GCC: program doesn't work with compilation option -O3

Question

I\'m writing a C++ program that doesn\'t work (I get a segmentation fault) when I compile it with optimizations (options -O1, -O2, -O3, etc.), but it works just fine when I

Answer 1

It's almost (almost) never the compiler.

First, make sure you're compiling warning-free, with -Wall.

If that didn't give you a "eureka" moment, attach a debugger to the least optimized version of your executable that crashes and see what it's doing and where it goes.

5 will get you 10 that you've fixed the problem by this point.