1#!/usr/bin/env perl 2 3# ==================================================================== 4# Written by Andy Polyakov <appro@fy.chalmers.se> for the OpenSSL 5# project. The module is, however, dual licensed under OpenSSL and 6# CRYPTOGAMS licenses depending on where you obtain it. For further 7# details see http://www.openssl.org/~appro/cryptogams/. 8# ==================================================================== 9 10# October 2005 11# 12# This is a "teaser" code, as it can be improved in several ways... 13# First of all non-SSE2 path should be implemented (yes, for now it 14# performs Montgomery multiplication/convolution only on SSE2-capable 15# CPUs such as P4, others fall down to original code). Then inner loop 16# can be unrolled and modulo-scheduled to improve ILP and possibly 17# moved to 128-bit XMM register bank (though it would require input 18# rearrangement and/or increase bus bandwidth utilization). Dedicated 19# squaring procedure should give further performance improvement... 20# Yet, for being draft, the code improves rsa512 *sign* benchmark by 21# 110%(!), rsa1024 one - by 70% and rsa4096 - by 20%:-) 22 23# December 2006 24# 25# Modulo-scheduling SSE2 loops results in further 15-20% improvement. 26# Integer-only code [being equipped with dedicated squaring procedure] 27# gives ~40% on rsa512 sign benchmark... 28 29$0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1; 30push(@INC,"${dir}","${dir}../../perlasm"); 31require "x86asm.pl"; 32 33&asm_init($ARGV[0],$0); 34 35$sse2=0; 36for (@ARGV) { $sse2=1 if (/-DOPENSSL_IA32_SSE2/); } 37 38&external_label("OPENSSL_ia32cap_P") if ($sse2); 39 40&function_begin("bn_mul_mont"); 41 42$i="edx"; 43$j="ecx"; 44$ap="esi"; $tp="esi"; # overlapping variables!!! 45$rp="edi"; $bp="edi"; # overlapping variables!!! 46$np="ebp"; 47$num="ebx"; 48 49$_num=&DWP(4*0,"esp"); # stack top layout 50$_rp=&DWP(4*1,"esp"); 51$_ap=&DWP(4*2,"esp"); 52$_bp=&DWP(4*3,"esp"); 53$_np=&DWP(4*4,"esp"); 54$_n0=&DWP(4*5,"esp"); $_n0q=&QWP(4*5,"esp"); 55$_sp=&DWP(4*6,"esp"); 56$_bpend=&DWP(4*7,"esp"); 57$frame=32; # size of above frame rounded up to 16n 58 59 &xor ("eax","eax"); 60 &mov ("edi",&wparam(5)); # int num 61 &cmp ("edi",4); 62 &jl (&label("just_leave")); 63 64 &lea ("esi",&wparam(0)); # put aside pointer to argument block 65 &lea ("edx",&wparam(1)); # load ap 66 &mov ("ebp","esp"); # saved stack pointer! 