OpenVMS I64 only.
Associates a named or anonymous linkage with a routine name. When
the compiler sees a CALLS, CALLG, JSB, BSBB, or BSBW instruction
with the routine name as the target, it will use the associated
linkage to decide which registers need to be saved and restored
around the call.
Format
.CALL_LINKAGE routine_name [,linkage_name] [,input] [,output]
[,scratch] [,preserve]
Parameters