The Makefile.Irix and Makefile.INC contain the description to build the library spr_sg6.a. When SPRLIB is compiled using make shared, a shared library libspr_sg6.so.1.0 is made from the object files in the library. The library functions require the global defines SPRLIB and SGI to be set when compiling the source code. See the CFLAGS in Makefile.Irix. Note: Makefile.Irix.DBG creates a library compiled with -g which can be used for debugging with a debugger (gdb/xxgdb/ddd). The debug version of the library is called sprg_sg6.a.