crypto/bn/asm/x86_64-gcc.c

   1 #include "../bn_lcl.h"
   2 #if !(defined(__GNUC__) && __GNUC__>=2)
   3 # include "../bn_asm.c"         /* kind of dirty hack for Sun Studio */
   4 #else
   5 /*-
   6  * x86_64 BIGNUM accelerator version 0.1, December 2002.
   7  *
   8  * Implemented by Andy Polyakov <appro@fy.chalmers.se> for the OpenSSL
   9  * project.
  10  *
  11  * Rights for redistribution and usage in source and binary forms are
  12  * granted according to the OpenSSL license. Warranty of any kind is
  13  * disclaimed.
  14  *
  15  * Q. Version 0.1? It doesn't sound like Andy, he used to assign real
  16  *    versions, like 1.0...
  17  * A. Well, that's because this code is basically a quick-n-dirty
  18  *    proof-of-concept hack. As you can see it's implemented with
  19  *    inline assembler, which means that you're bound to GCC and that
  20  *    there might be enough room for further improvement.
  21  *
  22  * Q. Why inline assembler?
  23  * A. x86_64 features own ABI which I'm not familiar with. This is
  24  *    why I decided to let the compiler take care of subroutine
  25  *    prologue/epilogue as well as register allocation. For reference.
  26  *    Win64 implements different ABI for AMD64, different from Linux.
  27  *
  28  * Q. How much faster does it get?
  29  * A. 'apps/openssl speed rsa dsa' output with no-asm:
  30  *
  31  *                        sign    verify    sign/s verify/s
  32  *      rsa  512 bits   0.0006s   0.0001s   1683.8  18456.2
  33  *      rsa 1024 bits   0.0028s   0.0002s    356.0   6407.0
  34  *      rsa 2048 bits   0.0172s   0.0005s     58.0   1957.8
  35  *      rsa 4096 bits   0.1155s   0.0018s      8.7    555.6
  36  *                        sign    verify    sign/s verify/s
  37  *      dsa  512 bits   0.0005s   0.0006s   2100.8   1768.3
  38  *      dsa 1024 bits   0.0014s   0.0018s    692.3    559.2
  39  *      dsa 2048 bits   0.0049s   0.0061s    204.7    165.0
  40  *
  41  *    'apps/openssl speed rsa dsa' output with this module:
  42  *
  43  *                        sign    verify    sign/s verify/s
  44  *      rsa  512 bits   0.0004s   0.0000s   2767.1  33297.9
  45  *      rsa 1024 bits   0.0012s   0.0001s    867.4  14674.7
  46  *      rsa 2048 bits   0.0061s   0.0002s    164.0   5270.0
  47  *      rsa 4096 bits   0.0384s   0.0006s     26.1   1650.8
  48  *                        sign    verify    sign/s verify/s
  49  *      dsa  512 bits   0.0002s   0.0003s   4442.2   3786.3
  50  *      dsa 1024 bits   0.0005s   0.0007s   1835.1   1497.4
  51  *      dsa 2048 bits   0.0016s   0.0020s    620.4    504.6
  52  *
  53  *    For the reference. IA-32 assembler implementation performs
  54  *    very much like 64-bit code compiled with no-asm on the same
  55  *    machine.
