#!/usr/bin/env perl## ====================================================================# Written by Andy Polyakov <appro@fy.chalmers.se> for the OpenSSL# project. Rights for redistribution and usage in source and binary# forms are granted according to the OpenSSL license.# ====================================================================## Unlike 0.9.7f this code expects RC4_CHAR back in config line! See# commentary section in corresponding script in development branch# for background information about this option carousel. For those# who don't have energy to figure out these gory details, here is# basis in form of performance matrix relative to the original# 0.9.7e C code-base:##		0.9.7e	0.9.7f	this# AMD64		1x	3.3x	2.4x# EM64T		1x	0.8x	1.5x## In other words idea is to trade -25% AMD64 performance to compensate# for deterioration and gain +90% on EM64T core. Development branch# maintains best performance for either target, i.e. 3.3x for AMD64# and 1.5x for EM64T.$output=shift;open STDOUT,">$output" || die "can't open $output: $!";$dat="%rdi";	    # arg1$len="%rsi";	    # arg2$inp="%rdx";	    # arg3$out="%rcx";	    # arg4@XX=("%r8","%r10");@TX=("%r9","%r11");$YY="%r12";$TY="%r13";$code=<<___;;.text.globl	RC4.type	RC4,\@function.align	16RC4:	or	$len,$len	jne	.Lentry	repret.Lentry:	push	%r12	push	%r13	add	\$2,$dat	movzb	-2($dat),$XX[0]#d	movzb	-1($dat),$YY#d	add	\$1,$XX[0]#b	movzb	($dat,$XX[0]),$TX[0]#d	test	\$-8,$len	jz	.Lcloop1	push	%rbx.align	16	# incidentally aligned already.Lcloop8:	mov	($inp),%eax	mov	4($inp),%ebx___# unroll 2x4-wise, because 64-bit rotates kill Intel P4...for ($i=0;$i<4;$i++) {$code.=<<___;	add	$TX[0]#b,$YY#b	lea	1($XX[0]),$XX[1]	movzb	($dat,$YY),$TY#d	movzb	$XX[1]#b,$XX[1]#d	movzb	($dat,$XX[1]),$TX[1]#d	movb	$TX[0]#b,($dat,$YY)	cmp	$XX[1],$YY	movb	$TY#b,($dat,$XX[0])	jne	.Lcmov$i			# Intel cmov is sloooow...	mov	$TX[0],$TX[1].Lcmov$i:	add	$TX[0]#b,$TY#b	xor	($dat,$TY),%al	ror	\$8,%eax___push(@TX,shift(@TX)); push(@XX,shift(@XX));	# "rotate" registers}for ($i=4;$i<8;$i++) {$code.=<<___;	add	$TX[0]#b,$YY#b	lea	1($XX[0]),$XX[1]	movzb	($dat,$YY),$TY#d	movzb	$XX[1]#b,$XX[1]#d	movzb	($dat,$XX[1]),$TX[1]#d	movb	$TX[0]#b,($dat,$YY)	cmp	$XX[1],$YY	movb	$TY#b,($dat,$XX[0])	jne	.Lcmov$i			# Intel cmov is sloooow...	mov	$TX[0],$TX[1].Lcmov$i:	add	$TX[0]#b,$TY#b	xor	($dat,$TY),%bl	ror	\$8,%ebx___push(@TX,shift(@TX)); push(@XX,shift(@XX));	# "rotate" registers}$code.=<<___;	lea	-8($len),$len	mov	%eax,($out)	lea	8($inp),$inp	mov	%ebx,4($out)	lea	8($out),$out	test	\$-8,$len	jnz	.Lcloop8	pop	%rbx	cmp	\$0,$len	jne	.Lcloop1.Lexit:	sub	\$1,$XX[0]#b	movb	$XX[0]#b,-2($dat)	movb	$YY#b,-1($dat)	pop	%r13	pop	%r12	repret.align	16.Lcloop1:	add	$TX[0]#b,$YY#b	movzb	($dat,$YY),$TY#d	movb	$TX[0]#b,($dat,$YY)	movb	$TY#b,($dat,$XX[0])	add	$TX[0]#b,$TY#b	add	\$1,$XX[0]#b	movzb	($dat,$TY),$TY#d	movzb	($dat,$XX[0]),$TX[0]#d	xorb	($inp),$TY#b	lea	1($inp),$inp	movb	$TY#b,($out)	lea	1($out),$out	sub	\$1,$len	jnz	.Lcloop1	jmp	.Lexit.size	RC4,.-RC4___$code =~ s/#([bwd])/$1/gm;$code =~ s/repret/.byte\t0xF3,0xC3/gm;print $code;