#!/usr/local/bin/perl# At some point it became apparent that the original SSLeay RC4# assembler implementation performs suboptimaly on latest IA-32# microarchitectures. After re-tuning performance has changed as# following:## Pentium	+0%# Pentium III	+17%# AMD		+52%(*)# P4		+180%(**)## (*)	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 and therefore doesn't apply to 0.9.7 [option for#	compressed key schedule is implemented in 0.9.8 and later,#	see commentary section in rc4_skey.c for further details].##					<appro@fy.chalmers.se>push(@INC,"perlasm","../../perlasm");require "x86asm.pl";&asm_init($ARGV[0],"rc4-586.pl");$x="eax";$y="ebx";$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));	&mov(	$ty,		&DWP(0,$d,$y,4));	 # XXX	&mov(	&DWP(0,$d,$x,4),$ty);	 &add(	$ty,		$tx);	&mov(	&DWP(0,$d,$y,4),$tx);	 &and(	$ty,		0xff);	 &inc(	&LB($x));			# NEXT ROUND	&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));		}	}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(	$d,	8);	# detect compressed schedule, see commentary section in rc4_skey.c...	# in 0.9.7 context ~50 bytes below RC4_CHAR label remain redundant,	# as compressed key schedule is set up in 0.9.8 and later.	&cmp(&DWP(256,$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,	$ty);	 &jbe(&label("start"));	&set_label("end");	# There is quite a bit of extra crap in RC4_loop() for this	# first round	&RC4_loop(0,-1,1);	&RC4_loop(1,0,1);	&RC4_loop(2,0,1);	&RC4_loop(3,0,1);	&RC4_loop(4,0,1);	&RC4_loop(5,0,1);	&RC4_loop(6,1,1);	&jmp(&label("finished"));	&align(16);	# this is essentially Intel P4 specific codepath, see rc4_skey.c,	# and is engaged in 0.9.8 and later context...	&set_label("RC4_CHAR");	&lea	($ty,&DWP(0,$in,$ty));	&mov	(&swtmp(2),$ty);	# strangely enough unrolled loop performs over 20% slower...	&set_label("RC4_CHAR_loop");		&movz	($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($ty));		&add	(&LB($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);	}