  56  */
  57
  58 # ifdef _WIN64
  59 #  define BN_ULONG unsigned long long
  60 # else
  61 #  define BN_ULONG unsigned long
  62 # endif
  63
  64 # undef mul
  65 # undef mul_add
  66 # undef sqr
  67
  68 /*-
  69  * "m"(a), "+m"(r)      is the way to favor DirectPath µ-code;
  70  * "g"(0)               let the compiler to decide where does it
  71  *                      want to keep the value of zero;
  72  */
  73 # define mul_add(r,a,word,carry) do {   \
  74         register BN_ULONG high,low;     \
  75         asm ("mulq %3"                  \
  76                 : "=a"(low),"=d"(high)  \
  77                 : "a"(word),"m"(a)      \
  78                 : "cc");                \
  79         asm ("addq %2,%0; adcq %3,%1"   \
  80                 : "+r"(carry),"+d"(high)\
  81                 : "a"(low),"g"(0)       \
  82                 : "cc");                \
  83         asm ("addq %2,%0; adcq %3,%1"   \
  84                 : "+m"(r),"+d"(high)    \
  85                 : "r"(carry),"g"(0)     \
  86                 : "cc");                \
  87         carry=high;                     \
  88         } while (0)
  89
  90 # define mul(r,a,word,carry) do {       \
  91         register BN_ULONG high,low;     \
  92         asm ("mulq %3"                  \
  93                 : "=a"(low),"=d"(high)  \
  94                 : "a"(word),"g"(a)      \
  95                 : "cc");                \
  96         asm ("addq %2,%0; adcq %3,%1"   \
  97                 : "+r"(carry),"+d"(high)\
  98                 : "a"(low),"g"(0)       \
  99                 : "cc");                \
 100         (r)=carry, carry=high;          \
 101         } while (0)
 102
 103 # define sqr(r0,r1,a)                    \
 104         asm ("mulq %2"                  \
 105                 : "=a"(r0),"=d"(r1)     \
 106                 : "a"(a)                \
 107                 : "cc");
 108
 109 BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, int num,
 110                           BN_ULONG w)
 111 {
 112     BN_ULONG c1 = 0;
 113
 114     if (num <= 0)
 115         return (c1);
 116
 117     while (num & ~3) {
 118         mul_add(rp[0], ap[0], w, c1);
 119         mul_add(rp[1], ap[1], w, c1);
 120         mul_add(rp[2], ap[2], w, c1);
 121         mul_add(rp[3], ap[3], w, c1);
 122         ap += 4;
 123         rp += 4;
 124         num -= 4;
 125     }
 126     if (num) {
 127         mul_add(rp[0], ap[0], w, c1);
 128         if (--num == 0)
 129             return c1;
 130         mul_add(rp[1], ap[1], w, c1);
 131         if (--num == 0)
 132             return c1;
 133         mul_add(rp[2], ap[2], w, c1);
 134         return c1;
 135     }
 136
 137     return (c1);
 138 }
 139
 140 BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
 141 {
 142     BN_ULONG c1 = 0;
 143
 144     if (num <= 0)
 145         return (c1);
 146
 147     while (num & ~3) {
 148         mul(rp[0], ap[0], w, c1);
 149         mul(rp[1], ap[1], w, c1);
 150         mul(rp[2], ap[2], w, c1);
 151         mul(rp[3], ap[3], w, c1);
 152         ap += 4;
 153         rp += 4;
 154         num -= 4;
 155     }
 156     if (num) {
 157         mul(rp[0], ap[0], w, c1);
 158         if (--num == 0)
 159             return c1;
 160         mul(rp[1], ap[1], w, c1);
 161         if (--num == 0)
 162             return c1;
 163         mul(rp[2], ap[2], w, c1);
 164     }
 165     return (c1);
 166 }
 167
 168 void bn_sqr_words(BN_ULONG *r, const BN_ULONG *a, int n)
 169 {
 170     if (n <= 0)
 171         return;
 172
 173     while (n & ~3) {
 174         sqr(r[0], r[1], a[0]);
 175         sqr(r[2], r[3], a[1]);
 176         sqr(r[4], r[5], a[2]);
 177         sqr(r[6], r[7], a[3]);
 178         a += 4;
 179         r += 8;
 180         n -= 4;
 181     }
 182     if (n) {
 183         sqr(r[0], r[1], a[0]);
 184         if (--n == 0)
 185             return;
 186         sqr(r[2], r[3], a[1]);
 187         if (--n == 0)
 188             return;
 189         sqr(r[4], r[5], a[2]);
 190     }
 191 }
 192
 193 BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d)
 194 {
 195     BN_ULONG ret, waste;
 196
 197  asm("divq      %4":"=a"(ret), "=d"(waste)
 198  :     "a"(l), "d"(h), "g"(d)
 199  :     "cc");
 200
 201     return ret;
 202 }
 203
 204 BN_ULONG bn_add_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
 205                       int n)
 206 {
 207     BN_ULONG ret = 0, i = 0;
 208
 209     if (n <= 0)
 210         return 0;
 211
 212     asm volatile ("       subq    %2,%2           \n"
 213                   ".p2align 4                     \n"
 214                   "1:     movq    (%4,%2,8),%0    \n"
 215                   "       adcq    (%5,%2,8),%0    \n"
 216                   "       movq    %0,(%3,%2,8)    \n"
 217                   "       leaq    1(%2),%2        \n"
 218                   "       loop    1b              \n"
 219                   "       sbbq    %0,%0           \n":"=&a" (ret), "+c"(n),
 220                   "=&r"(i)
 221                   :"r"(rp), "r"(ap), "r"(bp)
 222                   :"cc", "memory");
 223
 224     return ret & 1;
 225 }
 226
 227 # ifndef SIMICS
 228 BN_ULONG bn_sub_words(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
 229                       int n)
 230 {
 231     BN_ULONG ret = 0, i = 0;
 232
 233     if (n <= 0)
 234         return 0;
 235
 236     asm volatile ("       subq    %2,%2           \n"
 237                   ".p2align 4                     \n"
 238                   "1:     movq    (%4,%2,8),%0    \n"
 239                   "       sbbq    (%5,%2,8),%0    \n"
 240                   "       movq    %0,(%3,%2,8)    \n"
 241                   "       leaq    1(%2),%2        \n"
 242                   "       loop    1b              \n"
 243                   "       sbbq    %0,%0           \n":"=&a" (ret), "+c"(n),
 244                   "=&r"(i)
 245                   :"r"(rp), "r"(ap), "r"(bp)
 246                   :"cc", "memory");
 247
 248     return ret & 1;
 249 }
 250 # else
 251 /* Simics 1.4<7 has buggy sbbq:-( */
 252 #  define BN_MASK2 0xffffffffffffffffL
 253 BN_ULONG bn_sub_words(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n)
 254 {
 255     BN_ULONG t1, t2;
 256     int c = 0;
 257
 258     if (n <= 0)
 259         return ((BN_ULONG)0);
 260
 261     for (;;) {
 262         t1 = a[0];
 263         t2 = b[0];
 264         r[0] = (t1 - t2 - c) & BN_MASK2;
 265         if (t1 != t2)
 266             c = (t1 < t2);
 267         if (--n <= 0)
 268             break;
 269
 270         t1 = a[1];
 271         t2 = b[1];
 272         r[1] = (t1 - t2 - c) & BN_MASK2;
 273         if (t1 != t2)
 274             c = (t1 < t2);
 275         if (--n <= 0)
 276             break;
 277
 278         t1 = a[2];
 279         t2 = b[2];
 280         r[2] = (t1 - t2 - c) & BN_MASK2;
 281         if (t1 != t2)
 282             c = (t1 < t2);
 283         if (--n <= 0)
 284             break;
 285
 286         t1 = a[3];
 287         t2 = b[3];
 288         r[3] = (t1 - t2 - c) & BN_MASK2;
 289         if (t1 != t2)
 290             c = (t1 < t2);
 291         if (--n <= 0)
 292             break;
 293
 294         a += 4;
 295         b += 4;
 296         r += 4;
 297     }
 298     return (c);
 299 }
 300 # endif
 301
 302 /* mul_add_c(a,b,c0,c1,c2)  -- c+=a*b for three word number c=(c2,c1,c0) */
 303 /* mul_add_c2(a,b,c0,c1,c2) -- c+=2*a*b for three word number c=(c2,c1,c0) */
 304 /* sqr_add_c(a,i,c0,c1,c2)  -- c+=a[i]^2 for three word number c=(c2,c1,c0) */
 305 /*
 306  * sqr_add_c2(a,i,c0,c1,c2) -- c+=2*a[i]*a[j] for three word number
 307  * c=(c2,c1,c0)
 308  */
 309
 310 /*
 311  * Keep in mind that carrying into high part of multiplication result
 312  * can not overflow, because it cannot be all-ones.
