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author | pelissip <pelissip@280ebfd0-de03-0410-8827-d642c229c3f4> | 2003-10-28 16:31:13 +0000 |
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committer | pelissip <pelissip@280ebfd0-de03-0410-8827-d642c229c3f4> | 2003-10-28 16:31:13 +0000 |
commit | 117edf14c822a22cdd9c25689aeadc904a1a30d1 (patch) | |
tree | e39bd61cefc24cc6cfbc5b2b956e4fb36015d111 /acos.c | |
parent | 734c0a144b04e2cae4e67b394010e3f6e3cadecc (diff) | |
download | mpfr-117edf14c822a22cdd9c25689aeadc904a1a30d1.tar.gz |
Use of MPFR_UNLIKELY and MPFR_IS_SINGULAR for fast detection of special values (Nan, Inf or Zero).
Start to encapsulate the sign to be independant of the reprensation (Must be 1 or -1).
git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@2525 280ebfd0-de03-0410-8827-d642c229c3f4
Diffstat (limited to 'acos.c')
-rw-r--r-- | acos.c | 31 |
1 files changed, 17 insertions, 14 deletions
@@ -40,11 +40,22 @@ mpfr_acos (mpfr_ptr acos, mpfr_srcptr x, mp_rnd_t rnd_mode) int compared; int inexact = 0; - /* Trivial cases */ - if (MPFR_IS_NAN(x) || MPFR_IS_INF(x)) + /* Special cases */ + if (MPFR_UNLIKELY( MPFR_IS_SINGULAR(x) )) { - MPFR_SET_NAN(acos); - MPFR_RET_NAN; + if (MPFR_IS_NAN(x) || MPFR_IS_INF(x)) + { + MPFR_SET_NAN(acos); + MPFR_RET_NAN; + } + else if (MPFR_IS_ZERO(x)) + { + /* acos(0)=Pi/2 */ + mpfr_const_pi (acos, rnd_mode); + MPFR_SET_EXP (acos, MPFR_GET_EXP (acos) - 1); + return 1; /* inexact */ + } + MPFR_ASSERTN(1); } /* Set x_p=|x| */ @@ -64,7 +75,7 @@ mpfr_acos (mpfr_ptr acos, mpfr_srcptr x, mp_rnd_t rnd_mode) if (compared == 0) { mpfr_clear (xp); - if (signe > 0) /* acos(+1) = 0 */ + if (MPFR_IS_POS_SIGN(signe)) /* acos(+1) = 0 */ return mpfr_set_ui (acos, 0, rnd_mode); else /* acos(-1) = Pi */ { @@ -73,18 +84,10 @@ mpfr_acos (mpfr_ptr acos, mpfr_srcptr x, mp_rnd_t rnd_mode) } } - if (MPFR_IS_ZERO(x)) /* acos(0)=Pi/2 */ - { - mpfr_clear (xp); - mpfr_const_pi (acos, rnd_mode); - MPFR_SET_EXP (acos, MPFR_GET_EXP (acos) - 1); - return 1; /* inexact */ - } - prec_acos = MPFR_PREC(acos); mpfr_ui_sub (xp, 1, xp, GMP_RNDD); - if (signe > 0) + if (MPFR_IS_POS_SIGN(signe)) supplement = 2 - 2 * MPFR_GET_EXP (xp); else supplement = 2 - MPFR_GET_EXP(xp); |