Beefy Boxes and Bandwidth Generously Provided by pair Networks
Do you know where your variables are?

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
I'd use left and right shift. I don't know how this would benchmark (and I don't have the time or energy to try ;) against your version, but this looks cleaner, at least to me.

sub pack64bit { my $i = new Math::BigInt shift(); my $j = new Math::BigInt $i->brsft(32); my $k = $i - $j->blsft(32); return pack('NN', $j, $k); }

Mine (as well as yours) will break if something unexpected is passed.

Update:Anonymous Monk, otherwise known as frankied noticed that this breaks for negative numbers.

Something bothered me anyway about using Math::BigInt to manipulate bits, so I did a rewrite using Bit::Vector:

sub pack_bv{ use Bit::Vector; my $vec = Bit::Vector->new_Dec(64, shift); return pack 'NN', $vec->Chunk_Read(32, 32), $vec->Chunk_Read(32, 0); }

This one looks even cleaner - and better yet, it works!

In reply to Re: pack 64 bit int ? by jsprat
in thread pack 64 bit int ? by frankied

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others imbibing at the Monastery: (9)
    As of 2021-04-12 12:34 GMT
    Find Nodes?
      Voting Booth?

      No recent polls found