diff options
author | zimmerma <zimmerma@280ebfd0-de03-0410-8827-d642c229c3f4> | 2004-01-22 22:30:52 +0000 |
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committer | zimmerma <zimmerma@280ebfd0-de03-0410-8827-d642c229c3f4> | 2004-01-22 22:30:52 +0000 |
commit | 031deac645662aea8a72a5ed0c0bf148e609e681 (patch) | |
tree | 07c68b885a0c39a228ca4b0f7f901a9117f85a9f /atanh.c | |
parent | 039c1c0135bac8353d17020543fe8b27f3b1937e (diff) | |
download | mpfr-031deac645662aea8a72a5ed0c0bf148e609e681.tar.gz |
added several hard-coded tests (and fixed bugs found)
git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@2644 280ebfd0-de03-0410-8827-d642c229c3f4
Diffstat (limited to 'atanh.c')
-rw-r--r-- | atanh.c | 39 |
1 files changed, 25 insertions, 14 deletions
@@ -1,6 +1,6 @@ /* mpfr_atanh -- Inverse Hyperbolic Tangente of Unsigned Integer Number -Copyright 2001, 2002, 2003 Free Software Foundation. +Copyright 2001, 2002, 2003, 2004 Free Software Foundation. This file is part of the MPFR Library. @@ -32,24 +32,20 @@ MA 02111-1307, USA. */ int mpfr_atanh (mpfr_ptr y, mpfr_srcptr xt , mp_rnd_t rnd_mode) { - int inexact =0; + int inexact = 0; mpfr_t x; - mp_prec_t Nx=MPFR_PREC(xt); /* Precision of input variable */ + mp_prec_t Nx = MPFR_PREC(xt); /* Precision of input variable */ /* Special cases */ if (MPFR_UNLIKELY( MPFR_IS_SINGULAR(xt) )) { - if (MPFR_IS_NAN(xt)) + /* atanh(NaN) = NaN, and atanh(+/-Inf) = NaN since tanh gives a result + between -1 and 1 */ + if (MPFR_IS_NAN(xt) || MPFR_IS_INF(xt)) { MPFR_SET_NAN(y); MPFR_RET_NAN; } - else if (MPFR_IS_INF(xt)) - { - MPFR_SET_INF(y); - MPFR_SET_SAME_SIGN(y, xt); - MPFR_RET(0); - } else if (MPFR_IS_ZERO(xt)) { MPFR_SET_ZERO(y); /* atanh(0) = 0 */ @@ -61,9 +57,25 @@ mpfr_atanh (mpfr_ptr y, mpfr_srcptr xt , mp_rnd_t rnd_mode) } /* Useless due to final mpfr_set MPFR_CLEAR_FLAGS(y);*/ - - mpfr_init2(x,Nx); - mpfr_abs(x, xt, GMP_RNDN); + + /* atanh(x) = NaN as soon as |x| > 1, and arctanh(+/-1) = +/-Inf */ + if (MPFR_EXP(xt) > 0) + { + if (MPFR_EXP(xt) == 1) + { + if (mpfr_cmp_ui (xt, 1) || mpfr_cmp_si (xt, -1)) + { + MPFR_SET_INF(y); + MPFR_SET_SAME_SIGN(y, xt); + MPFR_RET(0); + } + } + MPFR_SET_NAN(y); + MPFR_RET_NAN; + } + + mpfr_init2 (x, Nx); + mpfr_abs (x, xt, GMP_RNDN); /* General case */ { @@ -108,7 +120,6 @@ mpfr_atanh (mpfr_ptr y, mpfr_srcptr xt , mp_rnd_t rnd_mode) /* actualisation of the precision */ Nt += 10; - } while ((err < 0) || (!mpfr_can_round (t, err, GMP_RNDN, GMP_RNDZ, Ny + (rnd_mode == GMP_RNDN)) |