 313  */
 314 # if 0
 315 /* original macros are kept for reference purposes */
 316 #  define mul_add_c(a,b,c0,c1,c2) {       \
 317         BN_ULONG ta=(a),tb=(b);         \
 318         t1 = ta * tb;                   \
 319         t2 = BN_UMULT_HIGH(ta,tb);      \
 320         c0 += t1; t2 += (c0<t1)?1:0;    \
 321         c1 += t2; c2 += (c1<t2)?1:0;    \
 322         }
 323
 324 #  define mul_add_c2(a,b,c0,c1,c2) {      \
 325         BN_ULONG ta=(a),tb=(b),t0;      \
 326         t1 = BN_UMULT_HIGH(ta,tb);      \
 327         t0 = ta * tb;                   \
 328         c0 += t0; t2 = t1+((c0<t0)?1:0);\
 329         c1 += t2; c2 += (c1<t2)?1:0;    \
 330         c0 += t0; t1 += (c0<t0)?1:0;    \
 331         c1 += t1; c2 += (c1<t1)?1:0;    \
 332         }
 333 # else
 334 #  define mul_add_c(a,b,c0,c1,c2) do {    \
 335         asm ("mulq %3"                  \
 336                 : "=a"(t1),"=d"(t2)     \
 337                 : "a"(a),"m"(b)         \
 338                 : "cc");                \
 339         asm ("addq %2,%0; adcq %3,%1"   \
 340                 : "+r"(c0),"+d"(t2)     \
 341                 : "a"(t1),"g"(0)        \
 342                 : "cc");                \
 343         asm ("addq %2,%0; adcq %3,%1"   \
 344                 : "+r"(c1),"+r"(c2)     \
 345                 : "d"(t2),"g"(0)        \
 346                 : "cc");                \
 347         } while (0)
 348
 349 #  define sqr_add_c(a,i,c0,c1,c2) do {    \
 350         asm ("mulq %2"                  \
 351                 : "=a"(t1),"=d"(t2)     \
 352                 : "a"(a[i])             \
 353                 : "cc");                \
 354         asm ("addq %2,%0; adcq %3,%1"   \
 355                 : "+r"(c0),"+d"(t2)     \
 356                 : "a"(t1),"g"(0)        \
 357                 : "cc");                \
 358         asm ("addq %2,%0; adcq %3,%1"   \
 359                 : "+r"(c1),"+r"(c2)     \
 360                 : "d"(t2),"g"(0)        \
 361                 : "cc");                \
 362         } while (0)
 363
 364 #  define mul_add_c2(a,b,c0,c1,c2) do {   \
 365         asm ("mulq %3"                  \
 366                 : "=a"(t1),"=d"(t2)     \
 367                 : "a"(a),"m"(b)         \
 368                 : "cc");                \
 369         asm ("addq %3,%0; adcq %4,%1; adcq %5,%2"       \
 370                 : "+r"(c0),"+r"(c1),"+r"(c2)            \
 371                 : "r"(t1),"r"(t2),"g"(0)                \
 372                 : "cc");                                \
 373         asm ("addq %3,%0; adcq %4,%1; adcq %5,%2"       \
 374                 : "+r"(c0),"+r"(c1),"+r"(c2)            \
