"willus.com" <willus....@willus.com> writes: >> For the math functions, this is normally more a libc feature, so you >> might get very different results on different OS. Then again, by using >> -ffast-math, you allow the math functions to return any random value, >> so I can think of ways to make it even faster ;-) > > I use -ffast-math all the time and have always gotten virtually > identical results to when I turn it off. The speed difference is > important for me.
Also, of course, "-ffast-math" is really shorthand for a bunch of more detailed options; which are OK and which are not is often very application-dependent. One can easily fine-tune the result by either using the more detailed options instead of -ffast-math, or perhaps by specifying -ffast-math and then turning _off_ (with -fno-xxx) anything that's too risky.... -Miles -- `There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy.'