The Libraries

Sun MPI comprises eight MPI libraries: four 32-bit versions and four 64-bit versions:

• 32- and 64-bit libraries - If you want to take advantage of the 64-bit capabilities of Sun MPI 4.0, you must explicitly link to the 64-bit libraries. The 32-bit libraries are the default in each category.

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  Note -

  The 64-bit libraries are installed only when the installation system is running Solaris 7.

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• Thread-safe and non-thread-safe libraries - For multithreaded programs, the user must link with the thread-safe library in the appropriate category unless the program has only one thread calling MPI. For programs that are not multithreaded, the user can link against either the thread-safe or the default (non-thread-safe) library. However, non-multithreaded programs will have better performance using the default library, as it does not incur the extra overhead of providing thread-safety. Therefore, you should use the default libraries whenever possible for maximum performance.

• Standard and trace libraries - The trace libraries are used to take advantage of Prism's MPI performance analysis features and to provide enhanced error reporting. These libraries are intended for development purposes only, as the overhead involved in their aggressive parameter-checking and probes degrades performance compared with the standard libraries.

The 32-bit libraries are the default, as are the standard (nontrace) libraries within the 32- or 64-bit categories. Within any given category (32- or 64-bit, standard or trace library), the non-thread-safe library is the default. For full information about linking to libraries, see "Compiling and Linking".