67 &add ("edi",2); # extra two words on top of tp 68 &neg ("edi"); 69 &lea ("esp",&DWP(-$frame,"esp","edi",4)); # alloca($frame+4*(num+2)) 70 &neg ("edi"); 71 72 # minimize cache contention by arraning 2K window between stack 73 # pointer and ap argument [np is also position sensitive vector, 74 # but it's assumed to be near ap, as it's allocated at ~same 75 # time]. 76 &mov ("eax","esp"); 77 &sub ("eax","edx"); 78 &and ("eax",2047); 79 &sub ("esp","eax"); # this aligns sp and ap modulo 2048 80 81 &xor ("edx","esp"); 82 &and ("edx",2048); 83 &xor ("edx",2048); 84 &sub ("esp","edx"); # this splits them apart modulo 4096 85 86 &and ("esp",-64); # align to cache line 87 88 ################################# load argument block... 89 &mov ("eax",&DWP(0*4,"esi"));# BN_ULONG *rp 90 &mov ("ebx",&DWP(1*4,"esi"));# const BN_ULONG *ap 91 &mov ("ecx",&DWP(2*4,"esi"));# const BN_ULONG *bp 92 &mov ("edx",&DWP(3*4,"esi"));# const BN_ULONG *np 93 &mov ("esi",&DWP(4*4,"esi"));# const BN_ULONG *n0 94 #&mov ("edi",&DWP(5*4,"esi"));# int num 95 96 &mov ("esi",&DWP(0,"esi")); # pull n0[0] 97 &mov ($_rp,"eax"); # ... save a copy of argument block 98 &mov ($_ap,"ebx"); 99 &mov ($_bp,"ecx"); 100 &mov ($_np,"edx"); 101 &mov ($_n0,"esi"); 102 &lea ($num,&DWP(-3,"edi")); # num=num-1 to assist modulo-scheduling 103 #&mov ($_num,$num); # redundant as $num is not reused 104 &mov ($_sp,"ebp"); # saved stack pointer! 105 106if($sse2) { 107$acc0="mm0"; # mmx register bank layout 108$acc1="mm1"; 109$car0="mm2"; 110$car1="mm3"; 111$mul0="mm4"; 112$mul1="mm5"; 113$temp="mm6"; 114$mask="mm7"; 115 116 &picmeup("eax","OPENSSL_ia32cap_P"); 117 &bt (&DWP(0,"eax"),26); 118 &jnc (&label("non_sse2")); 119 120 &mov ("eax",-1); 121 &movd ($mask,"eax"); # mask 32 lower bits 122 123 &mov ($ap,$_ap); # load input pointers 124 &mov ($bp,$_bp); 125 &mov ($np,$_np); 126 127 &xor ($i,$i); # i=0 128 &xor ($j,$j); # j=0 129 130 &movd ($mul0,&DWP(0,$bp)); # bp[0] 131 &movd ($mul1,&DWP(0,$ap)); # ap[0] 132 &movd ($car1,&DWP(0,$np)); # np[0] 133 134 &pmuludq($mul1,$mul0); # ap[0]*bp[0] 135 &movq ($car0,$mul1); 136 &movq ($acc0,$mul1); # I wish movd worked for 137 &pand ($acc0,$mask); # inter-register transfers 138 139 &pmuludq($mul1,$_n0q); # *=n0 140 141 &pmuludq($car1,$mul1); # "t[0]"*np[0]*n0 142 &paddq ($car1,$acc0); 143 144 &movd ($acc1,&DWP(4,$np)); # np[1] 145 &movd ($acc0,&DWP(4,$ap)); # ap[1] 146 147 &psrlq ($car0,32); 148 &psrlq ($car1,32); 149 150 &inc ($j); # j++ 151&set_label("1st",16); 152 &pmuludq($acc0,$mul0); # ap[j]*bp[0] 153 &pmuludq($acc1,$mul1); # np[j]*m1 154 &paddq ($car0,$acc0); # +=c0 155 &paddq ($car1,$acc1); # +=c1 156 157 &movq ($acc0,$car0); 158 &pand ($acc0,$mask); 159 &movd ($acc1,&DWP(4,$np,$j,4)); # np[j+1] 160 &paddq ($car1,$acc0); # +=ap[j]*bp[0]; 161 &movd ($acc0,&DWP(4,$ap,$j,4)); # ap[j+1] 162 &psrlq ($car0,32); 163 &movd (&DWP($frame-4,"esp",$j,4),$car1); # tp[j-1]= 164 &psrlq ($car1,32); 165 166 &lea ($j,&DWP(1,$j)); 167 &cmp ($j,$num); 168 &jl (&label("1st")); 169 170 &pmuludq($acc0,$mul0); # ap[num-1]*bp[0] 171 &pmuludq($acc1,$mul1); # np[num-1]*m1 172 &paddq ($car0,$acc0); # +=c0 173 &paddq ($car1,$acc1); # +=c1 174 175 &movq ($acc0,$car0); 176 &pand ($acc0,$mask); 177 &paddq ($car1,$acc0); # +=ap[num-1]*bp[0]; 178 &movd (&DWP($frame-4,"esp",$j,4),$car1); # tp[num-2]= 179 180 &psrlq ($car0,32); 181 &psrlq ($car1,32); 182 183 &paddq ($car1,$car0); 184 &movq (&QWP($frame,"esp",$num,4),$car1); # tp[num].tp[num-1] 185 186 &inc ($i); # i++ 187&set_label("outer"); 188 &xor ($j,$j); # j=0 189 190 &movd ($mul0,&DWP(0,$bp,$i,4)); # bp[i] 191 &movd ($mul1,&DWP(0,$ap)); # ap[0] 192 &movd ($temp,&DWP($frame,"esp")); # tp[0] 193 &movd ($car1,&DWP(0,$np)); # np[0] 194 &pmuludq($mul1,$mul0); # ap[0]*bp[i] 195 196 &paddq ($mul1,$temp); # +=tp[0] 197 &movq ($acc0,$mul1); 198 &movq ($car0,$mul1); 199 &pand ($acc0,$mask); 200 201 &pmuludq($mul1,$_n0q); # *=n0 202 203 &pmuludq($car1,$mul1); 204 &paddq ($car1,$acc0); 205 206 &movd ($temp,&DWP($frame+4,"esp")); # tp[1] 207 &movd ($acc1,&DWP(4,$np)); # np[1] 208 &movd ($acc0,&DWP(4,$ap)); # ap[1] 209 210 &psrlq ($car0,32); 211 &psrlq ($car1,32); 212 &paddq ($car0,$temp); # +=tp[1] 213 214 &inc ($j); # j++ 215 &dec ($num); 216&set_label("inner"); 217 &pmuludq($acc0,$mul0); # ap[j]*bp[i] 218 &pmuludq($acc1,$mul1); # np[j]*m1 219 &paddq ($car0,$acc0); # +=c0 220 &paddq ($car1,$acc1); # +=c1 221 222 &movq ($acc0,$car0); 223 &movd ($temp,&DWP($frame+4,"esp",$j,4));# tp[j+1] 224 &pand ($acc0,$mask); 225 &movd ($acc1,&DWP(4,$np,$j,4)); # np[j+1] 226 &paddq ($car1,$acc0); # +=ap[j]*bp[i]+tp[j] 227 &movd ($acc0,&DWP(4,$ap,$j,4)); # ap[j+1] 228 &psrlq ($car0,32); 229 &movd (&DWP($frame-4,"esp",$j,4),$car1);# tp[j-1]= 230 &psrlq ($car1,32); 231 &paddq ($car0,$temp); # +=tp[j+1] 232 233 &dec ($num); 234 &lea ($j,&DWP(1,$j)); # j++ 235 &jnz (&label("inner")); 236 237 &mov ($num,$j); 238 &pmuludq($acc0,$mul0); # ap[num-1]*bp[i] 239 &pmuludq($acc1,$mul1); # np[num-1]*m1 240 &paddq ($car0,$acc0); # +=c0 241 &paddq ($car1,$acc1); # +=c1 242 243 &movq ($acc0,$car0); 244 &pand ($acc0,$mask); 245 &paddq ($car1,$acc0); # +=ap[num-1]*bp[i]+tp[num-1] 246 &movd (&DWP($frame-4,"esp",$j,4),$car1); # tp[num-2]= 247 &psrlq ($car0,32); 248 &psrlq ($car1,32); 249 250 &movd ($temp,&DWP($frame+4,"esp",$num,4)); # += tp[num] 251 &paddq ($car1,$car0); 252 &paddq ($car1,$temp); 253 &movq (&QWP($frame,"esp",$num,4),$car1); # tp[num].tp[num-1] 254 255 &lea ($i,&DWP(1,$i)); # i++ 256 &cmp ($i,$num); 257 &jle (&label("outer")); 258 259 &emms (); # done with mmx bank 260 &jmp (&label("common_tail")); 261 262&set_label("non_sse2",16); 263} 264 265if (0) { 266 &mov ("esp",$_sp); 267 &xor ("eax","eax"); # signal "not fast enough [yet]" 268 &jmp (&label("just_leave")); 269 # While the below code provides competitive performance for 270 # all key lengthes on modern Intel cores, it's still more 271 # than 10% slower for 4096-bit key elsewhere:-( "Competitive" 272 # means compared to the original integer-only assembler. 273 # 512-bit RSA sign is better by ~40%, but that's about all 274 # one can say about all CPUs... 275} else { 276$inp="esi"; # integer path uses these registers differently 277$word="edi"; 278$carry="ebp"; 279 280 &mov ($inp,$_ap); 281 &lea ($carry,&DWP(1,$num)); 282 &mov ($word,$_bp); 283 &xor ($j,$j); # j=0 284 &mov ("edx",$inp); 285 &and ($carry,1); # see if num is even 286 &sub ("edx",$word); # see if ap==bp 287 &lea ("eax",&DWP(4,$word,$num,4)); # &bp[num] 288 &or ($carry,"edx"); 289 &mov ($word,&DWP(0,$word)); # bp[0] 290 &jz (&label("bn_sqr_mont")); 291 &mov ($_bpend,"eax"); 292 &mov ("eax",&DWP(0,$inp)); 293 &xor ("edx","edx"); 294 295&set_label("mull",16); 296 &mov ($carry,"edx"); 297 &mul ($word); # ap[j]*bp[0] 298 &add ($carry,"eax"); 299 &lea ($j,&DWP(1,$j)); 300 &adc ("edx",0); 301 &mov ("eax",&DWP(0,$inp,$j,4)); # ap[j+1] 302 &cmp ($j,$num); 303 &mov (&DWP($frame-4,"esp",$j,4),$carry); # tp[j]= 304 &jl (&label("mull")); 305 306 &mov ($carry,"edx"); 307 &mul ($word); # ap[num-1]*bp[0] 308 &mov ($word,$_n0); 309 &add ("eax",$carry); 310 &mov ($inp,$_np); 311 &adc ("edx",0); 312 &imul ($word,&DWP($frame,"esp")); # n0*tp[0] 313 314 &mov (&DWP($frame,"esp",$num,4),"eax"); # tp[num-1]= 315 &xor ($j,$j); 316 &mov (&DWP($frame+4,"esp",$num,4),"edx"); # tp[num]= 317 &mov (&DWP($frame+8,"esp",$num,4),$j); # tp[num+1]= 318 319 &mov ("eax",&DWP(0,$inp)); # np[0] 320 &mul ($word); # np[0]*m 321 &add ("eax",&DWP($frame,"esp")); # +=tp[0] 322 &mov ("eax",&DWP(4,$inp)); # np[1] 323 &adc ("edx",0); 324 &inc ($j); 325 326 &jmp (&label("2ndmadd")); 327 328&set_label("1stmadd",16); 329 &mov ($carry,"edx"); 330 &mul ($word); # ap[j]*bp[i] 331 &add ($carry,&DWP($frame,"esp",$j,4)); # +=tp[j] 332 &lea ($j,&DWP(1,$j)); 333 &adc ("edx",0); 334 &add ($carry,"eax"); 335 &mov ("eax",&DWP(0,$inp,$j,4)); # ap[j+1] 