Effects of Ada Coding Style on Compiler Optimizations

[neptune@Ada1.crd.ge.com (Keith Gehring)]

I am looking for a list of Ada features that, by their nature, thwart an
Ada compiler from optimizing a program (e.g., use of separates kills 
common subexpression elimination in the calling routine.) or are expensive
to use in terms of code size and speed (e.g., use of unconstrained array
types as subprogram parameters forces runtime determination of array size
vs. compile time determination).  I know there are more than these.

I would also appreciate any explanation as to why a particular feature
cannot be fully optimized (it may not be obvious to me).

I'll take any references to books, technical articles, personal 
experience/knowledge, etc.  

Thanks,

Keith L. Gehring
513-583-5373
neptune@Ada1.crd.ge.com