(j3.2006) Compilation cascades

[Robert Corbett]

Van Snyder wrote:

> We compare .mod files to avoid compilation cascades.
> 
> I noticed that if I add a PRINT statement to a module procedure, several
> processors produce a different .mod file.
> 
> This seems a bit bizarre.  Is it really necessary?
> 
> Some processors put a time stamp in the .mod file, but we've figured out
> how to get around that.

Some compilers put representations of the code for module procedures
in the .mod files they generate.  This allows inlining module
procedures, which are often short.  It is not necessary, but it can
be a big performance advantage.  Of course, if you use such a compiler,
the compilation cascades are pretty much necessary for correct
operation.  If a module procedure that has been inlined has been
modified, all files that include procedure references that
reference one of the module procedures must be recompiled.

Bob Corbett