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 V3R5 (or V3R3 or V3R4) compiler - with one exception:
So, if you use the default options, you can freely mix code compiled with V3R5 and V3R8. Hence, if you are moving from V3R5 (or 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.
V3R6 also made these changes to the compiler options:
Note that under V3R6, the default for CEESTART option was CEESTART(LAST). This will make the compiler place the CEESTART CSECT at the end of its generated object deck. While this is required if you are using linker CHANGE cards, it is different than what was done under earlier releases of the compiler. Moreover, if you do not use an ENTRY CEESTART linker card when binding your objects, this will cause your code to behave incorrectly. Most customers will probably prefer to use the CEESTART(FIRST) option.