Fix grammar in certificates.txt
[openssl.git] / crypto / rc4 / asm / rc4-586.pl
index 977a9f1237f2d00010302d7e4d16c4142cb3973e..1fae93ae1a7026051a6343701ab9e8f276758312 100644 (file)
-#!/usr/local/bin/perl
+#! /usr/bin/env perl
+# Copyright 1998-2020 The OpenSSL Project Authors. All Rights Reserved.
+#
+# Licensed under the Apache License 2.0 (the "License").  You may not use
+# this file except in compliance with the License.  You can obtain a copy
+# in the file LICENSE in the source distribution or at
+# https://www.openssl.org/source/license.html
+
+
+# ====================================================================
+# [Re]written by Andy Polyakov <appro@openssl.org> 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 suboptimal on latest IA-32
+# assembler implementation performs suboptimally on latest IA-32
 # microarchitectures. After re-tuning performance has changed as
 # following:
 #
-# Pentium      +0%
-# Pentium III  +17%
-# AMD          +52%(*)
-# P4           +180%(**)
+# 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 same Opteron machine.
+#      performance on the same Opteron machine.
 # (**) This number requires compressed key schedule set up by
-#      RC4_set_key, see commentary section in rc4_skey.c for
-#      further details.
-#                                      <appro@fy.chalmers.se>
+#      RC4_set_key [see commentary below for further details].
 
-push(@INC,"perlasm","../../perlasm");
+# 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%
+# VIA Nano     6.4/+9%
+# Ivy Bridge   4.9/±0%
+# Bulldozer    4.9/+15%
+#
+# (*)  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($ARGV[0],"rc4-586.pl");
+$output = pop and open STDOUT,">$output";
+
+&asm_init($ARGV[0],$x86only = $ARGV[$#ARGV] eq "386");
 
