release/src/router/nettle/x86_64/serpent-encrypt.asm

   1 C nettle, low-level cryptographics library
   2 C
   3 C Copyright (C) 2011 Niels Möller
   4 C
   5 C The nettle library is free software; you can redistribute it and/or modify
   6 C it under the terms of the GNU Lesser General Public License as published by
   7 C the Free Software Foundation; either version 2.1 of the License, or (at your
   8 C option) any later version.
   9 C
  10 C The nettle library is distributed in the hope that it will be useful, but
  11 C WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12 C or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  13 C License for more details.
  14 C
  15 C You should have received a copy of the GNU Lesser General Public License
  16 C along with the nettle library; see the file COPYING.LIB.  If not, write to
  17 C the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  18 C MA 02111-1301, USA.
  19
  20 include_src(<x86_64/serpent.m4>)
  21
  22 C Register usage:
  23
  24 C Single block serpent state, two copies
  25 define(<x0>, <%eax>)
  26 define(<x1>, <%ebx>)
  27 define(<x2>, <%ebp>)
  28 define(<x3>, <%r8d>)
  29
  30 define(<y0>, <%r9d>)
  31 define(<y1>, <%r10d>)
  32 define(<y2>, <%r11d>)
  33 define(<y3>, <%r12d>)
  34
  35 C Quadruple block serpent state, two copies
  36 define(<X0>, <%xmm0>)
  37 define(<X1>, <%xmm1>)
  38 define(<X2>, <%xmm2>)
  39 define(<X3>, <%xmm3>)
  40
  41 define(<Y0>, <%xmm4>)
  42 define(<Y1>, <%xmm5>)
  43 define(<Y2>, <%xmm6>)
  44 define(<Y3>, <%xmm7>)
  45
  46 define(<MINUS1>, <%xmm8>)
  47 define(<T0>, <%xmm9>)
  48 define(<T1>, <%xmm10>)
  49 define(<T2>, <%xmm11>)
  50 define(<T3>, <%xmm12>)
  51
  52 C Arguments
  53 define(<CTX>, <%rdi>)
  54 define(<N>, <%rsi>)
  55 define(<DST>, <%rdx>)
  56 define(<SRC>, <%rcx>)
  57
  58 define(<CNT>, <%r13>)
  59 define(<TMP32>, <%r14d>)
  60
  61 C SBOX macros. Inputs $1 - $4 (destroyed), outputs $5 - $8
  62
  63 define(<SBOX0>, <
  64         mov     $2, $8  C y3  = x1 ^ x2
  65         xor     $3, $8
  66         mov     $1, $5  C y0  = x0 | x3
  67         or      $4, $5
  68         mov     $1, $6  C y1  = x0 ^ x1
  69         xor     $2, $6
  70         xor     $5, $8  C y3 ^= y0
  71         mov     $3, $7  C y2  = x2 | y3
  72         or      $8, $7
  73         xor     $4, $1  C x0 ^= x3
  74         and     $4, $7  C y2 &= x3
  75         xor     $3, $4  C x3 ^= x2
  76         or      $2, $3  C x2 |= x1
  77         mov     $6, $5  C y0  = y1 & x2
  78         and     $3, $5
  79         xor     $5, $7  C y2 ^= y0
  80         and     $7, $5  C y0 &= y2
  81         xor     $3, $5  C y0 ^= x2
  82         and     $1, $2  C x1 &= x0
  83         xor     $1, $5  C y0 ^= x0
  84         not     $5      C y0  = ~y0
  85         mov     $5, $6  C y1  = y0 ^ x1
  86         xor     $2, $6
  87         xor     $4, $6  C y1 ^= x3
  88 >)
  89
  90 define(<SBOX1>, <
  91         mov     $1, $6  C y1  = x0 | x3
  92         or      $4, $6
  93         mov     $3, $7  C y2  = x2 ^ x3
  94         xor     $4, $7
  95         mov     $2, $5  C y0  = ~x1
  96         not     $5
  97         mov     $1, $8  C y3  = x0 ^ x2
  98         xor     $3, $8
  99         or      $1, $5  C y0 |= x0
 100         and     $4, $8  C y3 &= x3
 101         mov     $6, $1  C x0  = y1 & y2
 102         and     $7, $1
 103         or      $2, $8  C y3 |= x1
 104         xor     $5, $7  C y2 ^= y0
 105         xor     $1, $8  C y3 ^= x0
 106         mov     $6, $1  C x0  = y1 ^ y3
 107         xor     $8, $1
 108         xor     $7, $1  C x0 ^= y2
 109         mov     $2, $6  C y1  = x1 & x3
 110         and     $4, $6
 111         xor     $1, $6  C y1 ^= x0
 112         mov     $6, $4  C x3  = y1 | y3
 113         or      $8, $4
 114         not     $8      C y3  = ~y3
 115         and     $4, $5  C y0 &= x3
 116         xor     $3, $5  C y0 ^= x2
 117 >)
 118
 119 define(<SBOX2>, <
 120         mov     $1, $7  C y2 = x1 | x2
 121         or      $3, $7
 122         mov     $1, $6
 123         xor     $2, $6
 124         mov     $4, $8
 125         xor     $7, $8
 126         mov     $6, $5
 127         xor     $8, $5
 128         or      $1, $4
 129         xor     $5, $3
 130         mov     $2, $1
 131         xor     $3, $1
 132         or      $2, $3
 133         and     $7, $1
