen=s_vlen,s_tm1         // effective length
 715         nop.i 0
 716         clrrrb
 717         ;;
 718 }
 719
 720 .only3:
 721 {.mib   // Cycle 0 (short)
 722         cmp.gt.unc p0,p_nbs=s_vlen,s_vbestlen           // (len > best_len) ?
 723 (p_nbs) br.cond.dpnt.many .next_iter                    // if not, re-iternate
 724         ;;
 725 }{.mmi  // Cycle 1 (short)
 726         ld4 s_tm7=[s_anicematch]                        // nice_match
 727         st4 [s_amatchstart]= s_vcurmatch
 728         add s_ascanend=s_ascan,s_vlen                   // reset with best_len
 729         ;;
 730 }{.mmi  // Cycle 2 (short)
 731         mova s_vbestlen=s_vlen
 732         add s_ascanend=-3,s_ascanend            // remember extra offset
 733         ;;
 734 }{.mmi  // Cycle 3 (short)
 735         ld1 s_vscanend=[s_ascanend],-1          // scan_end=scan[best_len]
 736         add s_awinbest=s_awindow,s_vbestlen     // update with new best_len
 737         cmp.ne.unc p_bn2,p0=2,s_vbestlen        // set if bestlen != 2
 738         ;;
 739 }{.mib  // Cycle 4 (short)
 740         // scan_end1=scan[best_len-1] NB: s_ascanend reset:
 741         ld1.nt1 s_vscanend1=[s_ascanend],1
 742         cmp.lt.unc p_nnc,p0=s_vlen,s_tm7        // compare with nice_match
 743 (p_nnc) br.cond.dptk.many .next_iter
 744         ;;
 745 }
 746 .terminate:
 747 {.mii   // Cycle 0/1
 748         nop.m 0
 749         movi0 ar.lc=s_lcsave
 750         movi0 pr=s_prsave,-1
 751 }{.mbb
 752         nop.m 0
 753         nop.b 0
 754         br.ret.sptk.many rp     // ret0 is identical to best_len
 755         ;;
 756 }
 757         .endp
 758
 759         .global match_init
 760         .proc match_init
 761 match_init:
 762         sub ret0=ret0,ret0
 763         br.ret.sptk.many rp
 764         .endp
 765
 766 # else
 767  error: this asm version is for 386 or 680x0 or ia64 only
 768 # endif /* __ia64__ */
 769 #endif /* mc68000 || mc68020 */
 770 #endif /* i386 || _I386   */