Final touches to rc4/asm/rc4-596.pl, +52% better performance on AMD core.

#!/usr/local/bin/perl

# define for pentium pro friendly version

# At some point it became apparent that the original SSLeay RC4

# assembler implementation performs suboptimal 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 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>

push(@INC,"perlasm","../../perlasm");

require "x86asm.pl";

	# Moved out

	# &mov(	$tx,		&DWP(0,$d,$x,4)) if $p < 0;

	 &add(	$y,		$tx);

	&and(	$y,		0xff);

	 &inc(	$x);			# NEXT ROUND 

	&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);

	&and(	$x,		0xff);	# NEXT ROUND

	 &and(	$ty,		0xff);

	&mov(	&DWP(0,$d,$y,4),$tx);

	 &nop();

	&mov(	$ty,		&DWP(0,$d,$ty,4));

	 &and(	$ty,		0xff);

	&mov(	$tx,		&DWP(0,$d,$x,4)) if $p < 1; # NEXT ROUND

	 # XXX

	 &mov(	$ty,		&DWP(0,$d,$ty,4));

	if (!$char)

		{

	&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));

	&mov(	$x,	&DWP(0,$d,"",1));

	 &mov(	$y,	&DWP(4,$d,"",1));

	&movb(	&LB($x),	&BP(0,$d,"",1));

	 &movb(	&LB($y),	&BP(4,$d,"",1));

	&mov(	$out,	&wparam(3));

	 &inc(	$x);

	 &inc(	&LB($x));

	&stack_push(3);	# 3 temp variables

	 &add(	$d,	8);

	&and(	$x,		0xff);

	# detect compressed schedule, see commentary section in rc4_skey.c...

	&cmp(&DWP(256,$d),-1);

	&set_label("finished");

	&dec(	$x);

	 &stack_pop(3);

	&mov(	&DWP(-4,$d,"",0),$y);

	&movb(	&BP(-4,$d,"",0),&LB($y));

	 &movb(	&BP(-8,$d,"",0),&LB($x));

	&function_end($name);