 134         xor     $3, $8
 135         or      $8, $6
 136         xor     $1, $6
 137         mov     $8, $7
 138         xor     $6, $7
 139         xor     $2, $7
 140         not     $8
 141         xor     $4, $7
 142 >)
 143
 144 define(<SBOX3>, <
 145         mov     $1, $6
 146         xor     $3, $6
 147         mov     $1, $5
 148         or      $4, $5
 149         mov     $1, $8
 150         and     $4, $8
 151         and     $5, $6
 152         or      $2, $8
 153         mov     $1, $7
 154         and     $2, $7
 155         or      $3, $7
 156         mov     $4, $3
 157         xor     $6, $3
 158         xor     $8, $6
 159         or      $3, $1
 160         xor     $2, $3
 161         and     $4, $8
 162         xor     $8, $5
 163         mov     $7, $8
 164         xor     $3, $8
 165         xor     $5, $7
 166         or      $8, $4
 167         and     $4, $2
 168         mov     $1, $5
 169         xor     $2, $5
 170 >)
 171
 172 define(<SBOX4>, <
 173         mov     $1, $8
 174         or      $2, $8
 175         mov     $2, $7
 176         or      $3, $7
 177         xor     $1, $7
 178         and     $4, $8
 179         mov     $2, $5
 180         xor     $4, $5
 181         or      $7, $4
 182         and     $4, $1
 183         and     $3, $2
 184         xor     $8, $3
 185         xor     $7, $8
 186         or      $2, $7
 187         mov     $8, $6
 188         and     $5, $6
 189         xor     $6, $7
 190         xor     $5, $6
 191         or      $2, $6
 192         xor     $1, $6
 193         and     $4, $5
 194         xor     $3, $5
 195         not     $5
 196 >)
 197
 198 define(<SBOX5>, <
 199         mov     $2, $5
 200         or      $4, $5
 201         xor     $3, $5
 202         mov     $2, $3
 203         xor     $4, $3
 204         mov     $1, $7
 205         xor     $3, $7
 206         and     $3, $1
 207         xor     $1, $5
 208         mov     $2, $8
 209         or      $7, $8
 210         or      $5, $2
 211         not     $5
 212         or      $5, $1
 213         xor     $3, $8
 214         xor     $1, $8
 215         mov     $4, $6
 216         or      $5, $6
 217         xor     $6, $4
 218         xor     $7, $6
 219         or      $4, $7
 220         xor     $2, $7
 221 >)
 222
 223 define(<SBOX6>, <
 224         mov     $1, $5
 225         xor     $4, $5
 226         mov     $1, $6
 227         and     $4, $6
 228         mov     $1, $7
 229         or      $3, $7
 230         or      $2, $4
 231         xor     $3, $4
 232         xor     $2, $1
 233         mov     $2, $8
 234         or      $3, $8
 235         xor     $2, $3
 236         and     $5, $8
 237         xor     $3, $6
 238         not     $6
 239         and     $6, $5
 240         and     $6, $2
 241         xor     $8, $2
 242         xor     $4, $8
 243         xor     $2, $7
 244         not     $7
 245         xor     $7, $5
 246         xor     $1, $5
 247 >)
 248
 249 define(<SBOX7>, <
 250         mov     $1, $5
 251         and     $3, $5
 252         mov     $2, $8
 253         or      $5, $8  C t04
 254         xor     $3, $8
 255         mov     $4, $6
 256         not     $6      C t02
 257         and     $1, $6
 258         xor     $6, $8
 259         mov     $3, $6
 260         or      $8, $6
 261         xor     $1, $6
 262         mov     $1, $7
 263         and     $2, $7
 264         xor     $7, $3
 265         or      $4, $7
 266         xor     $7, $6
 267         mov     $2, $7
 268         or      $5, $7  C t04
 269         and     $8, $7
 270         xor     $6, $2
 271         or      $2, $7
 272         xor     $1, $7
 273         xor     $6, $5
 274         not     $4      C t02
 275         or      $4, $5
 276         xor     $3, $5
 277 >)
 278
 279 define(<LT>, <
 280         rol     <$>13, $1
 281         rol     <$>3, $3
 282         xor     $1, $2
 283         xor     $3, $2
 284         mov     $1, TMP32
 285         shl     <$>3, TMP32
 286         xor     $3, $4
 287         xor     TMP32, $4
 288         rol     $2
 289         rol     <$>7, $4
 290         xor     $2, $1
 291         xor     $4, $1
 292         mov     $2, TMP32
 293         shl     <$>7, TMP32
 294         xor     $4, $3
 295         xor     TMP32, $3
 296         rol     <$>5, $1
 297         rol     <$>22, $3
 298 >)
