Must useless expressions be evaluated?

[Sam Kendall]

Steven M. Haflich has some good points about possibly evaluating
expressions that seem to have no side effects, but that actually
do because of reference to special locations.  One should be
able to tell the compiler when such things may occur in a piece
of code, like you can in BLISS only less elaborate,* but anyway I
was jumping the gun when I rudely suggested this topic be dropped.
It is not so easily dismissed, and I apologize.

	Sam Kendall		  {allegra,ihnp4}!wjh12!kendall
	Delft Consulting Corp.	    decvax!genrad!wjh12!kendall

*There was extensive discussion of these points a while back.