-$x="eax";
-$y="ebx";
+$xx="eax";
+$yy="ebx";
 $tx="ecx";
 $ty="edx";
-$in="esi";
-$out="edi";
-$d="ebp";
-
-&RC4("RC4");
-
-&asm_finish();
-
-sub RC4_loop
-       {
-       local($n,$p,$char)=@_;
-
-       &comment("Round $n");
-
-       if ($char)
-               {
-               if ($p >= 0)
-                       {
-                        &mov($ty,      &swtmp(2));
-                       &cmp($ty,       $in);
-                        &jbe(&label("finished"));
-                       &inc($in);
-                       }
-               else
-                       {
-                       &add($ty,       8);
-                        &inc($in);
-                       &cmp($ty,       $in);
-                        &jb(&label("finished"));
-                       &mov(&swtmp(2), $ty);
-                       }
-               }
-       # Moved out
-       # &mov( $tx,            &DWP(0,$d,$x,4)) if $p < 0;
-
-       &add(   &LB($y),        &LB($tx));
-        &inc(  &LB($x));                       # NEXT ROUND
-       &mov(   $ty,            &DWP(0,$d,$y,4));
-        # XXX
-       &mov(   &DWP(-4,$d,$x,4),$ty);                  # AGI
-        &add(  $ty,            $tx);
-       &mov(   &DWP(0,$d,$y,4),$tx);
-        &and(  $ty,            0xff);
-       &mov(   $tx,            &DWP(0,$d,$x,4)) if $p < 1; # NEXT ROUND
-        &mov(  $ty,            &DWP(0,$d,$ty,4));
-
-       if (!$char)
-               {
-               #moved up into last round
-               if ($p >= 1)
-                       {
-                       &add(   $out,   8)
-                       }
-               &movb(  &BP($n,"esp","",0),     &LB($ty));
-               }
-       else
-               {
-               # Note in+=8 has occured
-               &movb(  &HB($ty),       &BP(-1,$in,"",0));
-                # XXX
-               &xorb(&LB($ty),         &HB($ty));
-                # XXX
-               &movb(&BP($n,$out,"",0),&LB($ty));
-               }
+$inp="esi";
+$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
        }
-
-
-sub RC4
-       {
-       local($name)=@_;
-
-       &function_begin_B($name,"");
-
-       &mov($ty,&wparam(1));           # len
-       &cmp($ty,0);
-       &jne(&label("proceed"));
-       &ret();
-       &set_label("proceed");
-
-       &comment("");
-
-       &push("ebp");
-        &push("ebx");
-       &push("esi");
-        &xor(  $x,     $x);            # avoid partial register stalls
-       &push("edi");
-        &xor(  $y,     $y);            # avoid partial register stalls
-       &mov(   $d,     &wparam(0));    # key
-        &mov(  $in,    &wparam(2));
-
-       &movb(  &LB($x),        &BP(0,$d,"",1));
-        &movb( &LB($y),        &BP(4,$d,"",1));
-
-       &mov(   $out,   &wparam(3));
-        &inc(  &LB($x));
-
-       &stack_push(3); # 3 temp variables
-        &add(  $d,     8);
-
-       # detect compressed schedule, see commentary section in rc4_skey.c...
-       &cmp(&DWP(256,$d),-1);
-       &je(&label("RC4_CHAR"));
-
-        &lea(  $ty,    &DWP(-8,$ty,$in));
-
-       # check for 0 length input
-
-        &mov(  &swtmp(2),      $ty);   # this is now address to exit at
-       &mov(   $tx,    &DWP(0,$d,$x,4));
-
-        &cmp(  $ty,    $in);
-       &jb(    &label("end")); # less than 8 bytes
-
-       &set_label("start");
-
-       # filling DELAY SLOT
-       &add(   $in,    8);
-
-       &RC4_loop(0,-1,0);
-       &RC4_loop(1,0,0);
-       &RC4_loop(2,0,0);
-       &RC4_loop(3,0,0);
-       &RC4_loop(4,0,0);
-       &RC4_loop(5,0,0);
-       &RC4_loop(6,0,0);
-       &RC4_loop(7,1,0);
-       
-       &comment("apply the cipher text");
-       # xor the cipher data with input
-
-       #&add(  $out,   8); #moved up into last round
-
-       &mov(   $tx,    &swtmp(0));
-        &mov(  $ty,    &DWP(-8,$in,"",0));
-       &xor(   $tx,    $ty);
-        &mov(  $ty,    &DWP(-4,$in,"",0)); 
-       &mov(   &DWP(-8,$out,"",0),     $tx);
-        &mov(  $tx,    &swtmp(1));
-       &xor(   $tx,    $ty);
-        &mov(  $ty,    &swtmp(2));     # load end ptr;
-       &mov(   &DWP(-4,$out,"",0),     $tx);
-        &mov(  $tx,            &DWP(0,$d,$x,4));
-       &cmp($in,       $ty);
-        &jbe(&label("start"));
-
-       &set_label("end");
-
-       # There is quite a bit of extra crap in RC4_loop() for this
-       # first round
-       &RC4_loop(0,-1,1);
-       &RC4_loop(1,0,1);
-       &RC4_loop(2,0,1);
-       &RC4_loop(3,0,1);
-       &RC4_loop(4,0,1);
-       &RC4_loop(5,0,1);
-       &RC4_loop(6,1,1);
-
-       &jmp(&label("finished"));
-
-       &align(16);
-       # this is essentially Intel P4 specific codepath, see rc4_skey.c...
-       &set_label("RC4_CHAR");
-
-       &lea    ($ty,&DWP(0,$in,$ty));
-       &mov    (&swtmp(2),$ty);
-
+       &$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 performance 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.
+       #       Without 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"));
+
+       &mov    (&wparam(3),$out);      # $out as accumulator in these loops
+                                       if ($x86only) {
+       &jmp    (&label("go4loop4"));
+                                       } else {
+       &test   ($ty,-8);
+       &jz     (&label("go4loop4"));
+
+       &picmeup($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,$xx));
        # strangely enough unrolled loop performs over 20% slower...
-       &set_label("RC4_CHAR_loop");
-               &movz   ($tx,&BP(0,$d,$x));
-               &add    (&LB($y),&LB($tx));
-               &movz   ($ty,&BP(0,$d,$y));
-               &movb   (&BP(0,$d,$y),&LB($tx));
-               &movb   (&BP(0,$d,$x),&LB($ty));
+       &set_label("cloop1");
+               &add    (&LB($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   ($ty,&BP(0,$d,$ty));
-               &xorb   (&LB($ty),&BP(0,$in));
-               &movb   (&BP(0,$out),&LB($ty));
-               &inc    (&LB($x));
-               &inc    ($in);
-               &inc    ($out);
-               &cmp    ($in,&swtmp(2));
-       &jb     (&label("RC4_CHAR_loop"));
-
-       &set_label("finished");
-       &dec(   $x);
-        &stack_pop(3);
-       &movb(  &BP(-4,$d,"",0),&LB($y));
-        &movb( &BP(-8,$d,"",0),&LB($x));
-
-       &function_end($name);
-       }
+               &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";
+$idx="edx";
+
+# void RC4_set_key(RC4_KEY *key,int len,const unsigned char *data);
+&function_begin("RC4_set_key");
+       &mov    ($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("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();
 
+close STDOUT or die "error closing STDOUT: $!";