Optimized Binary64 and Binary128 Arithmetic with GNU MPFR
Vincent Lefèvre, Paul A. Zimmermann · 2017
We describe algorithms used to optimize the GNU MPFR library when the operands fit into one or two words. On modern processors, this gives a speedup for a correctly rounded addition, subtraction, multiplication, division or square root in the standard binary64 format (resp. binary128) between 1.8 and 3.5 (resp. between 1.6 and 3.2). We also introduce a new faithful rounding mode, which enables even faster computations. Those optimizations will be available in version 4 of MPFR.