Re: GCC and Floating-Point

[Scott Robert Ladd <scott dot ladd at coyotegulch dot com>]

Allan Sandfeld Jensen wrote:
> Basically any compiler that cares about benchmarks have it enabled by default.
> 
> Many of them however have multiple levels of relaxed floating point. The 
> lowest levels will try to be as accurate as possible, while the higher will 
> loosen the accuracy and just try to be as fast as possible.

Perhaps we need something along these lines:

When -ansi or -pedantic is used, the compiler should disallow anything
"unsafe" that may break compliance, warning if someone uses a paradox
like "-ansi -funsafe-math-optimizations".

As has been pointed out elsewhere in this thread,
-funsafe-math-optimizations implies too many different things, and is
vaguely documented. I'd like to see varying levels of floating-point
optimization, including an option that uses an internal library
optimized for both speed and correctness, which are not mutually exclusive.

..Scott