336 &adc ("edx",0); 337 &cmp ($j,$num); 338 &mov (&DWP($frame-4,"esp",$j,4),$carry); # tp[j]= 339 &jl (&label("1stmadd")); 340 341 &mov ($carry,"edx"); 342 &mul ($word); # ap[num-1]*bp[i] 343 &add ("eax",&DWP($frame,"esp",$num,4)); # +=tp[num-1] 344 &mov ($word,$_n0); 345 &adc ("edx",0); 346 &mov ($inp,$_np); 347 &add ($carry,"eax"); 348 &adc ("edx",0); 349 &imul ($word,&DWP($frame,"esp")); # n0*tp[0] 350 351 &xor ($j,$j); 352 &add ("edx",&DWP($frame+4,"esp",$num,4)); # carry+=tp[num] 353 &mov (&DWP($frame,"esp",$num,4),$carry); # tp[num-1]= 354 &adc ($j,0); 355 &mov ("eax",&DWP(0,$inp)); # np[0] 356 &mov (&DWP($frame+4,"esp",$num,4),"edx"); # tp[num]= 357 &mov (&DWP($frame+8,"esp",$num,4),$j); # tp[num+1]= 358 359 &mul ($word); # np[0]*m 360 &add ("eax",&DWP($frame,"esp")); # +=tp[0] 361 &mov ("eax",&DWP(4,$inp)); # np[1] 362 &adc ("edx",0); 363 &mov ($j,1); 364 365&set_label("2ndmadd",16); 366 &mov ($carry,"edx"); 367 &mul ($word); # np[j]*m 368 &add ($carry,&DWP($frame,"esp",$j,4)); # +=tp[j] 369 &lea ($j,&DWP(1,$j)); 370 &adc ("edx",0); 371 &add ($carry,"eax"); 372 &mov ("eax",&DWP(0,$inp,$j,4)); # np[j+1] 373 &adc ("edx",0); 374 &cmp ($j,$num); 375 &mov (&DWP($frame-8,"esp",$j,4),$carry); # tp[j-1]= 376 &jl (&label("2ndmadd")); 377 378 &mov ($carry,"edx"); 379 &mul ($word); # np[j]*m 380 &add ($carry,&DWP($frame,"esp",$num,4)); # +=tp[num-1] 381 &adc ("edx",0); 382 &add ($carry,"eax"); 383 &adc ("edx",0); 384 &mov (&DWP($frame-4,"esp",$num,4),$carry); # tp[num-2]= 385 386 &xor ("eax","eax"); 387 &mov ($j,$_bp); # &bp[i] 388 &add ("edx",&DWP($frame+4,"esp",$num,4)); # carry+=tp[num] 389 &adc ("eax",&DWP($frame+8,"esp",$num,4)); # +=tp[num+1] 390 &lea ($j,&DWP(4,$j)); 391 &mov (&DWP($frame,"esp",$num,4),"edx"); # tp[num-1]= 392 &cmp ($j,$_bpend); 393 &mov (&DWP($frame+4,"esp",$num,4),"eax"); # tp[num]= 394 &je (&label("common_tail")); 395 396 &mov ($word,&DWP(0,$j)); # bp[i+1] 397 &mov ($inp,$_ap); 398 &mov ($_bp,$j); # &bp[++i] 399 &xor ($j,$j); 400 &xor ("edx","edx"); 401 &mov ("eax",&DWP(0,$inp)); 402 &jmp (&label("1stmadd")); 403 404&set_label("bn_sqr_mont",16); 405$sbit=$num; 406 &mov ($_num,$num); 407 &mov ($_bp,$j); # i=0 408 409 &mov ("eax",$word); # ap[0] 410 &mul ($word); # ap[0]*ap[0] 411 &mov (&DWP($frame,"esp"),"eax"); # tp[0]= 412 &mov ($sbit,"edx"); 413 &shr ("edx",1); 414 &and ($sbit,1); 415 &inc ($j); 416&set_label("sqr",16); 417 &mov ("eax",&DWP(0,$inp,$j,4)); # ap[j] 418 &mov ($carry,"edx"); 419 &mul ($word); # ap[j]*ap[0] 420 &add ("eax",$carry); 421 &lea ($j,&DWP(1,$j)); 422 &adc ("edx",0); 423 &lea ($carry,&DWP(0,$sbit,"eax",2)); 424 &shr ("eax",31); 425 &cmp ($j,$_num); 426 &mov ($sbit,"eax"); 427 &mov (&DWP($frame-4,"esp",$j,4),$carry); # tp[j]= 428 &jl (&label("sqr")); 429 430 &mov ("eax",&DWP(0,$inp,$j,4)); # ap[num-1] 431 &mov ($carry,"edx"); 432 &mul ($word); # ap[num-1]*ap[0] 433 &add ("eax",$carry); 434 &mov ($word,$_n0); 435 &adc ("edx",0); 436 &mov ($inp,$_np); 437 &lea ($carry,&DWP(0,$sbit,"eax",2)); 438 &imul ($word,&DWP($frame,"esp")); # n0*tp[0] 439 &shr ("eax",31); 440 &mov (&DWP($frame,"esp",$j,4),$carry); # tp[num-1]= 441 442 &lea ($carry,&DWP(0,"eax","edx",2)); 443 &mov ("eax",&DWP(0,$inp)); # np[0] 444 &shr ("edx",31); 445 &mov (&DWP($frame+4,"esp",$j,4),$carry); # tp[num]= 446 &mov (&DWP($frame+8,"esp",$j,4),"edx"); # tp[num+1]= 447 448 &mul ($word); # np[0]*m 449 &add ("eax",&DWP($frame,"esp")); # +=tp[0] 450 &mov ($num,$j); 451 &adc ("edx",0); 452 &mov ("eax",&DWP(4,$inp)); # np[1] 453 &mov ($j,1); 454 455&set_label("3rdmadd",16); 456 &mov ($carry,"edx"); 457 &mul ($word); # np[j]*m 458 &add ($carry,&DWP($frame,"esp",$j,4)); # +=tp[j] 459 &adc ("edx",0); 460 &add ($carry,"eax"); 461 &mov ("eax",&DWP(4,$inp,$j,4)); # np[j+1] 462 &adc ("edx",0); 463 &mov (&DWP($frame-4,"esp",$j,4),$carry); # tp[j-1]= 464 465 &mov ($carry,"edx"); 466 &mul ($word); # np[j+1]*m 467 &add ($carry,&DWP($frame+4,"esp",$j,4)); # +=tp[j+1] 468 &lea ($j,&DWP(2,$j)); 469 &adc ("edx",0); 470 &add ($carry,"eax"); 471 &mov ("eax",&DWP(0,$inp,$j,4)); # np[j+2] 472 &adc ("edx",0); 473 &cmp ($j,$num); 474 &mov (&DWP($frame-8,"esp",$j,4),$carry); # tp[j]= 475 &jl (&label("3rdmadd")); 476 477 &mov ($carry,"edx"); 478 &mul ($word); # np[j]*m 479 &add ($carry,&DWP($frame,"esp",$num,4)); # +=tp[num-1] 480 &adc ("edx",0); 481 &add ($carry,"eax"); 482 &adc ("edx",0); 483 &mov (&DWP($frame-4,"esp",$num,4),$carry); # tp[num-2]= 484 485 &mov ($j,$_bp); # i 486 &xor ("eax","eax"); 487 &mov ($inp,$_ap); 488 &add ("edx",&DWP($frame+4,"esp",$num,4)); # carry+=tp[num] 489 &adc ("eax",&DWP($frame+8,"esp",$num,4)); # +=tp[num+1] 490 &mov (&DWP($frame,"esp",$num,4),"edx"); # tp[num-1]= 491 &cmp ($j,$num); 492 &mov (&DWP($frame+4,"esp",$num,4),"eax"); # tp[num]= 493 &je (&label("common_tail")); 494 495 &mov ($word,&DWP(4,$inp,$j,4)); # ap[i] 496 &lea ($j,&DWP(1,$j)); 497 &mov ("eax",$word); 498 &mov ($_bp,$j); # ++i 499 &mul ($word); # ap[i]*ap[i] 500 &add ("eax",&DWP($frame,"esp",$j,4)); # +=tp[i] 501 &adc ("edx",0); 502 &mov (&DWP($frame,"esp",$j,4),"eax"); # tp[i]= 503 &xor ($carry,$carry); 504 &cmp ($j,$num); 