-funsafe-loop-optimizations

Daniel Berlin dberlin@dberlin.org
Fri Dec 31 21:57:00 GMT 2004



On Fri, 31 Dec 2004, Zdenek Dvorak wrote:

> Hello,
>
> several times some people sounded opinion that in addition to improving
> analyses in loop optimizer, we might also add a flag that would enable
> the compiler to assume that the compiled code does not contain loops
> behaving in "weird" way (loops whose control induction variables
> overflows, infinite loops with nontrivial exit conditions).

Almost all compilers i know of turn this on by default at -O2 or higher.
So if we do tihs, i believe we should do that same.
(xlc has nostrict_induction to turn this off, for example, and issues one 
warning per compilation if it discovers a loop where it could matter. We 
could simply do the same.)



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