What is acceptable for -ffast-math? (Was: associative law in combine)

[Gabriel Dos Reis]

Theodore Papadopoulo <Theodore.Papadopoulo@sophia.inria.fr> writes:

| gdr@codesourcery.com said:
| > That doesn't mean I don't want optimization.  I do love optimization.
| > By optimization, I really mean optimization. 
| 
| No by optimisation, you mean mathematically provable safe optimisation and 

No, I do mean a transformation which does not dramatically transmute 
the computations.  

Where did you get the idea that I meant "mathematically provable safe
optimisation"?

We're talking here of transformations which we do know able to
drastically change the results.
Going into abstract considerations like NP-completness is beside the
point. 

-- Gaby