RFC: Reorganization of gfortran.texi

[Tim Prince]

Brooks Moses wrote:

> 
> What, precisely, should the warning say?  Something along the lines of 
> this?:  "Enables code optimizations which occasionally produce incorrect 
> answers to mathematical operations, but will produce them faster than 
> reliably correct answers can be generated.  This option should be 
> avoided unless the compiled program can be thoroughly tested for 
> correctness.  Operations on complex numbers with -ffast-math are 
> particularly likely to obtain incorrect results."
> 
The comment about complex should be more precise, such as "complex 
number expressions under -ffast-math are not protected against 
intermediate overflow, thus reducing the range of values for which 
correct results may be expected."