 299
 300 C Parallel operation on four blocks at a time.
 301
 302 C pnot instruction is missing. For lack of a spare register, XOR with
 303 C constant in memory.
 304
 305 define(<PNOT>, <
 306         pxor    MINUS1, $1
 307 >)
 308
 309 define(<WSBOX0>, <
 310         movdqa  $2, $8  C y3  = x1 ^ x2
 311         pxor    $3, $8
 312         movdqa  $1, $5  C y0  = x0 | x3
 313         por     $4, $5
 314         movdqa  $1, $6  C y1  = x0 ^ x1
 315         pxor    $2, $6
 316         pxor    $5, $8  C y3 ^= y0
 317         movdqa  $3, $7  C y2  = x2 | y3
 318         por     $8, $7
 319         pxor    $4, $1  C x0 ^= x3
 320         pand    $4, $7  C y2 &= x3
 321         pxor    $3, $4  C x3 ^= x2
 322         por     $2, $3  C x2 |= x1
 323         movdqa  $6, $5  C y0  = y1 & x2
 324         pand    $3, $5
 325         pxor    $5, $7  C y2 ^= y0
 326         pand    $7, $5  C y0 &= y2
 327         pxor    $3, $5  C y0 ^= x2
 328         pand    $1, $2  C x1 &= x0
 329         pxor    $1, $5  C y0 ^= x0
 330         PNOT($5)        C y0  = ~y0
 331         movdqa  $5, $6  C y1  = y0 ^ x1
 332         pxor    $2, $6
 333         pxor    $4, $6  C y1 ^= x3
 334 >)
 335
 336 define(<WSBOX1>, <
 337         movdqa  $1, $6  C y1  = x0 | x3
 338         por     $4, $6
 339         movdqa  $3, $7  C y2  = x2 ^ x3
 340         pxor    $4, $7
 341         movdqa  $2, $5  C y0  = ~x1
 342         PNOT($5)
 343         movdqa  $1, $8  C y3  = x0 ^ x2
 344         pxor    $3, $8
 345         por     $1, $5  C y0 |= x0
 346         pand    $4, $8  C y3 &= x3
 347         movdqa  $6, $1  C x0  = y1 & y2
 348         pand    $7, $1
 349         por     $2, $8  C y3 |= x1
 350         pxor    $5, $7  C y2 ^= y0
 351         pxor    $1, $8  C y3 ^= x0
 352         movdqa  $6, $1  C x0  = y1 ^ y3
 353         pxor    $8, $1
 354         pxor    $7, $1  C x0 ^= y2
 355         movdqa  $2, $6  C y1  = x1 & x3
 356         pand    $4, $6
 357         pxor    $1, $6  C y1 ^= x0
 358         movdqa  $6, $4  C x3  = y1 | y3
 359         por     $8, $4
 360         PNOT($8)        C y3  = ~y3
 361         pand    $4, $5  C y0 &= x3
 362         pxor    $3, $5  C y0 ^= x2
 363 >)
 364
 365 define(<WSBOX2>, <
 366         movdqa  $1, $7  C y2 = x1 | x2
 367         por     $3, $7
 368         movdqa  $1, $6
 369         pxor    $2, $6
 370         movdqa  $4, $8
 371         pxor    $7, $8
 372         movdqa  $6, $5
 373         pxor    $8, $5
 374         por     $1, $4
 375         pxor    $5, $3
 376         movdqa  $2, $1
 377         pxor    $3, $1
 378         por     $2, $3
 379         pand    $7, $1
 380         pxor    $3, $8
 381         por     $8, $6
 382         pxor    $1, $6
 383         movdqa  $8, $7
 384         pxor    $6, $7
 385         pxor    $2, $7
 386         PNOT($8)
 387         pxor    $4, $7
 388 >)
 389
 390 define(<WSBOX3>, <
 391         movdqa  $1, $6
 392         pxor    $3, $6
 393         movdqa  $1, $5
 394         por     $4, $5
 395         movdqa  $1, $8
 396         pand    $4, $8
 397         pand    $5, $6
 398         por     $2, $8
 399         movdqa  $1, $7
