Description

   The .JSB32_ENTRY directive is an alternative way of declaring a
   JSB entry point. It is designed to streamline the declaration of
   VAX MACRO routines that operate within a well-defined, bounded
   application environment, such as that of a single application
   or a self-contained subsystem. For any routine declared with the
   .JSB32_ENTRY directive, the compiler does not automatically save
   or restore any VAX registers (R2 through R12), therefore leaving
   the current 32-bit operation untouched. When you use the .JSB32_
   ENTRY directive to declare a JSB entry point, you are responsible
   for declaring and saving registers which must be preserved.

   If the externally visible entry points of a subsystem can be
   called from the 64-bit environment, those entry points should
   not be declared with .JSB32_ENTRY. Instead, .JSB_ENTRY (or .CALL_
   ENTRY) should be used so that the full 64-bit register values are
   saved, if necessary.