Paolo Bonzini wrote:
Sylvain Pion wrote:
Andrew Thomas Pinski wrote:
The fact is that Roger's patch introduced a regression (this word
should be clear enough here), in that some users now have their old
code broken, and they are forced to add the -frounding-math option
(after having lost some time finding about this non trivial issue).
This is a long term hindrance.
Actually before roger's patch the default is the same. Just there was
no way to turn it off.
Actually, there are 2 things controlled by -frounding-math :
1) constant propagation of FP operations
2) generic transformations like (-a)*b <-> -(a*b)
I think 2) is taken care of by -fassociative-math, or it should at least.
I don't think it is (I haven't checked), and I don't see why it should.
This transformation has nothing to do with associativity : unless I'm
mistaken, it is always valid when rounding is to the nearest or towards
zero.
--
Sylvain Pion
INRIA Sophia-Antipolis
Geometrica Project-Team
CGAL, http://cgal.org/
