To support different expectations, I suggest defining the following floating-point options for GCC. This is a conceptual overview; once there's a consensus the categories, I'll propose something more formal.
-ffp-correct This option focuses code generation on mathematical correctness, portability, and consistency. No 80-bit long doubles, no fsin/fcos, making certain that comparison operators work within reason. Note that this option can only go so far in ensuring portability, given that not every system supports IEEE 754 floats. -ffp-ieee754 To the best of our ability, assume and follow IEEE 754. Similar to the above, but assuming IEEE floats and doubles. Note that IEEE 754 has been undergoing some revision. -ffp-balanced (default) Balance correctness with speed, enabling performance optimizations that may reduce portability or consistency, but which do not alter the overall quality of results. Yeah, I know that's a bit fuzzy; formal definition of such an option depends on categorizing existing FP code generation (something I'm working on). -ffp-damn-the-torpedoes-full-speed-ahead Okay, maybe that should be something shorter, like -ffast-math or -ffp-fast. This option enables dangerous hardware intrinsics, and eschews all concerns about portability and consistency in the quest for speed. The behavior is likely to be the same as the current -ffast-math. Actually, I like *-ffp-damn-the-torpedoes-full-speed-ahead*. As Stroustrup once said, if you're going to do somethimg ugly, it should look ugly. ;) ..Scott
