Looks to me, "C from C" on Windows got optimized away

I don't think so. (Could be wrong but.)
A clearer ilustration is (hopefully) this script: 
use Time::HiRes qw(time);

use Inline C => Config =>
  #OPTIMIZE => '-O0',
  FORCE_BUILD => 1;

use Inline C => <<'EOC';

void foo() {}

void foo_bar(int x) {
  int i;
  for(i = 0; i < x; i++){
    foo();
  }
}


EOC

$iterations = 10000000;
$t = time;
foo() for 1 .. $iterations;
print "# ", time - $t, "\n";

$t = time;
foo_bar($iterations);
print "# ", time - $t, "\n";

[download]
As it stands, with optimization enabled, it outputs (on Windows): 
# 1.02960205078125
# 1.00135803222656e-005

[download]
Now that second value does look like something was optimized away. I'm thinking the loop is simply doing nothing at each iteration.
When we switch optimization off by including the "OPTIMIZE => '-O0'" line, the output changes to (on Windows): 
# 1.10760188102722
# 0.0196361541748047

[download]
The "C from C" code now takes 500 times longer to execute - because, I think, this time foo() is actually being called at each iteration. But it's still 50 times quicker than calling "C from Perl".

I've no useful ideas regarding things that can be done to enable Windows to access C subs as quickly as it can access Perl subs - and that's the main reason that I'm avoiding that aspect.

Cheers,
Rob

In reply to Re^3: Inline::C on Windows: how to improve performance of compiled code? by syphilis
in thread Inline::C on Windows: how to improve performance of compiled code? by vr

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.