On Wed, 09 Jul 2008 03:31:35 +0100, James Gregory wrote: > 1. Compile with MSVC 7.1, no optimization: my program doesn't freeze 2. > Compile with MSVC 7.1, with optimization: my program doesn't freeze 3. > Compile with gcc 4.2.3 (Ubuntu 64 bit), no optimization: my program > doesn't freeze > 4. Compile with gcc 4.2.3 (Ubuntu 64 bit), with optimization: my program > freezes in a particular function 5. Compile with gcc 4.2.3 (Ubuntu 64 > bit), with optimization, and include <iostream> at the top of the file > where the function which freezes is defined: my program doesn't freeze You give *way* too little information to even begin to guess what the problem might be... but this smells like a classic case of Undefined Behaviour - sometimes it appears to work, sometimes it doesn't. I.e. you have a bug in your program. > Debugging this is difficult. It frequently is ;-) but what other choice do you have? There are tools to help (debuggers such as gdb, memory leak checkers such as valgrind, ...) First I would try stripping your program down to a minimal core that exhibits the buggy behaviour. Often in doing so you will isolate and identify the bug. If not seek help here or in a C (or C++, you don't say which language your program is in) forum. You can post minimal code demonstrating the problem. -- Lionel B
