The V3R9 compiler, like the V3R7 and V3R8 compilers, must be installed in a PDSE. Also (and again like the V3R7 and V3R8 compilers), the LE runtime option XPLINK must be ON whenever you invoke the compiler. If you invoke the compiler under batch via IBMZPLI or under Unix System Servies via the pli command, the compiler itself will insure that it runs with XPLINK(ON). But if you are invoking the compiler in some other fashion, you must insure that XPLINK(ON) is in effect.
While Enterprise PL/I V3R9 contains some new options and some old options with new suboptions, the defaults for these new options and suboptions will make the compiler produce executable code that is compatible with the code produced by the Enterprise PL/I V3R8 compiler (or any of the releases since V3R3) with the following exceptions:
The compiler will no longer flag seemingly unused %INCLUDE statements (since this was confusing to too many customers, including the customer who requested it, and led to too many false alarms)
So, with the above caveats, if you use the default options, you can freely mix code compiled with V3R7 and V3R8 and V3R9. Hence, if you are moving from V3R8 (or V3R7 or V3R6 or V3R5 or V3R4 or V3R3) to V3R9, you do not have to recompile all your code.
Even if you are moving from V3R2 to V3R9, you do not need to recompile all your code as long as you heed the warnings in the previous section about the BACKREG, BIFPREC and EXTRN options.
V3R9 also introduced, as described in the Programming Guide, some new options and added suboptions to some old options, but the defaults for these will make the compiler produce the same code as under the V3R8 and earlier compilers. The new options are:
The options with new suboption are:
In brief, the changes to these options are:
The V3R9 compiler also dropped support for the COMPACT and TUNE options.