libfast.a is a 32-bit, SPARC-specific version of the standard C library which provides optimized memory allocation for single-threaded, single-executible applications. Because it is an optional library, it can use algorithms and data representations that may not be appropriate for the standard C library, even though they improve the performance of most applications.
Use profiling to determine whether the routines in the following checklist are important to the performance of your application, then use this checklist to decide whether libfast.a benefits the performance:
Do use libfast.a if the performance of memory allocation is important, and the size of the most commonly allocated blocks is close to a power of two. The important routines are: malloc(), free(), realloc().
Do use libfast.a if the performance of block-move or block-fill routines is important. The important routines are: bcopy(), bzero(), memcpy(), memmove(), and memset().
Do not use libfast.a if the application is multithreaded.
When linking the application, add the option -lfast to the cc command used at link time. The cc command links the routines in libfast.a ahead of their counterparts in the standard C library.