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Date: Tue, 11 Apr 2006 19:12:50 -0400 (EDT)
From: Andy Reitz <reitz@eecs.cwru.edu>
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To: Jonathan Herriott <herriojr@gmail.com>
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Cc: freebsd-questions@freebsd.org, Nicolas Blais <nb_root@videotron.ca>
Subject: Re: pow function working unexpectedly
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On Tue, 11 Apr 2006, Jonathan Herriott wrote:

> Question then.  Why would it work when I don't use variables if I
> don't include the library?  This question is just out of curiosity.

That's a pretty good question. In the case where we have pow(x,y), I see
this:

areitz@bottom[~/src]$ gcc -c pow_test.c
areitz@bottom[~/src]$ nm pow_test.o
00000000 T main
         U pow
         U printf

In the case where it is pow(2,3), I see this:

areitz@bottom[~/src]$ gcc -c pow_test.c
areitz@bottom[~/src]$ nm pow_test.o
00000000 T main
         U printf

So, clearly, something is optimizing the pow() function away when the
arguments are hard-coded lvalues, instead of varibles.

Now, what that thing *is*, I don't know.

-Andy.