[Bug middle-end/31723] Use reciprocal and reciprocal square root with -ffast-math

[jb at gcc dot gnu dot org]

------- Comment #4 from jb at gcc dot gnu dot org  2007-04-27 11:29 -------
(In reply to comment #3)
> 1. Convert to single precision
> 2. Calculate rcp(s|p)s or rsqrt(p|s)s
> 3. Refine with newton iteration
> 
> vs. just using div(p|s)d or sqrt(p|s)d?

This should be

1. Convert to single precision
2. Calculate rcp(s|p)s or rsqrt(p|s)s
3. Convert back to double precision
4. Refine with newton iteration


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31723