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

1 files changed, 15 insertions, 11 deletions

diff --git a/tan.c b/tan.c
index c93275a5b..c62a2193d 100644
--- a/tan.c
+++ b/tan.c
@@ -31,18 +31,22 @@ mpfr_tan (mpfr_ptr y, mpfr_srcptr x, mp_rnd_t rnd_mode)
   int precy, m, ok, inexact;
   mpfr_t s, c;
 
-  if (MPFR_IS_NAN(x) || MPFR_IS_INF(x))
+  if (MPFR_UNLIKELY(MPFR_IS_SINGULAR(x)))
     {
-      MPFR_SET_NAN(y);
-      MPFR_RET_NAN;
-    }
-
-  if (MPFR_IS_ZERO(x))
-    {
-      MPFR_CLEAR_FLAGS(y);
-      MPFR_SET_ZERO(y);
-      MPFR_SET_SAME_SIGN(y, x);
-      MPFR_RET(0);
+      if (MPFR_IS_NAN(x) || MPFR_IS_INF(x))
+	{
+	  MPFR_SET_NAN(y);
+	  MPFR_RET_NAN;
+	}
+      else if (MPFR_IS_ZERO(x))
+	{
+	  MPFR_CLEAR_FLAGS(y);
+	  MPFR_SET_ZERO(y);
+	  MPFR_SET_SAME_SIGN(y, x);
+	  MPFR_RET(0);
+	}
+      /* Should never reach this point */
+      MPFR_ASSERTN(1);
     }
 
   precy = MPFR_PREC(y);