I ran your code as written and it didn't work. I used the sample input (taken from the sudoku widget in my iGoogle): 
-,-,4,-,-,2,-,-,3
-,2,2,-,9,-,7,1,5
7,-,-,3,1,-,4,-,-
-,1,-,-,-,-,2,-,9
-,4,-,2,7,-,-,-,6
2,8,-,5,-,-,-,-,-
5,-,-,-,-,3,6,-,4
-,3,1,-,-,8,-,-,2
4,6,-,-,5,-,-,3,1

[download]

In reading the code, your recursive function doesn't actually solve anything, as far as I can tell. Please verify that you actually posted the right code.

As for what's going on, there are a number of places I can see as possibly improving the code and the performance, potentially by several orders of magnitude. I just need to see working code first in order to apply the right fixes.

My criteria for good software:
  1. Does it work?
  2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?

In reply to Re: Subroutine overhead in Perl by dragonchild
in thread Subroutine overhead in Perl by enemyofthestate

Title:
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, details, 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, summary, 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.