Re: Any thoughts

[Barbara Morris <bmorris@xxxxxxxxxx>]

Tony Carolla wrote:
> 
> The compiler was improved.  I would hope that, over time, if an
> updated compiler is provided by IBM, that it would generate, among
> other things, faster code.  I would bet that Barbara could give you
> more details as to why, but consider the other advantages, besides
> speed of execution.  Re-usable modules, static or dynamic binding,
> multiple executable modules that use different source types (SQL, CL,
> RPGLE) in one program, etc. etc.
> 

There are a few areas where the ILE RPG compiler runs faster because of
the way the compiler and runtime are coded.  For example, the handling
of eof and record-not-found is much faster for ILE RPG.  Also, program
initialization is much faster when you have no PSDS or a small PSDS
(this is most dramatic when the called program returns immediately).

There may be some difference due to the fact that the ILE RPG runtime is
statically bound and the OPM runtime is not, but this may not be as big
a difference as you'd expect, because the OPM RPG runtime is used much
less than the ILE RPG runtime.  Many OPM RPG programs only call the
initialization runtime program; all the code is generated directly into
the program rather than calling out to the runtime; system programs for
file handling are called directly from the generated code.

I think most of the difference is due to the optimizating translator
used by the ILE compilers, which takes the code generated by the
compiler and generates machine code.