--- /dev/null
+#!/usr/bin/env perl
+
+# ====================================================================
+# [Re]written by Andy Polyakov <appro@fy.chalmers.se> for the OpenSSL
+# project. The module is, however, dual licensed under OpenSSL and
+# CRYPTOGAMS licenses depending on where you obtain it. For further
+# details see http://www.openssl.org/~appro/cryptogams/.
+# ====================================================================
+
+# At some point it became apparent that the original SSLeay RC4
+# assembler implementation performs suboptimally on latest IA-32
+# microarchitectures. After re-tuning performance has changed as
+# following:
+#
+# Pentium -10%
+# Pentium III +12%
+# AMD +50%(*)
+# P4 +250%(**)
+#
+# (*) This number is actually a trade-off:-) It's possible to
+# achieve +72%, but at the cost of -48% off PIII performance.
+# In other words code performing further 13% faster on AMD
+# would perform almost 2 times slower on Intel PIII...
+# For reference! This code delivers ~80% of rc4-amd64.pl
+# performance on the same Opteron machine.
+# (**) This number requires compressed key schedule set up by
+# RC4_set_key [see commentary below for further details].
+#
+# <appro@fy.chalmers.se>
+
+# May 2011
+#
+# Optimize for Core2 and Westmere [and incidentally Opteron]. Current
+# performance in cycles per processed byte (less is better) and
+# improvement relative to previous version of this module is:
+#
+# Pentium 10.2 # original numbers
+# Pentium III 7.8(*)
+# Intel P4 7.5
+#
+# Opteron 6.1/+20% # new MMX numbers
+# Core2 5.3/+67%(**)
+# Westmere 5.1/+94%(**)
+# Sandy Bridge 5.0/+8%
+# Atom 12.6/+6%
+#
+# (*) PIII can actually deliver 6.6 cycles per byte with MMX code,
+# but this specific code performs poorly on Core2. And vice
+# versa, below MMX/SSE code delivering 5.8/7.1 on Core2 performs
+# poorly on PIII, at 8.0/14.5:-( As PIII is not a "hot" CPU
+# [anymore], I chose to discard PIII-specific code path and opt
+# for original IALU-only code, which is why MMX/SSE code path
+# is guarded by SSE2 bit (see below), not MMX/SSE.
+# (**) Performance vs. block size on Core2 and Westmere had a maximum
+# at ... 64 bytes block size. And it was quite a maximum, 40-60%
+# in comparison to largest 8KB block size. Above improvement
+# coefficients are for the largest block size.
+
+$0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1;
+push(@INC,"${dir}","${dir}../../perlasm");
+require "x86asm.pl";
+
+&asm_init($ARGV[0],"rc4-586.pl");
+
+$xx="eax";
+$yy="ebx";
+$tx="ecx";
+$ty="edx";
+$inp="esi";
+$out="ebp";
+$dat="edi";
+
+sub RC4_loop {
+ my $i=shift;
+ my $func = ($i==0)?*mov:*or;
+
+ &add (&LB($yy),&LB($tx));
+ &mov ($ty,&DWP(0,$dat,$yy,4));
+ &mov (&DWP(0,$dat,$yy,4),$tx);
+ &mov (&DWP(0,$dat,$xx,4),$ty);
+ &add ($ty,$tx);
+ &inc (&LB($xx));
+ &and ($ty,0xff);
+ &ror ($out,8) if ($i!=0);
+ if ($i<3) {
+ &mov ($tx,&DWP(0,$dat,$xx,4));
+ } else {
+ &mov ($tx,&wparam(3)); # reload [re-biased] out
+ }
+ &$func ($out,&DWP(0,$dat,$ty,4));
+}
+
+if ($alt=0) {
+ # >20% faster on Atom and Sandy Bridge[!], 8% faster on Opteron,
+ # but ~40% slower on Core2 and Westmere... Attempt to add movz
+ # brings down Opteron by 25%, Atom and Sandy Bridge by 15%, yet
+ # on Core2 with movz it's almost 20% slower than below alternative
+ # code... Yes, it's a total mess...
+ my @XX=($xx,$out);
+ $RC4_loop_mmx = sub { # SSE actually...
