Yes, but funnily enough, doing an actual boolean test on an integer appears to sometimes be faster on my machine than doing the optimization. I'm not sure why, and the results vary. The output of my test script above with -10 and -2 as the first argument to timethis() cmpthese() respectively is: 

                Rate        var   constant noconstant
var        5014619/s         --       -10%       -40%
constant   5551194/s        11%         --       -33%
noconstant 8292829/s        65%        49%         --

[download]
                Rate   constant        var noconstant
constant   5505020/s         --       -17%       -23%
var        6604512/s        20%         --        -7%
noconstant 7120433/s        29%         8%         --

[download]
"What should it profit a man, if he should win a flame war, yet lose his cool?"

In reply to Re^3: use constant and Compiler Optimizations by Joost
in thread use constant and Compiler Optimizations by jbisbee

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.