On Sun, 5 Aug 2018, Bernd Edlinger wrote:
merging log a + log b => log a*b and
Maybe a*b could overflow, while adding the logarithms would not?
Well, that's a discussion that happens every time a new transformation is
added to -funsafe-math-optimizations (I assume this one is under that
umbrella?). We already may get extra overflow with -fassociative-math for
instance. Sure, the overflow (or underflow!) is more likely for log than
for addition, but this still seems like the kind of transformation that
-ffast-math should enable, in my opinion. Now we can see if I am in the
minority...
--
Marc Glisse