 375                 : "r"(t1),"r"(t2),"g"(0)                \
 376                 : "cc");                                \
 377         } while (0)
 378 # endif
 379
 380 # define sqr_add_c2(a,i,j,c0,c1,c2)      \
 381         mul_add_c2((a)[i],(a)[j],c0,c1,c2)
 382
 383 void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
 384 {
 385     BN_ULONG t1, t2;
 386     BN_ULONG c1, c2, c3;
 387
 388     c1 = 0;
 389     c2 = 0;
 390     c3 = 0;
 391     mul_add_c(a[0], b[0], c1, c2, c3);
 392     r[0] = c1;
 393     c1 = 0;
 394     mul_add_c(a[0], b[1], c2, c3, c1);
 395     mul_add_c(a[1], b[0], c2, c3, c1);
 396     r[1] = c2;
 397     c2 = 0;
 398     mul_add_c(a[2], b[0], c3, c1, c2);
 399     mul_add_c(a[1], b[1], c3, c1, c2);
 400     mul_add_c(a[0], b[2], c3, c1, c2);
 401     r[2] = c3;
 402     c3 = 0;
 403     mul_add_c(a[0], b[3], c1, c2, c3);
 404     mul_add_c(a[1], b[2], c1, c2, c3);
 405     mul_add_c(a[2], b[1], c1, c2, c3);
 406     mul_add_c(a[3], b[0], c1, c2, c3);
 407     r[3] = c1;
 408     c1 = 0;
 409     mul_add_c(a[4], b[0], c2, c3, c1);
 410     mul_add_c(a[3], b[1], c2, c3, c1);
 411     mul_add_c(a[2], b[2], c2, c3, c1);
 412     mul_add_c(a[1], b[3], c2, c3, c1);
 413     mul_add_c(a[0], b[4], c2, c3, c1);
 414     r[4] = c2;
 415     c2 = 0;
 416     mul_add_c(a[0], b[5], c3, c1, c2);
 417     mul_add_c(a[1], b[4], c3, c1, c2);
 418     mul_add_c(a[2], b[3], c3, c1, c2);
 419     mul_add_c(a[3], b[2], c3, c1, c2);
 420     mul_add_c(a[4], b[1], c3, c1, c2);
 421     mul_add_c(a[5], b[0], c3, c1, c2);
 422     r[5] = c3;
 423     c3 = 0;
 424     mul_add_c(a[6], b[0], c1, c2, c3);
 425     mul_add_c(a[5], b[1], c1, c2, c3);
 426     mul_add_c(a[4], b[2], c1, c2, c3);
 427     mul_add_c(a[3], b[3], c1, c2, c3);
 428     mul_add_c(a[2], b[4], c1, c2, c3);
 429     mul_add_c(a[1], b[5], c1, c2, c3);
 430     mul_add_c(a[0], b[6], c1, c2, c3);
 431     r[6] = c1;
 432     c1 = 0;
 433     mul_add_c(a[0], b[7], c2, c3, c1);
 434     mul_add_c(a[1], b[6], c2, c3, c1);
 435     mul_add_c(a[2], b[5], c2, c3, c1);
 436     mul_add_c(a[3], b[4], c2, c3, c1);
 437     mul_add_c(a[4], b[3], c2, c3, c1);
 438     mul_add_c(a[5], b[2], c2, c3, c1);
 439     mul_add_c(a[6], b[1], c2, c3, c1);
 440     mul_add_c(a[7], b[0], c2, c3, c1);
 441     r[7] = c2;
 442     c2 = 0;
 443     mul_add_c(a[7], b[1], c3, c1, c2);
 444     mul_add_c(a[6], b[2], c3, c1, c2);
 445     mul_add_c(a[5], b[3], c3, c1, c2);
 446     mul_add_c(a[4], b[4], c3, c1, c2);
 447     mul_add_c(a[3], b[5], c3, c1, c2);
 448     mul_add_c(a[2], b[6], c3, c1, c2);
 449     mul_add_c(a[1], b[7], c3, c1, c2);
 450     r[8] = c3;
 451     c3 = 0;
 452     mul_add_c(a[2], b[7], c1, c2, c3);
