[Bug tree-optimization/33928] [4.3/4.4 Regression] 30% performance slowdown in floating-point code caused by r118475

[bonzini at gnu dot org]

------- Comment #48 from bonzini at gnu dot org  2009-02-13 20:09 -------
Subject: Re:  [4.3/4.4 Regression] 30% 
        performance slowdown in floating-point code caused by r118475

> Yes.  I don't see why the optimizations in CSE, which were relatively
> cheap and which were effective for this case, needed to be disabled when
> FWPROP was added without, evidently, understanding why FWPROP does not
> do what CSE was already doing.

Just to mention it, fwprop saved 3% of compile time.  That's not
"cheap".  It was also tested with SPEC and Nullstone on several
architectures.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33928