<?php

$d = "4653896912";
$b = "13";
$z = hexdec(80000000);
print "1: $z\n";
if($z & $d){
	$d = ($d>>1);
	$d &= (~$z);
	$d |= 0x40000000;
	$d = ($d>>($b-1));
}else{
	$d = ($d>>$b);
}
print "2: $d\n";
?> 

#!/usr/bin/perl

$d = "4653896912";
$b = "13";
$z = hex(80000000);
print "1: $z\n";
if($z & $d){
	$d = ($d>>1);
	$d &= (~$z);
	$d |= 0x40000000;
	$d = ($d>>($b-1));
}else{
	$d = ($d>>$b);
}
print "2: $d\n";
exit;

$d = "4653896912";
$b = "13";
                                                                                
print "1: ",hex(80000000),"\n";
                                                                                
# ehemals im if-block                                                           
    print "2: $d vor erstem right shift (p.95 camel book)\n";
    $d = ($d>>1);
    print "2: $d nach erstem und vor zweitem right shift (p.95 camel book)\n";
    $d = ($d>>($b-1));
# /ehemals im if-block
                                                                                
print "2: $d\n";