Compiler-generated default prolog and epilog code

The default prolog and epilog code generated for the "main" function is very much the same as the code produced by the sample prolog and epilog macros in Figure 1 and Figure 1. That is, a STORAGE macro is used to obtain and release a dynamic storage area of 1 MB. For functions other than "main", the prolog code simply picks up its DSA pointer (the NAB pointer) from the "Address of next save area" field in the calling function’s save area.