Implementation of the reciprocal square root in MPFR.

Paul Zimmermann Implementation of the reciprocal square root in MPFR. 2008 Numerical Validation in Current Hardware Architectures http://drops.dagstuhl.de/opus/volltexte/2008/1435 conf/dagstuhl/2008P8021 db/conf/dagstuhl/P8021.html#Zimmermann08