 400         pand    $2, $7
 401         por     $3, $7
 402         movdqa  $4, $3
 403         pxor    $6, $3
 404         pxor    $8, $6
 405         por     $3, $1
 406         pxor    $2, $3
 407         pand    $4, $8
 408         pxor    $8, $5
 409         movdqa  $7, $8
 410         pxor    $3, $8
 411         pxor    $5, $7
 412         por     $8, $4
 413         pand    $4, $2
 414         movdqa  $1, $5
 415         pxor    $2, $5
 416 >)
 417
 418 define(<WSBOX4>, <
 419         movdqa  $1, $8
 420         por     $2, $8
 421         movdqa  $2, $7
 422         por     $3, $7
 423         pxor    $1, $7
 424         pand    $4, $8
 425         movdqa  $2, $5
 426         pxor    $4, $5
 427         por     $7, $4
 428         pand    $4, $1
 429         pand    $3, $2
 430         pxor    $8, $3
 431         pxor    $7, $8
 432         por     $2, $7
 433         movdqa  $8, $6
 434         pand    $5, $6
 435         pxor    $6, $7
 436         pxor    $5, $6
 437         por     $2, $6
 438         pxor    $1, $6
 439         pand    $4, $5
 440         pxor    $3, $5
 441         PNOT($5)
 442 >)
 443
 444 define(<WSBOX5>, <
 445         movdqa  $2, $5
 446         por     $4, $5
 447         pxor    $3, $5
 448         movdqa  $2, $3
 449         pxor    $4, $3
 450         movdqa  $1, $7
 451         pxor    $3, $7
 452         pand    $3, $1
 453         pxor    $1, $5
 454         movdqa  $2, $8
 455         por     $7, $8
 456         por     $5, $2
 457         PNOT($5)
 458         por     $5, $1
 459         pxor    $3, $8
 460         pxor    $1, $8
 461         movdqa  $4, $6
 462         por     $5, $6
 463         pxor    $6, $4
 464         pxor    $7, $6
 465         por     $4, $7
 466         pxor    $2, $7
 467 >)
 468
 469 define(<WSBOX6>, <
 470         movdqa  $1, $5
 471         pxor    $4, $5
 472         movdqa  $1, $6
 473         pand    $4, $6
 474         movdqa  $1, $7
 475         por     $3, $7
 476         por     $2, $4
 477         pxor    $3, $4
 478         pxor    $2, $1
 479         movdqa  $2, $8
 480         por     $3, $8
 481         pxor    $2, $3
 482         pand    $5, $8
 483         pxor    $3, $6
 484         PNOT($6)
 485         pand    $6, $5
 486         pand    $6, $2
 487         pxor    $8, $2
 488         pxor    $4, $8
 489         pxor    $2, $7
 490         PNOT($7)
 491         pxor    $7, $5
 492         pxor    $1, $5
 493 >)
 494
 495 define(<WSBOX7>, <
 496         movdqa  $1, $5
 497         pand    $3, $5
 498         movdqa  $2, $8
 499         por     $5, $8  C t04
 500         pxor    $3, $8
 501         movdqa  $4, $6
 502         pandn   $1, $6  C t02 implicit
 503         pxor    $6, $8
 504         movdqa  $3, $6
 505         por     $8, $6
 506         pxor    $1, $6
 507         movdqa  $1, $7
 508         pand    $2, $7
 509         pxor    $7, $3
 510         por     $4, $7
 511         pxor    $7, $6
 512         movdqa  $2, $7
 513         por     $5, $7  C t04
 514         pand    $8, $7
 515         pxor    $6, $2
 516         por     $2, $7
 517         pxor    $1, $7
 518         pxor    $6, $5
