#!perl -w
use strict;
use IO::File;
use Getopt::Long;
my $xrefdwords;
GetOptions(
    "d"=>\$xrefdwords
);

for my $fn (@ARGV) {
    my $fh=(defined $fn && $fn ne "-" ) ? IO::File->new($fn, "r") : *STDIN;
    if (!$fh) { die "$fn: $!\n"; }
    binmode $fh;

    local $/;
    my $data=<$fh>;

    printf("----- %s\n", $fn);
    xrefdata($data);
}

sub xrefdata {
    my $data= shift;
    my @byteref;
    my @wordref;
    my @dwordref;
    for (my $i=0 ; $i<length($data) ; $i++)
    {
        my $b= ord(substr($data, $i, 1));
        my $w= unpack("v", substr($data, $i, 2));
        my $d= unpack("V", substr($data, $i, 4));
        $byteref[$i&3][$b]++;
        $byteref[4+($i&1)][$b]++;
        $byteref[6][$b]++;

        if (defined $w) {
            $wordref[$i&3][$w]++;
            $wordref[4+($i&1)][$w]++;
            $wordref[6][$w]++;
        }
        if ($xrefdwords && defined $d) {
            $dwordref[$i&3]{$d}++;
            $dwordref[4+($i&1)]{$d}++;
            $dwordref[6]{$d}++;
        }
    }

    dumprefs(1, "byte", \@byteref);
    dumprefs(2, "word", \@wordref);
    dumpdrefs(4, "dwrd", \@dwordref) if $xrefdwords;
}

sub dumprefs {
    my ($size, $name, $refs)= @_;
    $size *= 2;
    print "$name refs:\n";
    print "    ";
    my @width;
    for my $x (0..$#{$refs->[6]}) {
        my ($min, $max);
        for my $o (0..6) {
            next if !defined $refs->[$o][$x];
            $min = $refs->[$o][$x] if !defined $min || $min > $refs->[$o][$x];
            $max = $refs->[$o][$x] if !defined $max || $max < $refs->[$o][$x];
        }
        $width[$x]= (defined $max && $max>0) ? length("$max")  : 0;
        $width[$x]= $size if ($width[$x]>0 && $width[$x]<$size);

        printf(" %*s%0${size}x", $width[$x]-$size, "", $x) if $width[$x];
    }
    print "\n";

    my @desc=qw(.0 .1 .2 .3  .0 .1  -);
    for my $o (0..6) {
        printf("%-2s :", $desc[$o]);
        for my $x (0..$#{$refs->[6]}) {
            next if $width[$x]==0;
            printf(" %*d", $width[$x], $refs->[$o][$x] || 0);
        }
        printf("\n");
    }
}
sub dumpdrefs {
    my ($size, $name, $refs)= @_;
    $size *= 2;
    print "$name refs:\n";
    print "    ";
    my %width;
    for my $x (sort { $a <=> $b } keys %{$refs->[6]}) {
        my ($min, $max);
        for my $o (0..6) {
            next if !defined $refs->[$o]{$x};
            $min = $refs->[$o]{$x} if !defined $min || $min > $refs->[$o]{$x};
            $max = $refs->[$o]{$x} if !defined $max || $max < $refs->[$o]{$x};
        }
        $width{$x}= (defined $max && $max>0) ? length("$max")  : 0;
        $width{$x}= $size if ($width{$x}>0 && $width{$x}<$size);

        printf(" %*s%0${size}x", $width{$x}-$size, "", $x) if $width{$x};
    }
    print "\n";

    my @desc=qw(.0 .1 .2 .3  .0 .1  -);
    for my $o (0..6) {
        printf("%-2s :", $desc[$o]);
        for my $x (sort { $a <=> $b } keys %{$refs->[6]}) {
            next if $width{$x}==0;
            printf(" %*d", $width{$x}, $refs->[$o]{$x} || 0);
        }
        printf("\n");
    }
}