diff options
| author | pelissip <pelissip@280ebfd0-de03-0410-8827-d642c229c3f4> | 2005-03-24 10:47:41 +0000 |
|---|---|---|
| committer | pelissip <pelissip@280ebfd0-de03-0410-8827-d642c229c3f4> | 2005-03-24 10:47:41 +0000 |
| commit | e62332ff03a6fe7486a6b490ba32dc3604ba8b74 (patch) | |
| tree | 41d4479fcde742cb5ee856b819a931d0a05d39df /mul.c | |
| parent | 36a699bc39ff00e5bf9115d9fe429655e08acb97 (diff) | |
| download | mpfr-e62332ff03a6fe7486a6b490ba32dc3604ba8b74.tar.gz | |
Fix wrong extimated precision.
It is log2(n+2) ulps so that log2(log2(n+2)) bits!
git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@3405 280ebfd0-de03-0410-8827-d642c229c3f4
Diffstat (limited to 'mul.c')
| -rw-r--r-- | mul.c | 6 |
1 files changed, 4 insertions, 2 deletions
@@ -359,7 +359,8 @@ mpfr_mul (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mp_rnd_t rnd_mode) n = MPFR_LIMB_SIZE (a) + 1; n = MIN (n, cn); MPFR_ASSERTD (n >= 1 && 2*n <= k && n <= cn && n <= bn); - p = n*BITS_PER_MP_LIMB - MPFR_INT_CEIL_LOG2 (n + 2) ; + p = n*BITS_PER_MP_LIMB + - MPFR_INT_CEIL_LOG2 (MPFR_INT_CEIL_LOG2 (n + 2)) -1; bp = MPFR_MANT (b) + bn - n; cp = MPFR_MANT (c) + cn - n; /* Check if MulHigh can produce a roundable result. @@ -393,7 +394,8 @@ mpfr_mul (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mp_rnd_t rnd_mode) } /* We will compute with one extra limb */ n++; - p = n*BITS_PER_MP_LIMB - MPFR_INT_CEIL_LOG2 (n + 2); + p = n*BITS_PER_MP_LIMB + - MPFR_INT_CEIL_LOG2 (MPFR_INT_CEIL_LOG2 (n + 2)) - 1; MPFR_ASSERTD (MPFR_PREC (a) <= p - 5); if (MPFR_LIKELY (k < 2*n)) { |