2 # Copyright 1998-2016 The OpenSSL Project Authors. All Rights Reserved.
4 # Licensed under the Apache License 2.0 (the "License"). You may not use
5 # this file except in compliance with the License. You can obtain a copy
6 # in the file LICENSE in the source distribution or at
7 # https://www.openssl.org/source/license.html
10 # ====================================================================
11 # [Re]written by Andy Polyakov <appro@openssl.org> for the OpenSSL
12 # project. The module is, however, dual licensed under OpenSSL and
13 # CRYPTOGAMS licenses depending on where you obtain it. For further
14 # details see http://www.openssl.org/~appro/cryptogams/.
15 # ====================================================================
17 # At some point it became apparent that the original SSLeay RC4
18 # assembler implementation performs suboptimally on latest IA-32
19 # microarchitectures. After re-tuning performance has changed as
27 # (*) This number is actually a trade-off:-) It's possible to
28 # achieve +72%, but at the cost of -48% off PIII performance.
29 # In other words code performing further 13% faster on AMD
30 # would perform almost 2 times slower on Intel PIII...
31 # For reference! This code delivers ~80% of rc4-amd64.pl
32 # performance on the same Opteron machine.
33 # (**) This number requires compressed key schedule set up by
34 # RC4_set_key [see commentary below for further details].
38 # Optimize for Core2 and Westmere [and incidentally Opteron]. Current
39 # performance in cycles per processed byte (less is better) and
40 # improvement relative to previous version of this module is:
42 # Pentium 10.2 # original numbers
46 # Opteron 6.1/+20% # new MMX numbers
48 # Westmere 5.1/+94%(**)
49 # Sandy Bridge 5.0/+8%
55 # (*) PIII can actually deliver 6.6 cycles per byte with MMX code,
56 # but this specific code performs poorly on Core2. And vice
57 # versa, below MMX/SSE code delivering 5.8/7.1 on Core2 performs
58 # poorly on PIII, at 8.0/14.5:-( As PIII is not a "hot" CPU
59 # [anymore], I chose to discard PIII-specific code path and opt
60 # for original IALU-only code, which is why MMX/SSE code path
61 # is guarded by SSE2 bit (see below), not MMX/SSE.
62 # (**) Performance vs. block size on Core2 and Westmere had a maximum
63 # at ... 64 bytes block size. And it was quite a maximum, 40-60%
64 # in comparison to largest 8KB block size. Above improvement
65 # coefficients are for the largest block size.
67 $0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1;
68 push(@INC,"${dir}","${dir}../../perlasm");
71 $output = pop and open STDOUT,">$output";
73 &asm_init($ARGV[0],$x86only = $ARGV[$#ARGV] eq "386");
85 my $func = ($i==0)?*mov:*or;
87 &add (&LB($yy),&LB($tx));
88 &mov ($ty,&DWP(0,$dat,$yy,4));
89 &mov (&DWP(0,$dat,$yy,4),$tx);
90 &mov (&DWP(0,$dat,$xx,4),$ty);
94 &ror ($out,8) if ($i!=0);
96 &mov ($tx,&DWP(0,$dat,$xx,4));
98 &mov ($tx,&wparam(3)); # reload [re-biased] out
100 &$func ($out,&DWP(0,$dat,$ty,4));
104 # >20% faster on Atom and Sandy Bridge[!], 8% faster on Opteron,
105 # but ~40% slower on Core2 and Westmere... Attempt to add movz
106 # brings down Opteron by 25%, Atom and Sandy Bridge by 15%, yet
107 # on Core2 with movz it's almost 20% slower than below alternative
108 # code... Yes, it's a total mess...
110 $RC4_loop_mmx = sub { # SSE actually...
