Activate -mrecip with -ffast-math?

[Uros Bizjak]

Hello!

> I was wondering if there are objects to automatically activating Uros' 
> new -mrecip flag when -ffast-math is specified. It looks like a good 
> match since -mrecip is exactly about fast non-precise mathematics.

There is a discussion in gcc-patches@ mailing list about this topic, in 
"Re: [PATCH, middle-end, i386]: reciprocal rsqrt pass + full recip x86 
backend support" thread [1]. The main problem is, that one of the 
polyhedron tests segfaults with this patch (not the problem of the recip 
patch, but usage of questionable FP equivalence tests and FP indexes in 
the array).

Uros.

[1]: http://gcc.gnu.org/ml/gcc-patches/2007-06/msg01146.html