+ my $i=shift;
+ my $j=$i<=0?0:$i>>1;
+ my $mm=$i<=0?"mm0":"mm".($i&1);
+
+ &add (&LB($yy),&LB($tx));
+ &lea (@XX[1],&DWP(1,@XX[0]));
+ &pxor ("mm2","mm0") if ($i==0);
+ &psllq ("mm1",8) if ($i==0);
+ &and (@XX[1],0xff);
+ &pxor ("mm0","mm0") if ($i<=0);
+ &mov ($ty,&DWP(0,$dat,$yy,4));
+ &mov (&DWP(0,$dat,$yy,4),$tx);
+ &pxor ("mm1","mm2") if ($i==0);
+ &mov (&DWP(0,$dat,$XX[0],4),$ty);
+ &add (&LB($ty),&LB($tx));
+ &movd (@XX[0],"mm7") if ($i==0);
+ &mov ($tx,&DWP(0,$dat,@XX[1],4));
+ &pxor ("mm1","mm1") if ($i==1);
+ &movq ("mm2",&QWP(0,$inp)) if ($i==1);
+ &movq (&QWP(-8,(@XX[0],$inp)),"mm1") if ($i==0);
+ &pinsrw ($mm,&DWP(0,$dat,$ty,4),$j);
+
+ push (@XX,shift(@XX)) if ($i>=0);
+ }
+} else {
+ # Using pinsrw here improves performane on Intel CPUs by 2-3%, but
+ # brings down AMD by 7%...
+ $RC4_loop_mmx = sub {
+ my $i=shift;
+
+ &add (&LB($yy),&LB($tx));
+ &psllq ("mm1",8*(($i-1)&7)) if (abs($i)!=1);
+ &mov ($ty,&DWP(0,$dat,$yy,4));
+ &mov (&DWP(0,$dat,$yy,4),$tx);
+ &mov (&DWP(0,$dat,$xx,4),$ty);
+ &inc ($xx);
+ &add ($ty,$tx);
+ &movz ($xx,&LB($xx)); # (*)
+ &movz ($ty,&LB($ty)); # (*)
+ &pxor ("mm2",$i==1?"mm0":"mm1") if ($i>=0);
+ &movq ("mm0",&QWP(0,$inp)) if ($i<=0);
+ &movq (&QWP(-8,($out,$inp)),"mm2") if ($i==0);
+ &mov ($tx,&DWP(0,$dat,$xx,4));
+ &movd ($i>0?"mm1":"mm2",&DWP(0,$dat,$ty,4));
+
+ # (*) This is the key to Core2 and Westmere performance.
+ # Whithout movz out-of-order execution logic confuses
+ # itself and fails to reorder loads and stores. Problem
+ # appears to be fixed in Sandy Bridge...
+ }
+}
+
+&external_label("OPENSSL_ia32cap_P");
+
+# void RC4(RC4_KEY *key,size_t len,const unsigned char *inp,unsigned char *out);
+&function_begin("RC4");
+ &mov ($dat,&wparam(0)); # load key schedule pointer
+ &mov ($ty, &wparam(1)); # load len
+ &mov ($inp,&wparam(2)); # load inp
+ &mov ($out,&wparam(3)); # load out
+
+ &xor ($xx,$xx); # avoid partial register stalls
+ &xor ($yy,$yy);
+
+ &cmp ($ty,0); # safety net
+ &je (&label("abort"));
+
+ &mov (&LB($xx),&BP(0,$dat)); # load key->x
+ &mov (&LB($yy),&BP(4,$dat)); # load key->y
+ &add ($dat,8);
+
+ &lea ($tx,&DWP(0,$inp,$ty));
+ &sub ($out,$inp); # re-bias out
+ &mov (&wparam(1),$tx); # save input+len
+
+ &inc (&LB($xx));
+
+ # detect compressed key schedule...
+ &cmp (&DWP(256,$dat),-1);
+ &je (&label("RC4_CHAR"));
+
+ &mov ($tx,&DWP(0,$dat,$xx,4));
+
+ &and ($ty,-4); # how many 4-byte chunks?
+ &jz (&label("loop1"));
+
+ &test ($ty,-8);
+ &mov (&wparam(3),$out); # $out as accumulator in these loops
+ &jz (&label("go4loop4"));
+
+ &picmeup($out,"OPENSSL_ia32cap_P");
+ &bt (&DWP(0,$out),26); # check SSE2 bit [could have been MMX]
+ &jnc (&label("go4loop4"));
+
+ &mov ($out,&wparam(3)) if (!$alt);
+ &movd ("mm7",&wparam(3)) if ($alt);
+ &and ($ty,-8);
+ &lea ($ty,&DWP(-8,$inp,$ty));
+ &mov (&DWP(-4,$dat),$ty); # save input+(len/8)*8-8
+
+ &$RC4_loop_mmx(-1);
+ &jmp(&label("loop_mmx_enter"));
+
+ &set_label("loop_mmx",16);
+ &$RC4_loop_mmx(0);
+ &set_label("loop_mmx_enter");
+ for ($i=1;$i<8;$i++) { &$RC4_loop_mmx($i); }
+ &mov ($ty,$yy);
+ &xor ($yy,$yy); # this is second key to Core2
+ &mov (&LB($yy),&LB($ty)); # and Westmere performance...
