What is acceptable for -ffast-math?

[Kai Henningsen]

dewar@gnat.com  wrote on 01.08.01 in < 20010801171343.5E207F2B65@nile.gnat.com >:

> a/2.0/2.0 will never yield zero if a is non-zero
> a/4.0 may indeed yield zero if a is the smallest number

If a is the smallest positive number in some floating point type, then I  
would certainly expect both a/2.0 and a/4.0 do the same thing - either  
yield zero or signal underflow.

And I certainly do not see how a second /2.0 can possibly change that.

> Indeed if one saw a/2.0/2.0 that's pretty peculiar, and it would not be
> unreasonable to guess that the properly of not yielding zero was being
> exploited :-)

What buggy idea of floating point does this?!

MfG Kai