Disclaimer: I know she's using Red Hat Linux, but I can't find out anything about her compiler at the moment as the cluster she runs all this on seems to have died. Hopefully I'll be able to provide this soon though.
--- My girlfriend, who is a mathematician and competent C++ programmer, has an app that does some tricky stuff with bits of DNA. Currently, it has to run for at least 18 hours before she can get any results back from it. Now, although she's a decent enough programmer, she doesn't have much of a clue when it comes to optimisation, e.g., she's never profiled anything in her life, has never heard of compiler optimisations or linking with libraries that are perhaps more tailored to her needs, ... I suggested that she A) profile her code, B) find a version of some of the STL classes that were perhaps rather more efficient than the ones she was using C) consider re-compiling some of the library code she's using with some decent optimisations. Now, I'm not a g++ user, so I have no clue as to how I can help her find/test some of this stuff - thus this post. So, some questions: 1. Is there a recommended [tried/tested] version of the STL Vector class that's likely to be faster than the one she's using [I've no idea as to where her existing one came from, but, knowing her department, it would have simply come bundled with something else - g++ perhaps]? 2. How difficult would it be to recompile parts of the library code she uses [if she can find the sources], e.g., is the STL Vector class easy enough to recompile into a .o etc? 3. Are there debug versions of the standard and STL libraries? And, how can one tell if a library is a debug version or not [just want to check she's not linking with these right now!] **and** is there an easy way to find what libraries she's linking with - perhaps through asking the linker [rather than following paths]? 4. What are a decent set of basic compiler optimisation switches to use - for speed [think she's using -O3 at the moment]? 5. How can I help her profile her code [and make sense of the results] Very many thanks! _______________________________________________ help-gplusplus mailing list help-gplusplus@gnu.org http://lists.gnu.org/mailman/listinfo/help-gplusplus
