crypto/cast/asm/cast-586.pl: +5% on PIII and remove obsolete readme.

#!/usr/local/bin/perl

# define for pentium pro friendly version

# This flag makes the inner loop one cycle longer, but generates 

# code that runs %30 faster on the pentium pro/II, 44% faster

# of PIII, while only %7 slower on the pentium.

# By default, this flag is on.

$ppro=1;

$0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1;

    &rotl(	$tmp4,		&LB($tmp1));

    if ($ppro) {

	&mov(	$tmp2,		$tmp4);		# B

	&xor(	$tmp1,		$tmp1);

	&mov(	$tmp2,		0xff);

	&movb(	&LB($tmp1),	&HB($tmp4));	# A

	&and(	$tmp2,		0xff);

	&and(	$tmp2,		$tmp4);

	&shr(	$tmp4,		16); 		#

	&xor(	$tmp3,		$tmp3);

There is a ppro flag in cast-586 which turns on/off

generation of pentium pro/II friendly code

This flag makes the inner loop one cycle longer, but generates 

code that runs %30 faster on the pentium pro/II, while only %7 slower

on the pentium.  By default, this flag is on.