Re: Optimizing Across && And ||

>jqb@netcom.com (Jim Balter) writes:
> What these people may be missing is that there is another side to dead code
> detection, namely *notification*. It is true that properly written programs
> shouldn't contain dead code. Therefore, presence of dead code indicates
> a possible problem.


While this is often true for a program which is written to solve one problem
on one machine, it is very often NOT true for software which is:
  1) written to work efficiently in a portable environment.
    ---code tests invariants to determine which of two tuned loops to use.
  2) re-compiled with differing size parameters fixed.
    ---code tests whether certain tables "fit" to determine data structures.
  3) properly written ( :-> )
    ---Assertions are placed in the code to verify invariants.
Any programming system which rewards the removal of invariant
checking by the programmer is, IMHO, wrong-headed. Perhaps you
need a way to allow the programmer to claim some code may be
dead. I personally would like my compiler to remove code for
any of my assertions that it could prove true.


-Scott David Daniels
  daniels@cse.ogi.edu
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