#! perl -slw
use 5.010;
use strict;
use Inline C => Config => BUILD_NOISY => 1;
use Inline C => <<'END_C',  NAME => '_842899', CLEAN_AFTER_BUILD => 0;

void sumEm( SV *acc, SV *SoS, SV *in, int n ) {
    int *iAcc = (int*)SvPVX( acc );
    int *iIn  = (int*)SvPVX( in );
    int *iSoS = (int*)SvPVX( SoS );
    int i;

    for( i=0; i < n; ++i ) {
        iAcc[ i ] += iIn[ i ];
        iSoS[ i ] += iIn[ i ] * iIn[ i ];
    }
}

END_C

use Time::HiRes qw[ time ];

my $start = time;

my $acc = chr(0) x 4e6;
my $sos = $acc;

open I, '<:raw', 'cells' or die $!;
while( sysread( I, my $row, 4e6 ) ) {
    sumEm( $acc, $sos, $row, 1e6 );
}
close I;

printf "Took: %.6f seconds\n", time() - $start;

<STDIN>;

my @sums = unpack 'V*', $acc;
my @SoSs = unpack 'V*', $sos;

print "$sums[ $_ ] : $SoSs[ $_ ]" for 0 .. $#sums;

__END__
C:\test>842899.pl
Took: 39.318000 seconds