+ &cmp ($inp,&DWP(-4,$dat));
+ &lea ($inp,&DWP(8,$inp));
+ &jb (&label("loop_mmx"));
+
+ if ($alt) {
+ &movd ($out,"mm7");
+ &pxor ("mm2","mm0");
+ &psllq ("mm1",8);
+ &pxor ("mm1","mm2");
+ &movq (&QWP(-8,$out,$inp),"mm1");
+ } else {
+ &psllq ("mm1",56);
+ &pxor ("mm2","mm1");
+ &movq (&QWP(-8,$out,$inp),"mm2");
+ }
+ &emms ();
+
+ &cmp ($inp,&wparam(1)); # compare to input+len
+ &je (&label("done"));
+ &jmp (&label("loop1"));
+
+&set_label("go4loop4",16);
+ &lea ($ty,&DWP(-4,$inp,$ty));
+ &mov (&wparam(2),$ty); # save input+(len/4)*4-4
+
+ &set_label("loop4");
+ for ($i=0;$i<4;$i++) { RC4_loop($i); }
+ &ror ($out,8);
+ &xor ($out,&DWP(0,$inp));
+ &cmp ($inp,&wparam(2)); # compare to input+(len/4)*4-4
+ &mov (&DWP(0,$tx,$inp),$out);# $tx holds re-biased out here
+ &lea ($inp,&DWP(4,$inp));
+ &mov ($tx,&DWP(0,$dat,$xx,4));
+ &jb (&label("loop4"));
+
+ &cmp ($inp,&wparam(1)); # compare to input+len
+ &je (&label("done"));
+ &mov ($out,&wparam(3)); # restore $out
+
+ &set_label("loop1",16);
+ &add (&LB($yy),&LB($tx));
+ &mov ($ty,&DWP(0,$dat,$yy,4));
+ &mov (&DWP(0,$dat,$yy,4),$tx);
+ &mov (&DWP(0,$dat,$xx,4),$ty);
+ &add ($ty,$tx);
+ &inc (&LB($xx));
+ &and ($ty,0xff);
+ &mov ($ty,&DWP(0,$dat,$ty,4));
+ &xor (&LB($ty),&BP(0,$inp));
+ &lea ($inp,&DWP(1,$inp));
+ &mov ($tx,&DWP(0,$dat,$xx,4));
+ &cmp ($inp,&wparam(1)); # compare to input+len
+ &mov (&BP(-1,$out,$inp),&LB($ty));
+ &jb (&label("loop1"));
+
+ &jmp (&label("done"));
+
+# this is essentially Intel P4 specific codepath...
+&set_label("RC4_CHAR",16);
+ &movz ($tx,&BP(0,$dat,$xx));
+ # strangely enough unrolled loop performs over 20% slower...
+ &set_label("cloop1");
+ &add (&LB($yy),&LB($tx));
+ &movz ($ty,&BP(0,$dat,$yy));
+ &mov (&BP(0,$dat,$yy),&LB($tx));
+ &mov (&BP(0,$dat,$xx),&LB($ty));
+ &add (&LB($ty),&LB($tx));
+ &movz ($ty,&BP(0,$dat,$ty));
+ &add (&LB($xx),1);
+ &xor (&LB($ty),&BP(0,$inp));
+ &lea ($inp,&DWP(1,$inp));
+ &movz ($tx,&BP(0,$dat,$xx));
+ &cmp ($inp,&wparam(1));
+ &mov (&BP(-1,$out,$inp),&LB($ty));
+ &jb (&label("cloop1"));
+
+&set_label("done");
+ &dec (&LB($xx));
+ &mov (&DWP(-4,$dat),$yy); # save key->y
+ &mov (&BP(-8,$dat),&LB($xx)); # save key->x
+&set_label("abort");
+&function_end("RC4");
+
+########################################################################
+
+$inp="esi";
+$out="edi";
+$idi="ebp";
+$ido="ecx";
+$idx="edx";
+
+# void RC4_set_key(RC4_KEY *key,int len,const unsigned char *data);
+&function_begin("private_RC4_set_key");
+ &mov ($out,&wparam(0)); # load key
+ &mov ($idi,&wparam(1)); # load len
+ &mov ($inp,&wparam(2)); # load data
+ &picmeup($idx,"OPENSSL_ia32cap_P");
+
+ &lea ($out,&DWP(2*4,$out)); # &key->data
+ &lea ($inp,&DWP(0,$inp,$idi)); # $inp to point at the end
+ &neg ($idi);
+ &xor ("eax","eax");
+ &mov (&DWP(-4,$out),$idi); # borrow key->y
+
+ &bt (&DWP(0,$idx),20); # check for bit#20
+ &jc (&label("c1stloop"));