113 my $mm=$i<=0?"mm0":"mm".($i&1);
115 &add (&LB($yy),&LB($tx));
116 &lea (@XX[1],&DWP(1,@XX[0]));
117 &pxor ("mm2","mm0") if ($i==0);
118 &psllq ("mm1",8) if ($i==0);
120 &pxor ("mm0","mm0") if ($i<=0);
121 &mov ($ty,&DWP(0,$dat,$yy,4));
122 &mov (&DWP(0,$dat,$yy,4),$tx);
123 &pxor ("mm1","mm2") if ($i==0);
124 &mov (&DWP(0,$dat,$XX[0],4),$ty);
125 &add (&LB($ty),&LB($tx));
126 &movd (@XX[0],"mm7") if ($i==0);
127 &mov ($tx,&DWP(0,$dat,@XX[1],4));
128 &pxor ("mm1","mm1") if ($i==1);
129 &movq ("mm2",&QWP(0,$inp)) if ($i==1);
130 &movq (&QWP(-8,(@XX[0],$inp)),"mm1") if ($i==0);
131 &pinsrw ($mm,&DWP(0,$dat,$ty,4),$j);
133 push (@XX,shift(@XX)) if ($i>=0);
136 # Using pinsrw here improves performance on Intel CPUs by 2-3%, but
137 # brings down AMD by 7%...
138 $RC4_loop_mmx = sub {
141 &add (&LB($yy),&LB($tx));
142 &psllq ("mm1",8*(($i-1)&7)) if (abs($i)!=1);
143 &mov ($ty,&DWP(0,$dat,$yy,4));
144 &mov (&DWP(0,$dat,$yy,4),$tx);
145 &mov (&DWP(0,$dat,$xx,4),$ty);
148 &movz ($xx,&LB($xx)); # (*)
149 &movz ($ty,&LB($ty)); # (*)
150 &pxor ("mm2",$i==1?"mm0":"mm1") if ($i>=0);
151 &movq ("mm0",&QWP(0,$inp)) if ($i<=0);
152 &movq (&QWP(-8,($out,$inp)),"mm2") if ($i==0);
153 &mov ($tx,&DWP(0,$dat,$xx,4));
154 &movd ($i>0?"mm1":"mm2",&DWP(0,$dat,$ty,4));
156 # (*) This is the key to Core2 and Westmere performance.
157 # Without movz out-of-order execution logic confuses
158 # itself and fails to reorder loads and stores. Problem
159 # appears to be fixed in Sandy Bridge...
163 &external_label("OPENSSL_ia32cap_P");
165 # void RC4(RC4_KEY *key,size_t len,const unsigned char *inp,unsigned char *out);
166 &function_begin("RC4");
167 &mov ($dat,&wparam(0)); # load key schedule pointer
168 &mov ($ty, &wparam(1)); # load len
169 &mov ($inp,&wparam(2)); # load inp
170 &mov ($out,&wparam(3)); # load out
172 &xor ($xx,$xx); # avoid partial register stalls
175 &cmp ($ty,0); # safety net
176 &je (&label("abort"));
178 &mov (&LB($xx),&BP(0,$dat)); # load key->x
179 &mov (&LB($yy),&BP(4,$dat)); # load key->y
182 &lea ($tx,&DWP(0,$inp,$ty));
183 &sub ($out,$inp); # re-bias out
184 &mov (&wparam(1),$tx); # save input+len
188 # detect compressed key schedule...
189 &cmp (&DWP(256,$dat),-1);
190 &je (&label("RC4_CHAR"));
192 &mov ($tx,&DWP(0,$dat,$xx,4));
194 &and ($ty,-4); # how many 4-byte chunks?
195 &jz (&label("loop1"));
197 &mov (&wparam(3),$out); # $out as accumulator in these loops
199 &jmp (&label("go4loop4"));
202 &jz (&label("go4loop4"));
204 &picmeup($out,"OPENSSL_ia32cap_P");
205 &bt (&DWP(0,$out),26); # check SSE2 bit [could have been MMX]
206 &jnc (&label("go4loop4"));
208 &mov ($out,&wparam(3)) if (!$alt);
209 &movd ("mm7",&wparam(3)) if ($alt);
211 &lea ($ty,&DWP(-8,$inp,$ty));
212 &mov (&DWP(-4,$dat),$ty); # save input+(len/8)*8-8
215 &jmp(&label("loop_mmx_enter"));
217 &set_label("loop_mmx",16);
219 &set_label("loop_mmx_enter");
220 for ($i=1;$i<8;$i++) { &$RC4_loop_mmx($i); }
222 &xor ($yy,$yy); # this is second key to Core2
223 &mov (&LB($yy),&LB($ty)); # and Westmere performance...
