MPFR 2.2.0 Release candidate

Jim White mathimagics at
Tue Sep 13 18:54:28 CEST 2005

I'm happy to advise successful build and tests of MPFR 2.2.0 release candidate as shared library (DLL) on Windows XP, with MSys.
1.  Win DLL building no longer requires manual gcc linkage step.  The configure script supports --disable-static --enable-shared and that works just like it does for GMP (hmmm, is this really new? Or has it been supported anyway - if so, forgive my being slow to discover it!)
2.  For version 2.1.2, I had manually patched the mpfr_const_log2 and mpfr_const_pi functions to cache the results, otherwise functions like mpfr_log became distinctively sluggish at higher precisions (when the proportional cost of calculating log2 and pi on the fly reached and passed a critical level).  This has been fixed in 2.2.0, and even when re-evaluation of log2 does have to be done, I see that this calculation has also been greatly improved in the new version (by a factor of 3 to 4 on my system at 50,000 digits precision).

3.  On my system, the new mpfr_sin() runs 1.75 to 2 times faster than before, and although  that's still slower than a GMP (mpf) version that I have written, the gap has been reduced - I was 2 to 3 times faster before at 10,000 to 100,000 digits, but now I'm only 1.2 to 1.6 times faster.
4.  mpfr_exp is more or less the same speed - I have an mpf version that runs 1.5 times faster, although this is in a narrower range (10,000 to 20,000) digits.  MPFR changes from a Taylor series to a Brent algorithm at this stage, and my mpf version (which always uses a Taylor-based method) runs at about the same speed at 50,000 digits, and starts to fall behind at 100,000 digits.
Jim White
14 Sep 2005

gmp-discuss-request at wrote:

Today's Topics:

3. MPFR 2.2.0 Release Candidate (Vincent Lefevre)

Date: Tue, 13 Sep 2005 10:13:27 +0200
From: Vincent Lefevre 
Subject: MPFR 2.2.0 Release Candidate
To: mpfr at
Cc: gmp-discuss at

The release of MPFR 2.2.0 is imminent. Please help to make this
release as good as possible by downloading and testing the
release candidate:

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