 453     mul_add_c(a[3], b[6], c1, c2, c3);
 454     mul_add_c(a[4], b[5], c1, c2, c3);
 455     mul_add_c(a[5], b[4], c1, c2, c3);
 456     mul_add_c(a[6], b[3], c1, c2, c3);
 457     mul_add_c(a[7], b[2], c1, c2, c3);
 458     r[9] = c1;
 459     c1 = 0;
 460     mul_add_c(a[7], b[3], c2, c3, c1);
 461     mul_add_c(a[6], b[4], c2, c3, c1);
 462     mul_add_c(a[5], b[5], c2, c3, c1);
 463     mul_add_c(a[4], b[6], c2, c3, c1);
 464     mul_add_c(a[3], b[7], c2, c3, c1);
 465     r[10] = c2;
 466     c2 = 0;
 467     mul_add_c(a[4], b[7], c3, c1, c2);
 468     mul_add_c(a[5], b[6], c3, c1, c2);
 469     mul_add_c(a[6], b[5], c3, c1, c2);
 470     mul_add_c(a[7], b[4], c3, c1, c2);
 471     r[11] = c3;
 472     c3 = 0;
 473     mul_add_c(a[7], b[5], c1, c2, c3);
 474     mul_add_c(a[6], b[6], c1, c2, c3);
 475     mul_add_c(a[5], b[7], c1, c2, c3);
 476     r[12] = c1;
 477     c1 = 0;
 478     mul_add_c(a[6], b[7], c2, c3, c1);
 479     mul_add_c(a[7], b[6], c2, c3, c1);
 480     r[13] = c2;
 481     c2 = 0;
 482     mul_add_c(a[7], b[7], c3, c1, c2);
 483     r[14] = c3;
 484     r[15] = c1;
 485 }
 486
 487 void bn_mul_comba4(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
 488 {
 489     BN_ULONG t1, t2;
 490     BN_ULONG c1, c2, c3;
 491
 492     c1 = 0;
 493     c2 = 0;
 494     c3 = 0;
 495     mul_add_c(a[0], b[0], c1, c2, c3);
 496     r[0] = c1;
 497     c1 = 0;
 498     mul_add_c(a[0], b[1], c2, c3, c1);
 499     mul_add_c(a[1], b[0], c2, c3, c1);
 500     r[1] = c2;
 501     c2 = 0;
 502     mul_add_c(a[2], b[0], c3, c1, c2);
 503     mul_add_c(a[1], b[1], c3, c1, c2);
 504     mul_add_c(a[0], b[2], c3, c1, c2);
 505     r[2] = c3;
 506     c3 = 0;
 507     mul_add_c(a[0], b[3], c1, c2, c3);
 508     mul_add_c(a[1], b[2], c1, c2, c3);
 509     mul_add_c(a[2], b[1], c1, c2, c3);
 510     mul_add_c(a[3], b[0], c1, c2, c3);
 511     r[3] = c1;
 512     c1 = 0;
 513     mul_add_c(a[3], b[1], c2, c3, c1);
 514     mul_add_c(a[2], b[2], c2, c3, c1);
 515     mul_add_c(a[1], b[3], c2, c3, c1);
 516     r[4] = c2;
 517     c2 = 0;
 518     mul_add_c(a[2], b[3], c3, c1, c2);
 519     mul_add_c(a[3], b[2], c3, c1, c2);
 520     r[5] = c3;
 521     c3 = 0;
 522     mul_add_c(a[3], b[3], c1, c2, c3);
 523     r[6] = c1;
 524     r[7] = c2;
 525 }
 526
 527 void bn_sqr_comba8(BN_ULONG *r, const BN_ULONG *a)
 528 {
 529     BN_ULONG t1, t2;
 530     BN_ULONG c1, c2, c3;
 531
 532     c1 = 0;
 533     c2 = 0;
 534     c3 = 0;
 535     sqr_add_c(a, 0, c1, c2, c3);
 536     r[0] = c1;
 537     c1 = 0;
 538     sqr_add_c2(a, 1, 0, c2, c3, c1);
 539     r[1] = c2;
 540     c2 = 0;
 541     sqr_add_c(a, 1, c3, c1, c2);
 542     sqr_add_c2(a, 2, 0, c3, c1, c2);