224 &cmp ($inp,&DWP(-4,$dat));
225 &lea ($inp,&DWP(8,$inp));
226 &jb (&label("loop_mmx"));
233 &movq (&QWP(-8,$out,$inp),"mm1");
237 &movq (&QWP(-8,$out,$inp),"mm2");
241 &cmp ($inp,&wparam(1)); # compare to input+len
242 &je (&label("done"));
243 &jmp (&label("loop1"));
246 &set_label("go4loop4",16);
247 &lea ($ty,&DWP(-4,$inp,$ty));
248 &mov (&wparam(2),$ty); # save input+(len/4)*4-4
251 for ($i=0;$i<4;$i++) { RC4_loop($i); }
253 &xor ($out,&DWP(0,$inp));
254 &cmp ($inp,&wparam(2)); # compare to input+(len/4)*4-4
255 &mov (&DWP(0,$tx,$inp),$out);# $tx holds re-biased out here
256 &lea ($inp,&DWP(4,$inp));
257 &mov ($tx,&DWP(0,$dat,$xx,4));
258 &jb (&label("loop4"));
260 &cmp ($inp,&wparam(1)); # compare to input+len
261 &je (&label("done"));
262 &mov ($out,&wparam(3)); # restore $out
264 &set_label("loop1",16);
265 &add (&LB($yy),&LB($tx));
266 &mov ($ty,&DWP(0,$dat,$yy,4));
267 &mov (&DWP(0,$dat,$yy,4),$tx);
268 &mov (&DWP(0,$dat,$xx,4),$ty);
272 &mov ($ty,&DWP(0,$dat,$ty,4));
273 &xor (&LB($ty),&BP(0,$inp));
274 &lea ($inp,&DWP(1,$inp));
275 &mov ($tx,&DWP(0,$dat,$xx,4));
276 &cmp ($inp,&wparam(1)); # compare to input+len
277 &mov (&BP(-1,$out,$inp),&LB($ty));
278 &jb (&label("loop1"));
280 &jmp (&label("done"));
282 # this is essentially Intel P4 specific codepath...
283 &set_label("RC4_CHAR",16);
284 &movz ($tx,&BP(0,$dat,$xx));
285 # strangely enough unrolled loop performs over 20% slower...
286 &set_label("cloop1");
287 &add (&LB($yy),&LB($tx));
288 &movz ($ty,&BP(0,$dat,$yy));
289 &mov (&BP(0,$dat,$yy),&LB($tx));
290 &mov (&BP(0,$dat,$xx),&LB($ty));
291 &add (&LB($ty),&LB($tx));
292 &movz ($ty,&BP(0,$dat,$ty));
294 &xor (&LB($ty),&BP(0,$inp));
295 &lea ($inp,&DWP(1,$inp));
296 &movz ($tx,&BP(0,$dat,$xx));
297 &cmp ($inp,&wparam(1));
298 &mov (&BP(-1,$out,$inp),&LB($ty));
299 &jb (&label("cloop1"));
303 &mov (&DWP(-4,$dat),$yy); # save key->y
304 &mov (&BP(-8,$dat),&LB($xx)); # save key->x
306 &function_end("RC4");
308 ########################################################################
316 # void RC4_set_key(RC4_KEY *key,int len,const unsigned char *data);
317 &function_begin("RC4_set_key");
318 &mov ($out,&wparam(0)); # load key
319 &mov ($idi,&wparam(1)); # load len
320 &mov ($inp,&wparam(2)); # load data
321 &picmeup($idx,"OPENSSL_ia32cap_P");
323 &lea ($out,&DWP(2*4,$out)); # &key->data
324 &lea ($inp,&DWP(0,$inp,$idi)); # $inp to point at the end
327 &mov (&DWP(-4,$out),$idi); # borrow key->y
329 &bt (&DWP(0,$idx),20); # check for bit#20
330 &jc (&label("c1stloop"));
