[Bug tree-optimization/42108] [4.4/4.5 Regression] Vectorizer cannot deal with PAREN_EXPR gracefully, 50% performance regression

[sfilippone at uniroma2 dot it]

------- Comment #8 from sfilippone at uniroma2 dot it  2009-11-20 08:32 -------
(In reply to comment #6)
> Richard Guenther wrote:
> 
> > Well, within eval there's nothing really obvious to me.  The
> > innermost loop is exactly the same:
> 
> But it is a very inefficient way of vectorizing, because the inner loop's body
> is either executed twice or three times per outer loop (depending on the value
> of i).
> 
While I agree that I would code in a different way, still there is the change
in compiler's behaviour. Although comment 7 indicates it's probably only at
64bits


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42108