Re: Code optimization questions

cse264ce@cs.ucsd.edu (What Is) writes:
>[2] Is there any info on optimizers that take advantage of runtime
> assertions? This can help with anti dependencies, but it may have
> other advantages; for instance, if an integer is guaranteed to be
> within a certain range, then some operations on it may be cheaper,


A big assertion that optimizers take advantage of are the type
declarations. After all, choosing an adequate number representation was a
tough problem in the old days for Lisp compilers. They're always glad to
be able to use a short integer rather than some bignum representation.


There's also the various schemes people use to tell their compiler to
vectorize or parallelize a particular loop, regardless of how unsafe it
appears to the compiler.


On the other hand, I don't know of specific papers in the area.


BTW, the plural of "dependence" is "dependences".


>[3] If statement A has a def-use chain to statement B, does it follow
> that statement B has a use-def chain to statement A?


Yes.


Preston Briggs
--

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