 543     r[2] = c3;
 544     c3 = 0;
 545     sqr_add_c2(a, 3, 0, c1, c2, c3);
 546     sqr_add_c2(a, 2, 1, c1, c2, c3);
 547     r[3] = c1;
 548     c1 = 0;
 549     sqr_add_c(a, 2, c2, c3, c1);
 550     sqr_add_c2(a, 3, 1, c2, c3, c1);
 551     sqr_add_c2(a, 4, 0, c2, c3, c1);
 552     r[4] = c2;
 553     c2 = 0;
 554     sqr_add_c2(a, 5, 0, c3, c1, c2);
 555     sqr_add_c2(a, 4, 1, c3, c1, c2);
 556     sqr_add_c2(a, 3, 2, c3, c1, c2);
 557     r[5] = c3;
 558     c3 = 0;
 559     sqr_add_c(a, 3, c1, c2, c3);
 560     sqr_add_c2(a, 4, 2, c1, c2, c3);
 561     sqr_add_c2(a, 5, 1, c1, c2, c3);
 562     sqr_add_c2(a, 6, 0, c1, c2, c3);
 563     r[6] = c1;
 564     c1 = 0;
 565     sqr_add_c2(a, 7, 0, c2, c3, c1);
 566     sqr_add_c2(a, 6, 1, c2, c3, c1);
 567     sqr_add_c2(a, 5, 2, c2, c3, c1);
 568     sqr_add_c2(a, 4, 3, c2, c3, c1);
 569     r[7] = c2;
 570     c2 = 0;
 571     sqr_add_c(a, 4, c3, c1, c2);
 572     sqr_add_c2(a, 5, 3, c3, c1, c2);
 573     sqr_add_c2(a, 6, 2, c3, c1, c2);
 574     sqr_add_c2(a, 7, 1, c3, c1, c2);
 575     r[8] = c3;
 576     c3 = 0;
 577     sqr_add_c2(a, 7, 2, c1, c2, c3);
 578     sqr_add_c2(a, 6, 3, c1, c2, c3);
 579     sqr_add_c2(a, 5, 4, c1, c2, c3);
 580     r[9] = c1;
 581     c1 = 0;
 582     sqr_add_c(a, 5, c2, c3, c1);
 583     sqr_add_c2(a, 6, 4, c2, c3, c1);
 584     sqr_add_c2(a, 7, 3, c2, c3, c1);
 585     r[10] = c2;
 586     c2 = 0;
 587     sqr_add_c2(a, 7, 4, c3, c1, c2);
 588     sqr_add_c2(a, 6, 5, c3, c1, c2);
 589     r[11] = c3;
 590     c3 = 0;
 591     sqr_add_c(a, 6, c1, c2, c3);
 592     sqr_add_c2(a, 7, 5, c1, c2, c3);
 593     r[12] = c1;
 594     c1 = 0;
 595     sqr_add_c2(a, 7, 6, c2, c3, c1);
 596     r[13] = c2;
 597     c2 = 0;
 598     sqr_add_c(a, 7, c3, c1, c2);
 599     r[14] = c3;
 600     r[15] = c1;
 601 }
 602
 603 void bn_sqr_comba4(BN_ULONG *r, const BN_ULONG *a)
 604 {
 605     BN_ULONG t1, t2;
 606     BN_ULONG c1, c2, c3;
 607
 608     c1 = 0;
 609     c2 = 0;
 610     c3 = 0;
 611     sqr_add_c(a, 0, c1, c2, c3);
 612     r[0] = c1;
 613     c1 = 0;
 614     sqr_add_c2(a, 1, 0, c2, c3, c1);
 615     r[1] = c2;
 616     c2 = 0;
 617     sqr_add_c(a, 1, c3, c1, c2);
 618     sqr_add_c2(a, 2, 0, c3, c1, c2);
 619     r[2] = c3;
 620     c3 = 0;
 621     sqr_add_c2(a, 3, 0, c1, c2, c3);
 622     sqr_add_c2(a, 2, 1, c1, c2, c3);
 623     r[3] = c1;
 624     c1 = 0;
 625     sqr_add_c(a, 2, c2, c3, c1);
 626     sqr_add_c2(a, 3, 1, c2, c3, c1);
 627     r[4] = c2;
 628     c2 = 0;
 629     sqr_add_c2(a, 3, 2, c3, c1, c2);
 630     r[5] = c3;
 631     c3 = 0;
 632     sqr_add_c(a, 3, c1, c2, c3);
 633     r[6] = c1;
 634     r[7] = c2;
 635 }
 636 #endif