release/src-rt-6.x.4708/router/samba-3.5.8/lib/zlib/contrib/masmx64/gvmat64.asm

   1 ;uInt longest_match_x64(
   2 ;    deflate_state *s,
   3 ;    IPos cur_match);                             /* current match */
   4
   5 ; gvmat64.asm -- Asm portion of the optimized longest_match for 32 bits x86
   6 ; Copyright (C) 1995-2005 Jean-loup Gailly, Brian Raiter and Gilles Vollant.
   7 ;
   8 ; File written by Gilles Vollant, by converting to assembly the longest_match
   9 ;  from Jean-loup Gailly in deflate.c of zLib and infoZip zip.
  10 ;
  11 ;  and by taking inspiration on asm686 with masm, optimised assembly code
  12 ;        from Brian Raiter, written 1998
  13 ;
  14 ;         http://www.zlib.net
  15 ;         http://www.winimage.com/zLibDll
  16 ;         http://www.muppetlabs.com/~breadbox/software/assembly.html
  17 ;
  18 ; to compile this file for infozip Zip, I use option:
  19 ;   ml64.exe /Flgvmat64 /c /Zi /DINFOZIP gvmat64.asm
  20 ;
  21 ; to compile this file for zLib, I use option:
  22 ;   ml64.exe /Flgvmat64 /c /Zi gvmat64.asm
  23 ; Be carrefull to adapt zlib1222add below to your version of zLib
  24 ;   (if you use a version of zLib before 1.0.4 or after 1.2.2.2, change
  25 ;    value of zlib1222add later)
  26 ;
  27 ; This file compile with Microsoft Macro Assembler (x64) for AMD64
  28 ;
  29 ;   ml64.exe is given with Visual Studio 2005 and Windows 2003 server DDK
  30 ;
  31 ;   (you can get Windows 2003 server DDK with ml64 and cl for AMD64 from
  32 ;      http://www.microsoft.com/whdc/devtools/ddk/default.mspx for low price)
  33 ;
  34
  35
  36 ;uInt longest_match(s, cur_match)
  37 ;    deflate_state *s;
  38 ;    IPos cur_match;                             /* current match */
  39 .code
  40 longest_match PROC
  41
  42
  43 ;LocalVarsSize   equ 88
  44  LocalVarsSize   equ 72
  45
  46 ; register used : rax,rbx,rcx,rdx,rsi,rdi,r8,r9,r10,r11,r12
  47 ; free register :  r14,r15
  48 ; register can be saved : rsp
  49
  50  chainlenwmask   equ  rsp + 8 - LocalVarsSize    ; high word: current chain len
  51                                                  ; low word: s->wmask
  52 ;window          equ  rsp + xx - LocalVarsSize   ; local copy of s->window ; stored in r10
  53 ;windowbestlen   equ  rsp + xx - LocalVarsSize   ; s->window + bestlen , use r10+r11
  54 ;scanstart       equ  rsp + xx - LocalVarsSize   ; first two bytes of string ; stored in r12w
  55 ;scanend         equ  rsp + xx - LocalVarsSize   ; last two bytes of string use ebx
  56 ;scanalign       equ  rsp + xx - LocalVarsSize   ; dword-misalignment of string r13
  57 ;bestlen         equ  rsp + xx - LocalVarsSize   ; size of best match so far -> r11d
  58 ;scan            equ  rsp + xx - LocalVarsSize   ; ptr to string wanting match -> r9
  59 IFDEF INFOZIP
  60 ELSE
  61  nicematch       equ  (rsp + 16 - LocalVarsSize) ; a good enough match size
  62 ENDIF
  63
  64 save_rdi        equ  rsp + 24 - LocalVarsSize
  65 save_rsi        equ  rsp + 32 - LocalVarsSize
  66 save_rbx        equ  rsp + 40 - LocalVarsSize
  67 save_rbp        equ  rsp + 48 - LocalVarsSize
  68 save_r12        equ  rsp + 56 - LocalVarsSize
  69 save_r13        equ  rsp + 64 - LocalVarsSize
  70 ;save_r14        equ  rsp + 72 - LocalVarsSize
  71 ;save_r15        equ  rsp + 80 - LocalVarsSize
  72
  73
  74
  75 ;  all the +4 offsets are due to the addition of pending_buf_size (in zlib
  76 ;  in the deflate_state structure since the asm code was first written
  77 ;  (if you compile with zlib 1.0.4 or older, remove the +4).