505 &lea ($j,&DWP(1,$j)); 506 &je (&label("sqrlast")); 507 508 &mov ($sbit,"edx"); # zaps $num 509 &shr ("edx",1); 510 &and ($sbit,1); 511&set_label("sqradd",16); 512 &mov ("eax",&DWP(0,$inp,$j,4)); # ap[j] 513 &mov ($carry,"edx"); 514 &mul ($word); # ap[j]*ap[i] 515 &add ("eax",$carry); 516 &lea ($carry,&DWP(0,"eax","eax")); 517 &adc ("edx",0); 518 &shr ("eax",31); 519 &add ($carry,&DWP($frame,"esp",$j,4)); # +=tp[j] 520 &lea ($j,&DWP(1,$j)); 521 &adc ("eax",0); 522 &add ($carry,$sbit); 523 &adc ("eax",0); 524 &cmp ($j,$_num); 525 &mov (&DWP($frame-4,"esp",$j,4),$carry); # tp[j]= 526 &mov ($sbit,"eax"); 527 &jle (&label("sqradd")); 528 529 &mov ($carry,"edx"); 530 &add ("edx","edx"); 531 &shr ($carry,31); 532 &add ("edx",$sbit); 533 &adc ($carry,0); 534&set_label("sqrlast"); 535 &mov ($word,$_n0); 536 &mov ($inp,$_np); 537 &imul ($word,&DWP($frame,"esp")); # n0*tp[0] 538 539 &add ("edx",&DWP($frame,"esp",$j,4)); # +=tp[num] 540 &mov ("eax",&DWP(0,$inp)); # np[0] 541 &adc ($carry,0); 542 &mov (&DWP($frame,"esp",$j,4),"edx"); # tp[num]= 543 &mov (&DWP($frame+4,"esp",$j,4),$carry); # tp[num+1]= 544 545 &mul ($word); # np[0]*m 546 &add ("eax",&DWP($frame,"esp")); # +=tp[0] 547 &lea ($num,&DWP(-1,$j)); 548 &adc ("edx",0); 549 &mov ($j,1); 550 &mov ("eax",&DWP(4,$inp)); # np[1] 551 552 &jmp (&label("3rdmadd")); 553} 554 555&set_label("common_tail",16); 556 &mov ($np,$_np); # load modulus pointer 557 &mov ($rp,$_rp); # load result pointer 558 &lea ($tp,&DWP($frame,"esp")); # [$ap and $bp are zapped] 559 560 &mov ("eax",&DWP(0,$tp)); # tp[0] 561 &mov ($j,$num); # j=num-1 562 &xor ($i,$i); # i=0 and clear CF! 563 564&set_label("sub",16); 565 &sbb ("eax",&DWP(0,$np,$i,4)); 566 &mov (&DWP(0,$rp,$i,4),"eax"); # rp[i]=tp[i]-np[i] 567 &dec ($j); # doesn't affect CF! 568 &mov ("eax",&DWP(4,$tp,$i,4)); # tp[i+1] 569 &lea ($i,&DWP(1,$i)); # i++ 570 &jge (&label("sub")); 571 572 &sbb ("eax",0); # handle upmost overflow bit 573 &and ($tp,"eax"); 574 ¬ ("eax"); 575 &mov ($np,$rp); 576 &and ($np,"eax"); 577 &or ($tp,$np); # tp=carry?tp:rp 578 579&set_label("copy",16); # copy or in-place refresh 580 &mov ("eax",&DWP(0,$tp,$num,4)); 581 &mov (&DWP(0,$rp,$num,4),"eax"); # rp[i]=tp[i] 582 &mov (&DWP($frame,"esp",$num,4),$j); # zap temporary vector 583 &dec ($num); 584 &jge (&label("copy")); 585 586 &mov ("esp",$_sp); # pull saved stack pointer 587 &mov ("eax",1); 588&set_label("just_leave"); 589&function_end("bn_mul_mont"); 590 591&asciz("Montgomery Multiplication for x86, CRYPTOGAMS by <appro\@openssl.org>"); 592 593&asm_finish(); 594