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Re: GCC/G++ compiler: Error goes away when run through debugger

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On Sat, 26 Mar 2011 12:35:22 -0700 (PDT), "rhoads@cs.rutgers.edu"
<rhoads@cs.rutgers.edu> wrote:

>I'm using the gcc/g++ compiler under Cygwin (an UNIX emulator that
>runs on windows).
> :
>The -O3 optimizations are supposed to always produce the same
>results.  Running through the debugger is not supposed to change the
>results either.  Has anybody else encountered this behavior?

As Mark mentioned already, your problem is most likely uninitialized
variables.  But that said ...

GCC's -O3 optimization level is widely known to cause strange problems
... almost always because the program is violating assumptions made by
the more advanced optimizations.

The -O2 level typically is safe.  If you think you need the -O3
optimizations, you should individually enable them to see if any
breaks the program.  Specify -O3 only if you find they all work.

George

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Re: GCC/G++ compiler: Error goes away when run through debugger George Neuner <gneuner2@comcast.net> - 2011-03-29 12:18 -0400
  Re: GCC/G++ compiler: Error goes away when run through debugger ike@localhost.claranet.nl (Ike Naar) - 2011-03-29 21:42 +0000
    Re: GCC/G++ compiler: Error goes away when run through debugger George Neuner <gneuner2@comcast.net> - 2011-03-31 01:34 -0400
    Re: GCC/G++ compiler: Error goes away when run through debugger Shankar <shankarke@gmail.com> - 2011-04-01 15:31 -0700

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