 519         PNOT($4)        C t02
 520         por     $4, $5
 521         pxor    $3, $5
 522 >)
 523
 524 C WLT(x0, x1, x2, x3)
 525 define(<WLT>, <
 526         WROL(13, $1)
 527         WROL(3, $3)
 528         pxor    $1, $2
 529         pxor    $3, $2
 530         movdqa  $1, T0
 531         pslld   <$>3, T0
 532         pxor    $3, $4
 533         pxor    T0, $4
 534         WROL(1, $2)
 535         WROL(7, $4)
 536         pxor    $2, $1
 537         pxor    $4, $1
 538         movdqa  $2, T0
 539         pslld   <$>7, T0
 540         pxor    $4, $3
 541         pxor    T0, $3
 542         WROL(5, $1)
 543         WROL(22, $3)
 544 >)
 545
 546         .file "serpent-encrypt.asm"
 547
 548         C serpent_encrypt(struct serpent_context *ctx,
 549         C                 unsigned length, uint8_t *dst,
 550         C                 const uint8_t *src)
 551         .text
 552         ALIGN(16)
 553 PROLOGUE(nettle_serpent_encrypt)
 554         C save all registers that need to be saved
 555         W64_ENTRY(4, 13)
 556         push    %rbx
 557         push    %rbp
 558         push    %r12
 559         push    %r13
 560         push    %r14
 561
 562         lea     (SRC, N), SRC
 563         lea     (DST, N), DST
 564         neg     N
 565         jz      .Lend
 566
 567         C Point at the final subkey.
 568         lea     512(CTX), CTX
 569
 570         cmp     $-64, N
 571         ja      .Lblock_loop
 572
 573         pcmpeqd MINUS1, MINUS1
 574
 575 .Lwblock_loop:
 576         movups  (SRC, N), X0
 577         movups  16(SRC, N), X1
 578         movups  32(SRC, N), X2
 579         movups  48(SRC, N), X3
 580
 581         WTRANSPOSE(X0, X1, X2, X3)
 582
 583         mov     $-512, CNT
 584         jmp     .Lwround_start
 585
 586         ALIGN(16)
 587 .Lwround_loop:
 588         WLT(X0,X1,X2,X3)
 589 .Lwround_start:
 590         WKEYXOR(, X0,X1,X2,X3)
 591         WSBOX0(X0,X1,X2,X3, Y0,Y1,Y2,Y3)
 592         WLT(Y0,Y1,Y2,Y3)
 593
 594         WKEYXOR(16, Y0,Y1,Y2,Y3)
 595         WSBOX1(Y0,Y1,Y2,Y3, X0,X1,X2,X3)
 596         WLT(X0,X1,X2,X3)
 597
 598         WKEYXOR(32, X0,X1,X2,X3)
 599         WSBOX2(X0,X1,X2,X3, Y0,Y1,Y2,Y3)
 600         WLT(Y0,Y1,Y2,Y3)
 601
 602         WKEYXOR(48, Y0,Y1,Y2,Y3)
 603         WSBOX3(Y0,Y1,Y2,Y3, X0,X1,X2,X3)
 604         WLT(X0,X1,X2,X3)
 605
 606         WKEYXOR(64, X0,X1,X2,X3)
 607         WSBOX4(X0,X1,X2,X3, Y0,Y1,Y2,Y3)
 608         WLT(Y0,Y1,Y2,Y3)
 609
 610         WKEYXOR(80, Y0,Y1,Y2,Y3)
 611         WSBOX5(Y0,Y1,Y2,Y3, X0,X1,X2,X3)
 612         WLT(X0,X1,X2,X3)
 613
 614         WKEYXOR(96, X0,X1,X2,X3)
 615         WSBOX6(X0,X1,X2,X3, Y0,Y1,Y2,Y3)
 616         WLT(Y0,Y1,Y2,Y3)
 617
 618         WKEYXOR(112, Y0,Y1,Y2,Y3)
 619         WSBOX7(Y0,Y1,Y2,Y3, X0,X1,X2,X3)
 620         add     $128, CNT
 621         jnz     .Lwround_loop
 622
 623         C FIXME: CNT known to be zero, no index register needed
 624         WKEYXOR(, X0,X1,X2,X3)
 625
 626         WTRANSPOSE(X0,X1,X2,X3)
 627
 628         movups  X0, (DST, N)
 629         movups  X1, 16(DST, N)
 630         movups  X2, 32(DST, N)
 631         movups  X3, 48(DST, N)