332 &set_label("w1stloop",16);
333 &mov (&DWP(0,$out,"eax",4),"eax"); # key->data[i]=i;
334 &add (&LB("eax"),1); # i++;
335 &jnc (&label("w1stloop"));
340 &set_label("w2ndloop",16);
341 &mov ("eax",&DWP(0,$out,$ido,4));
342 &add (&LB($idx),&BP(0,$inp,$idi));
343 &add (&LB($idx),&LB("eax"));
345 &mov ("ebx",&DWP(0,$out,$idx,4));
346 &jnz (&label("wnowrap"));
347 &mov ($idi,&DWP(-4,$out));
348 &set_label("wnowrap");
349 &mov (&DWP(0,$out,$idx,4),"eax");
350 &mov (&DWP(0,$out,$ido,4),"ebx");
352 &jnc (&label("w2ndloop"));
353 &jmp (&label("exit"));
355 # Unlike all other x86 [and x86_64] implementations, Intel P4 core
356 # [including EM64T] was found to perform poorly with above "32-bit" key
357 # schedule, a.k.a. RC4_INT. Performance improvement for IA-32 hand-coded
358 # assembler turned out to be 3.5x if re-coded for compressed 8-bit one,
359 # a.k.a. RC4_CHAR! It's however inappropriate to just switch to 8-bit
360 # schedule for x86[_64], because non-P4 implementations suffer from
361 # significant performance losses then, e.g. PIII exhibits >2x
362 # deterioration, and so does Opteron. In order to assure optimal
363 # all-round performance, we detect P4 at run-time and set up compressed
364 # key schedule, which is recognized by RC4 procedure.
366 &set_label("c1stloop",16);
367 &mov (&BP(0,$out,"eax"),&LB("eax")); # key->data[i]=i;
368 &add (&LB("eax"),1); # i++;
369 &jnc (&label("c1stloop"));
375 &set_label("c2ndloop",16);
376 &mov (&LB("eax"),&BP(0,$out,$ido));
377 &add (&LB($idx),&BP(0,$inp,$idi));
378 &add (&LB($idx),&LB("eax"));
380 &mov (&LB("ebx"),&BP(0,$out,$idx));
381 &jnz (&label("cnowrap"));
382 &mov ($idi,&DWP(-4,$out));
383 &set_label("cnowrap");
384 &mov (&BP(0,$out,$idx),&LB("eax"));
385 &mov (&BP(0,$out,$ido),&LB("ebx"));
387 &jnc (&label("c2ndloop"));
389 &mov (&DWP(256,$out),-1); # mark schedule as compressed
393 &mov (&DWP(-8,$out),"eax"); # key->x=0;
394 &mov (&DWP(-4,$out),"eax"); # key->y=0;
395 &function_end("RC4_set_key");
397 # const char *RC4_options(void);
398 &function_begin_B("RC4_options");
399 &call (&label("pic_point"));
400 &set_label("pic_point");
402 &lea ("eax",&DWP(&label("opts")."-".&label("pic_point"),"eax"));
403 &picmeup("edx","OPENSSL_ia32cap_P");
404 &mov ("edx",&DWP(0,"edx"));
406 &jc (&label("1xchar"));
408 &jnc (&label("ret"));
411 &set_label("1xchar");
415 &set_label("opts",64);
416 &asciz ("rc4(4x,int)");
417 &asciz ("rc4(1x,char)");
418 &asciz ("rc4(8x,mmx)");
419 &asciz ("RC4 for x86, CRYPTOGAMS by <appro\@openssl.org>");
421 &function_end_B("RC4_options");