David Jones wrote: > Both the C++ executable and python module were linked from the same > object files, and linked with the same options. The only difference is > that the Python module is linked with -shared, and the C++ code is not. [...] > Some potential causes of my problems: > > - linking to a shared library instead building a static exe.
That is unlikely the problem - the shared library should long be loaded when you call the function. > - intel libraries are not being used when I think they are Very much possible. I would do an strace on each binary (python and your stand-alone application) to see what libraries are picked up. > - libpython.so was built with gcc, so I am getting some link issues Unlikely. > - can linking to python affect my memory allocation and deallocation in > c++?? It can - Python grabs a 128k at startup, and then another one if the first one is exhausted. But that should not cause a performance difference. Other possible explanations: - The intel compiler somehow arranges to use multiple processors in the code (e.g. through OpenMP); for some reason, your multiple processor are not used when this is run in the Python interpreter (and no, the GIL would not be an immediate explanation) - The Python interpreter (unknowingly) switches the processor to a different floating-point operation mode, one which is less efficient (but, say, more correct). Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