 632
 633         C FIXME: Adjust N, so we can use just jnc without an extra cmp.
 634         add     $64, N
 635         jz      .Lend
 636
 637         cmp     $-64, N
 638         jbe     .Lwblock_loop
 639
 640 C The single-block loop here is slightly slower than the double-block
 641 C loop in serpent-encrypt.c.
 642
 643 C FIXME: Should use non-sse2 code only if we have a single block left.
 644 C With two or three blocks, it should be better to do them in
 645 C parallell.
 646
 647 .Lblock_loop:
 648         movl    (SRC, N), x0
 649         movl    4(SRC, N), x1
 650         movl    8(SRC, N), x2
 651         movl    12(SRC, N), x3
 652
 653         mov     $-512, CNT
 654         jmp     .Lround_start
 655
 656         ALIGN(16)
 657 .Lround_loop:
 658         LT(x0,x1,x2,x3)
 659 .Lround_start:
 660         xor       (CTX, CNT), x0
 661         xor      4(CTX, CNT), x1
 662         xor      8(CTX, CNT), x2
 663         xor     12(CTX, CNT), x3
 664         SBOX0(x0,x1,x2,x3, y0,y1,y2,y3)
 665         LT(y0,y1,y2,y3)
 666
 667         xor     16(CTX, CNT), y0
 668         xor     20(CTX, CNT), y1
 669         xor     24(CTX, CNT), y2
 670         xor     28(CTX, CNT), y3
 671         SBOX1(y0,y1,y2,y3, x0,x1,x2,x3)
 672         LT(x0,x1,x2,x3)
 673
 674         xor     32(CTX, CNT), x0
 675         xor     36(CTX, CNT), x1
 676         xor     40(CTX, CNT), x2
 677         xor     44(CTX, CNT), x3
 678         SBOX2(x0,x1,x2,x3, y0,y1,y2,y3)
 679         LT(y0,y1,y2,y3)
 680
 681         xor     48(CTX, CNT), y0
 682         xor     52(CTX, CNT), y1
 683         xor     56(CTX, CNT), y2
 684         xor     60(CTX, CNT), y3
 685         SBOX3(y0,y1,y2,y3, x0,x1,x2,x3)
 686         LT(x0,x1,x2,x3)
 687
 688         xor     64(CTX, CNT), x0
 689         xor     68(CTX, CNT), x1
 690         xor     72(CTX, CNT), x2
 691         xor     76(CTX, CNT), x3
 692         SBOX4(x0,x1,x2,x3, y0,y1,y2,y3)
 693         LT(y0,y1,y2,y3)
 694
 695         xor     80(CTX, CNT), y0
 696         xor     84(CTX, CNT), y1
 697         xor     88(CTX, CNT), y2
 698         xor     92(CTX, CNT), y3
 699         SBOX5(y0,y1,y2,y3, x0,x1,x2,x3)
 700         LT(x0,x1,x2,x3)
 701
 702         xor     96(CTX, CNT), x0
 703         xor     100(CTX, CNT), x1
 704         xor     104(CTX, CNT), x2
 705         xor     108(CTX, CNT), x3
 706         SBOX6(x0,x1,x2,x3, y0,y1,y2,y3)
 707         LT(y0,y1,y2,y3)
 708
 709         xor     112(CTX, CNT), y0
 710         xor     116(CTX, CNT), y1
 711         xor     120(CTX, CNT), y2
 712         xor     124(CTX, CNT), y3
 713         SBOX7(y0,y1,y2,y3, x0,x1,x2,x3)
 714         add     $128, CNT
 715         jnz     .Lround_loop
 716
 717         C Apply final subkey.
 718         xor       (CTX, CNT), x0
 719         xor      4(CTX, CNT), x1
 720         xor      8(CTX, CNT), x2
 721         xor     12(CTX, CNT), x3
 722
 723         movl    x0, (DST, N)
 724         movl    x1, 4(DST, N)
 725         movl    x2, 8(DST, N)
 726         movl    x3, 12(DST, N)
 727         add     $16, N
 728         jnc     .Lblock_loop
 729
 730 .Lend:
 731         pop     %r14
 732         pop     %r13
 733         pop     %r12
 734         pop     %rbp
 735         pop     %rbx
 736         W64_EXIT(4, 13)
 737         ret