  78 ;  Note : these value are good with a 8 bytes boundary pack structure
  79
  80
  81     MAX_MATCH           equ     258
  82     MIN_MATCH           equ     3
  83     MIN_LOOKAHEAD       equ     (MAX_MATCH+MIN_MATCH+1)
  84
  85
  86 ;;; Offsets for fields in the deflate_state structure. These numbers
  87 ;;; are calculated from the definition of deflate_state, with the
  88 ;;; assumption that the compiler will dword-align the fields. (Thus,
  89 ;;; changing the definition of deflate_state could easily cause this
  90 ;;; program to crash horribly, without so much as a warning at
  91 ;;; compile time. Sigh.)
  92
  93 ;  all the +zlib1222add offsets are due to the addition of fields
  94 ;  in zlib in the deflate_state structure since the asm code was first written
  95 ;  (if you compile with zlib 1.0.4 or older, use "zlib1222add equ (-4)").
  96 ;  (if you compile with zlib between 1.0.5 and 1.2.2.1, use "zlib1222add equ 0").
  97 ;  if you compile with zlib 1.2.2.2 or later , use "zlib1222add equ 8").
  98
  99
 100 IFDEF INFOZIP
 101
 102 _DATA   SEGMENT
 103 COMM    window_size:DWORD
 104 ; WMask ; 7fff
 105 COMM    window:BYTE:010040H
 106 COMM    prev:WORD:08000H
 107 ; MatchLen : unused
 108 ; PrevMatch : unused
 109 COMM    strstart:DWORD
 110 COMM    match_start:DWORD
 111 ; Lookahead : ignore
 112 COMM    prev_length:DWORD ; PrevLen
 113 COMM    max_chain_length:DWORD
 114 COMM    good_match:DWORD
 115 COMM    nice_match:DWORD
 116 prev_ad equ OFFSET prev
 117 window_ad equ OFFSET window
 118 nicematch equ nice_match
 119 _DATA ENDS
 120 WMask equ 07fffh
 121
 122 ELSE
 123
 124   IFNDEF zlib1222add
 125     zlib1222add equ 8
 126   ENDIF
 127 dsWSize         equ 56+zlib1222add+(zlib1222add/2)
 128 dsWMask         equ 64+zlib1222add+(zlib1222add/2)
 129 dsWindow        equ 72+zlib1222add
 130 dsPrev          equ 88+zlib1222add
 131 dsMatchLen      equ 128+zlib1222add
 132 dsPrevMatch     equ 132+zlib1222add
 133 dsStrStart      equ 140+zlib1222add
 134 dsMatchStart    equ 144+zlib1222add
 135 dsLookahead     equ 148+zlib1222add
 136 dsPrevLen       equ 152+zlib1222add
 137 dsMaxChainLen   equ 156+zlib1222add
 138 dsGoodMatch     equ 172+zlib1222add
 139 dsNiceMatch     equ 176+zlib1222add
 140
 141 window_size     equ [ rcx + dsWSize]
 142 WMask           equ [ rcx + dsWMask]
 143 window_ad       equ [ rcx + dsWindow]
 144 prev_ad         equ [ rcx + dsPrev]
 145 strstart        equ [ rcx + dsStrStart]
 146 match_start     equ [ rcx + dsMatchStart]
 147 Lookahead       equ [ rcx + dsLookahead] ; 0ffffffffh on infozip
 148 prev_length     equ [ rcx + dsPrevLen]
 149 max_chain_length equ [ rcx + dsMaxChainLen]
 150 good_match      equ [ rcx + dsGoodMatch]
 151 nice_match      equ [ rcx + dsNiceMatch]
 152 ENDIF
 153
 154 ; parameter 1 in r8(deflate state s), param 2 in rdx (cur match)
 155
 156 ; see http://weblogs.asp.net/oldnewthing/archive/2004/01/14/58579.aspx and
 157 ; http://msdn.microsoft.com/library/en-us/kmarch/hh/kmarch/64bitAMD_8e951dd2-ee77-4728-8702-55ce4b5dd24a.xml.asp
 158 ;
 159 ; All registers must be preserved across the call, except for
 160 ;   rax, rcx, rdx, r8, r9, r10, and r11, which are scratch.
