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, 20 insertions, 21 deletions

diff --git a/exp.c b/exp.c
index 9439b8e5e..0a9ba2675 100644
--- a/exp.c
+++ b/exp.c
@@ -38,34 +38,33 @@ mpfr_exp (mpfr_ptr y, mpfr_srcptr x, mp_rnd_t rnd_mode)
   int expx, precy;
   double d;
 
-  if (MPFR_IS_NAN(x))
+  if (MPFR_UNLIKELY( MPFR_IS_SINGULAR(x) ))
     {
-      MPFR_SET_NAN(y);
-      MPFR_RET_NAN;
-    }
-
-  MPFR_CLEAR_NAN(y);
-
-  if (MPFR_IS_INF(x))
-    {
-      if (MPFR_SIGN(x) > 0)
+      if (MPFR_IS_NAN(x))
 	{
-	  MPFR_SET_INF(y);
+	  MPFR_SET_NAN(y);
+	  MPFR_RET_NAN;
 	}
-      else
+      MPFR_CLEAR_NAN(y);
+      if (MPFR_IS_INF(x))
 	{
-	  MPFR_CLEAR_INF(y);
-	  MPFR_SET_ZERO(y);
+	  if (MPFR_IS_POS(x))
+	    {
+	      MPFR_SET_INF(y);
+	    }
+	  else
+	    {
+	      MPFR_CLEAR_INF(y);
+	      MPFR_SET_ZERO(y);
+	    }
+	  MPFR_SET_POS(y);
+	  MPFR_RET(0);
 	}
-      MPFR_SET_POS(y);
-      MPFR_RET(0);
+      MPFR_CLEAR_INF(y);
+      if (MPFR_IS_ZERO(x))
+	return mpfr_set_ui (y, 1, GMP_RNDN);
     }
 
-  MPFR_CLEAR_INF(y);
-
-  if (MPFR_IS_ZERO(x))
-    return mpfr_set_ui (y, 1, GMP_RNDN);
-
   expx = MPFR_GET_EXP (x);
   precy = MPFR_PREC(y);