+
+&set_label("w1stloop",16);
+ &mov (&DWP(0,$out,"eax",4),"eax"); # key->data[i]=i;
+ &add (&LB("eax"),1); # i++;
+ &jnc (&label("w1stloop"));
+
+ &xor ($ido,$ido);
+ &xor ($idx,$idx);
+
+&set_label("w2ndloop",16);
+ &mov ("eax",&DWP(0,$out,$ido,4));
+ &add (&LB($idx),&BP(0,$inp,$idi));
+ &add (&LB($idx),&LB("eax"));
+ &add ($idi,1);
+ &mov ("ebx",&DWP(0,$out,$idx,4));
+ &jnz (&label("wnowrap"));
+ &mov ($idi,&DWP(-4,$out));
+ &set_label("wnowrap");
+ &mov (&DWP(0,$out,$idx,4),"eax");
+ &mov (&DWP(0,$out,$ido,4),"ebx");
+ &add (&LB($ido),1);
+ &jnc (&label("w2ndloop"));
+&jmp (&label("exit"));
+
+# Unlike all other x86 [and x86_64] implementations, Intel P4 core
+# [including EM64T] was found to perform poorly with above "32-bit" key
+# schedule, a.k.a. RC4_INT. Performance improvement for IA-32 hand-coded
+# assembler turned out to be 3.5x if re-coded for compressed 8-bit one,
+# a.k.a. RC4_CHAR! It's however inappropriate to just switch to 8-bit
+# schedule for x86[_64], because non-P4 implementations suffer from
+# significant performance losses then, e.g. PIII exhibits >2x
+# deterioration, and so does Opteron. In order to assure optimal
+# all-round performance, we detect P4 at run-time and set up compressed
+# key schedule, which is recognized by RC4 procedure.
+
+&set_label("c1stloop",16);
+ &mov (&BP(0,$out,"eax"),&LB("eax")); # key->data[i]=i;
+ &add (&LB("eax"),1); # i++;
+ &jnc (&label("c1stloop"));
+
+ &xor ($ido,$ido);
+ &xor ($idx,$idx);
+ &xor ("ebx","ebx");
+
+&set_label("c2ndloop",16);
+ &mov (&LB("eax"),&BP(0,$out,$ido));
+ &add (&LB($idx),&BP(0,$inp,$idi));
+ &add (&LB($idx),&LB("eax"));
+ &add ($idi,1);
+ &mov (&LB("ebx"),&BP(0,$out,$idx));
+ &jnz (&label("cnowrap"));
+ &mov ($idi,&DWP(-4,$out));
+ &set_label("cnowrap");
+ &mov (&BP(0,$out,$idx),&LB("eax"));
+ &mov (&BP(0,$out,$ido),&LB("ebx"));
+ &add (&LB($ido),1);
+ &jnc (&label("c2ndloop"));
+
+ &mov (&DWP(256,$out),-1); # mark schedule as compressed
+
+&set_label("exit");
+ &xor ("eax","eax");
+ &mov (&DWP(-8,$out),"eax"); # key->x=0;
+ &mov (&DWP(-4,$out),"eax"); # key->y=0;
+&function_end("private_RC4_set_key");
+
+# const char *RC4_options(void);
+&function_begin_B("RC4_options");
+ &call (&label("pic_point"));
+&set_label("pic_point");
+ &blindpop("eax");
+ &lea ("eax",&DWP(&label("opts")."-".&label("pic_point"),"eax"));
+ &picmeup("edx","OPENSSL_ia32cap_P");
+ &mov ("edx",&DWP(0,"edx"));
+ &bt ("edx",20);
+ &jc (&label("1xchar"));
+ &bt ("edx",26);
+ &jnc (&label("ret"));
+ &add ("eax",25);
+ &ret ();
+&set_label("1xchar");
+ &add ("eax",12);
+&set_label("ret");
+ &ret ();
+&set_label("opts",64);
+&asciz ("rc4(4x,int)");
+&asciz ("rc4(1x,char)");
+&asciz ("rc4(8x,mmx)");
+&asciz ("RC4 for x86, CRYPTOGAMS by <appro\@openssl.org>");
+&align (64);
+&function_end_B("RC4_options");
+
+&asm_finish();
+
projects / cassiopeia.git / blobdiff