 161
 162
 163
 164 ;;; Save registers that the compiler may be using, and adjust esp to
 165 ;;; make room for our stack frame.
 166
 167
 168 ;;; Retrieve the function arguments. r8d will hold cur_match
 169 ;;; throughout the entire function. edx will hold the pointer to the
 170 ;;; deflate_state structure during the function's setup (before
 171 ;;; entering the main loop.
 172
 173 ; parameter 1 in rcx (deflate_state* s), param 2 in edx -> r8 (cur match)
 174
 175 ; this clear high 32 bits of r8, which can be garbage in both r8 and rdx
 176
 177         mov [save_rdi],rdi
 178         mov [save_rsi],rsi
 179         mov [save_rbx],rbx
 180         mov [save_rbp],rbp
 181 IFDEF INFOZIP
 182         mov r8d,ecx
 183 ELSE
 184         mov r8d,edx
 185 ENDIF
 186         mov [save_r12],r12
 187         mov [save_r13],r13
 188 ;        mov [save_r14],r14
 189 ;        mov [save_r15],r15
 190
 191
 192 ;;; uInt wmask = s->w_mask;
 193 ;;; unsigned chain_length = s->max_chain_length;
 194 ;;; if (s->prev_length >= s->good_match) {
 195 ;;;     chain_length >>= 2;
 196 ;;; }
 197
 198         mov edi, prev_length
 199         mov esi, good_match
 200         mov eax, WMask
 201         mov ebx, max_chain_length
 202         cmp edi, esi
 203         jl  LastMatchGood
 204         shr ebx, 2
 205 LastMatchGood:
 206
 207 ;;; chainlen is decremented once beforehand so that the function can
 208 ;;; use the sign flag instead of the zero flag for the exit test.
 209 ;;; It is then shifted into the high word, to make room for the wmask
 210 ;;; value, which it will always accompany.
 211
 212         dec ebx
 213         shl ebx, 16
 214         or  ebx, eax
 215
 216 ;;; on zlib only
 217 ;;; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
 218
 219 IFDEF INFOZIP
 220         mov [chainlenwmask], ebx
 221 ; on infozip nice_match = [nice_match]
 222 ELSE
 223         mov eax, nice_match
 224         mov [chainlenwmask], ebx
 225         mov r10d, Lookahead
 226         cmp r10d, eax
 227         cmovnl r10d, eax
 228         mov [nicematch],r10d
 229 ENDIF
 230
 231 ;;; register Bytef *scan = s->window + s->strstart;
 232         mov r10, window_ad
 233         mov ebp, strstart
 234         lea r13, [r10 + rbp]
 235
 236 ;;; Determine how many bytes the scan ptr is off from being
 237 ;;; dword-aligned.
 238
 239          mov r9,r13
 240          neg r13
 241          and r13,3
 242
 243 ;;; IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
 244 ;;;     s->strstart - (IPos)MAX_DIST(s) : NIL;
 245 IFDEF INFOZIP
 246         mov eax,07efah ; MAX_DIST = (WSIZE-MIN_LOOKAHEAD) (0x8000-(3+8+1))
 247 ELSE
 248         mov eax, window_size
 249         sub eax, MIN_LOOKAHEAD
 250 ENDIF
 251         xor edi,edi
 252         sub ebp, eax
 253
 254         mov r11d, prev_length
 255
 256         cmovng ebp,edi
 257
 258 ;;; int best_len = s->prev_length;
 259
 260
 261 ;;; Store the sum of s->window + best_len in esi locally, and in esi.
 262
 263        lea  rsi,[r10+r11]
 264
 265 ;;; register ush scan_start = *(ushf*)scan;
 266 ;;; register ush scan_end   = *(ushf*)(scan+best_len-1);
 267 ;;; Posf *prev = s->prev;
 268
 269         movzx r12d,word ptr [r9]
 270         movzx ebx, word ptr [r9 + r11 - 1]
 271
 272         mov rdi, prev_ad
 273
 274 ;;; Jump into the main loop.
