While Enterprise PL/I V3R8 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 V3R4 (or V3R3) compiler - with one exception:
So, if you use the default options, you can freely mix code compiled with V3R4 and V3R8. Hence, if you are moving from V3R4 (or V3R3) to V3R8, you do not have to recompile all your code.
Even if you are moving from V3R2 to V3R8, 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.
V3R5 also changed how the compiler behaved when you specify the PP option more than once. Previous to V3R5, the last specification would replace any previous specification, but with V3R5, the option is, additive (as are the RULES and other options). So, if you specify PP(CICS) PP(SQL), it is the same as if you specify PP(CICS SQL).
V3R5 also stopped support for these compiler options: