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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 /log.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 'log.c')
-rw-r--r-- | log.c | 59 |
1 files changed, 30 insertions, 29 deletions
@@ -51,50 +51,51 @@ mpfr_log (mpfr_ptr r, mpfr_srcptr a, mp_rnd_t rnd_mode) double ref; TMP_DECL(marker); - /* If a is NaN, the result is NaN */ - if (MPFR_IS_NAN(a)) + /* Special cases */ + if (MPFR_UNLIKELY( MPFR_IS_SINGULAR(a) )) { - MPFR_SET_NAN(r); - MPFR_RET_NAN; - } - - MPFR_CLEAR_NAN(r); - - /* check for infinity before zero */ - if (MPFR_IS_INF(a)) - { - if (MPFR_SIGN(a) < 0) /* log(-Inf) = NaN */ + /* If a is NaN, the result is NaN */ + if (MPFR_IS_NAN(a)) { MPFR_SET_NAN(r); - MPFR_RET_NAN; + MPFR_RET_NAN; } - else /* log(+Inf) = +Inf */ + MPFR_CLEAR_NAN(r); + /* check for infinity before zero */ + if (MPFR_IS_INF(a)) + { + if (MPFR_IS_NEG(a)) + /* log(-Inf) = NaN */ + { + MPFR_SET_NAN(r); + MPFR_RET_NAN; + } + else /* log(+Inf) = +Inf */ + { + MPFR_SET_INF(r); + MPFR_SET_POS(r); + MPFR_RET(0); + } + } + /* Now we can clear the flags without damage even if r == a */ + MPFR_CLEAR_INF(r); + if (MPFR_IS_ZERO(a)) { MPFR_SET_INF(r); - MPFR_SET_POS(r); - MPFR_RET(0); + MPFR_SET_NEG(r); + MPFR_RET(0); /* log(0) is an exact -infinity */ } } - - /* Now we can clear the flags without damage even if r == a */ - MPFR_CLEAR_INF(r); - - if (MPFR_IS_ZERO(a)) - { - MPFR_SET_INF(r); - MPFR_SET_NEG(r); - MPFR_RET(0); /* log(0) is an exact -infinity */ - } - + /* If a is negative, the result is NaN */ - if (MPFR_SIGN(a) < 0) + if (MPFR_UNLIKELY( MPFR_IS_NEG(a) )) { MPFR_SET_NAN(r); MPFR_RET_NAN; } /* If a is 1, the result is 0 */ - if (mpfr_cmp_ui (a, 1) == 0) + if (MPFR_UNLIKELY( mpfr_cmp_ui (a, 1) == 0) ) { MPFR_SET_ZERO(r); MPFR_SET_POS(r); |