 275
 276         mov edx, [chainlenwmask]
 277
 278         cmp bx,word ptr [rsi + r8 - 1]
 279         jz  LookupLoopIsZero
 280
 281 LookupLoop1:
 282         and r8d, edx
 283
 284         movzx   r8d, word ptr [rdi + r8*2]
 285         cmp r8d, ebp
 286         jbe LeaveNow
 287         sub edx, 00010000h
 288         js  LeaveNow
 289
 290 LoopEntry1:
 291         cmp bx,word ptr [rsi + r8 - 1]
 292         jz  LookupLoopIsZero
 293
 294 LookupLoop2:
 295         and r8d, edx
 296
 297         movzx   r8d, word ptr [rdi + r8*2]
 298         cmp r8d, ebp
 299         jbe LeaveNow
 300         sub edx, 00010000h
 301         js  LeaveNow
 302
 303 LoopEntry2:
 304         cmp bx,word ptr [rsi + r8 - 1]
 305         jz  LookupLoopIsZero
 306
 307 LookupLoop4:
 308         and r8d, edx
 309
 310         movzx   r8d, word ptr [rdi + r8*2]
 311         cmp r8d, ebp
 312         jbe LeaveNow
 313         sub edx, 00010000h
 314         js  LeaveNow
 315
 316 LoopEntry4:
 317
 318         cmp bx,word ptr [rsi + r8 - 1]
 319         jnz LookupLoop1
 320         jmp LookupLoopIsZero
 321
 322
 323 ;;; do {
 324 ;;;     match = s->window + cur_match;
 325 ;;;     if (*(ushf*)(match+best_len-1) != scan_end ||
 326 ;;;         *(ushf*)match != scan_start) continue;
 327 ;;;     [...]
 328 ;;; } while ((cur_match = prev[cur_match & wmask]) > limit
 329 ;;;          && --chain_length != 0);
 330 ;;;
 331 ;;; Here is the inner loop of the function. The function will spend the
 332 ;;; majority of its time in this loop, and majority of that time will
 333 ;;; be spent in the first ten instructions.
 334 ;;;
 335 ;;; Within this loop:
 336 ;;; ebx = scanend
 337 ;;; r8d = curmatch
 338 ;;; edx = chainlenwmask - i.e., ((chainlen << 16) | wmask)
 339 ;;; esi = windowbestlen - i.e., (window + bestlen)
 340 ;;; edi = prev
 341 ;;; ebp = limit
 342
 343 LookupLoop:
 344         and r8d, edx
 345
 346         movzx   r8d, word ptr [rdi + r8*2]
 347         cmp r8d, ebp
 348         jbe LeaveNow
 349         sub edx, 00010000h
 350         js  LeaveNow
 351
 352 LoopEntry:
 353
 354         cmp bx,word ptr [rsi + r8 - 1]
 355         jnz LookupLoop1
 356 LookupLoopIsZero:
 357         cmp     r12w, word ptr [r10 + r8]
 358         jnz LookupLoop1
 359
 360
 361 ;;; Store the current value of chainlen.
 362         mov [chainlenwmask], edx
 363
 364 ;;; Point edi to the string under scrutiny, and esi to the string we
 365 ;;; are hoping to match it up with. In actuality, esi and edi are
 366 ;;; both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and edx is
 367 ;;; initialized to -(MAX_MATCH_8 - scanalign).
 368
 369         lea rsi,[r8+r10]
 370         mov rdx, 0fffffffffffffef8h; -(MAX_MATCH_8)
 371         lea rsi, [rsi + r13 + 0108h] ;MAX_MATCH_8]
 372         lea rdi, [r9 + r13 + 0108h] ;MAX_MATCH_8]
 373
 374         prefetcht1 [rsi+rdx]
 375         prefetcht1 [rdi+rdx]
 376
 377
 378 ;;; Test the strings for equality, 8 bytes at a time. At the end,
 379 ;;; adjust rdx so that it is offset to the exact byte that mismatched.
 380 ;;;
 381 ;;; We already know at this point that the first three bytes of the
 382 ;;; strings match each other, and they can be safely passed over before
 383 ;;; starting the compare loop. So what this code does is skip over 0-3
 384 ;;; bytes, as much as necessary in order to dword-align the edi
 385 ;;; pointer. (rsi will still be misaligned three times out of four.)
 386 ;;;
 387 ;;; It should be confessed that this loop usually does not represent
 388 ;;; much of the total running time. Replacing it with a more
 389 ;;; straightforward "rep cmpsb" would not drastically degrade
 390 ;;; performance.
 391
 392
 393 LoopCmps:
 394         mov rax, [rsi + rdx]
 395         xor rax, [rdi + rdx]
 396         jnz LeaveLoopCmps
 397
 398         mov rax, [rsi + rdx + 8]
 399         xor rax, [rdi + rdx + 8]
 400         jnz LeaveLoopCmps8
 401
 402
 403         mov rax, [rsi + rdx + 8+8]
 404         xor rax, [rdi + rdx + 8+8]
 405         jnz LeaveLoopCmps16
 406
 407         add rdx,8+8+8
 408
 409         jmp short LoopCmps
 410 LeaveLoopCmps16: add rdx,8
 411 LeaveLoopCmps8: add rdx,8
 412 LeaveLoopCmps:
 413
 414         test    eax, 0000FFFFh
 415         jnz LenLower
 416
 417         test eax,0ffffffffh
 418
 419         jnz LenLower32
 420
 421         add rdx,4
 422         shr rax,32
 423         or ax,ax
 424         jnz LenLower
 425
 426 LenLower32:
 427         shr eax,16
 428         add rdx,2
 429 LenLower:   sub al, 1
 430         adc rdx, 0
 431 ;;; Calculate the length of the match. If it is longer than MAX_MATCH,
 432 ;;; then automatically accept it as the best possible match and leave.
 433
 434         lea rax, [rdi + rdx]
 435         sub rax, r9
 436         cmp eax, MAX_MATCH
 437         jge LenMaximum
 438
 439 ;;; If the length of the match is not longer than the best match we
 440 ;;; have so far, then forget it and return to the lookup loop.
 441 ;///////////////////////////////////
 442
 443         cmp eax, r11d
 444         jg  LongerMatch
 445
 446         lea rsi,[r10+r11]
 447
 448         mov rdi, prev_ad
 449         mov edx, [chainlenwmask]
 450         jmp LookupLoop
 451
 452 ;;;         s->match_start = cur_match;
 453 ;;;         best_len = len;
 454 ;;;         if (len >= nice_match) break;
 455 ;;;         scan_end = *(ushf*)(scan+best_len-1);
 456
 457 LongerMatch:
 458         mov r11d, eax
 459         mov match_start, r8d
 460         cmp eax, [nicematch]
 461         jge LeaveNow
 462
 463         lea rsi,[r10+rax]
 464
 465         movzx   ebx, word ptr [r9 + rax - 1]
 466         mov rdi, prev_ad
 467         mov edx, [chainlenwmask]
 468         jmp LookupLoop
 469
 470 ;;; Accept the current string, with the maximum possible length.
 471
 472 LenMaximum:
 473         mov r11d,MAX_MATCH
 474         mov match_start, r8d
 475
 476 ;;; if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
 477 ;;; return s->lookahead;
 478
 479 LeaveNow:
 480 IFDEF INFOZIP
 481         mov eax,r11d
 482 ELSE
 483         mov eax, Lookahead
 484         cmp r11d, eax
 485         cmovng eax, r11d
 486 ENDIF
 487
 488 ;;; Restore the stack and return from whence we came.
 489
 490
 491         mov rsi,[save_rsi]
 492         mov rdi,[save_rdi]
 493         mov rbx,[save_rbx]
 494         mov rbp,[save_rbp]
 495         mov r12,[save_r12]
 496         mov r13,[save_r13]
 497 ;        mov r14,[save_r14]
 498 ;        mov r15,[save_r15]
 499
 500
 501         ret 0
 502 ; please don't remove this string !
 503 ; Your can freely use gvmat64 in any free or commercial app
 504 ; but it is far better don't remove the string in the binary!
 505     db     0dh,0ah,"asm686 with masm, optimised assembly code from Brian Raiter, written 1998, converted to amd 64 by Gilles Vollant 2005",0dh,0ah,0
 506 longest_match   ENDP
 507
 508 match_init PROC
 509   ret 0
 510 match_init ENDP
 511
 512
 513 END