ceil-ieee tests: More tests.

[gnulib.git] / lib / expl.c

diff --git a/lib/expl.c b/lib/expl.c
index 7c3c5ec..c70f445 100644 (file)
--- a/lib/expl.c
+++ b/lib/expl.c
@@ -1,37 +1,48 @@
 /* Emulation for expl.
    Contributed by Paolo Bonzini
 
-   Copyright 2002, 2003 Free Software Foundation, Inc.
+   Copyright 2002-2003, 2007, 2009-2012 Free Software Foundation, Inc.
 
    This file is part of gnulib.
 
-   This program is free software; you can redistribute it and/or modify
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
-   You should have received a copy of the GNU General Public License along
-   with this program; if not, write to the Free Software Foundation,
-   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#include <float.h>
+#include <config.h>
+
+/* Specification.  */
 #include <math.h>
 
-#include "mathl.h"
+#if HAVE_SAME_LONG_DOUBLE_AS_DOUBLE
+
+long double
+expl (long double x)
+{
+  return exp (x);
+}
+
+#else
+
+# include <float.h>
 
 static const long double C[] = {
-/* Chebyshev polynom coeficients for (exp(x)-1)/x */
-#define P1 C[0]
-#define P2 C[1]
-#define P3 C[2]
-#define P4 C[3]
-#define P5 C[4]
-#define P6 C[5]
+/* Chebyshev polynomial coefficients for (exp(x)-1)/x */
+# define P1 C[0]
+# define P2 C[1]
+# define P3 C[2]
+# define P4 C[3]
+# define P5 C[4]
+# define P6 C[5]
  0.5L,
  1.66666666666666666666666666666666683E-01L,
  4.16666666666666666666654902320001674E-02L,
@@ -40,19 +51,19 @@ static const long double C[] = {
  1.98412698413981650382436541785404286E-04L,
 
 /* Smallest integer x for which e^x overflows.  */
-#define himark C[6]
+# define himark C[6]
  11356.523406294143949491931077970765L,
 
 /* Largest integer x for which e^x underflows.  */
-#define lomark C[7]
+# define lomark C[7]
 -11433.4627433362978788372438434526231L,
 
 /* very small number */
-#define TINY C[8]
+# define TINY C[8]
  1.0e-4900L,
 
 /* 2^16383 */
-#define TWO16383 C[9]
+# define TWO16383 C[9]
  5.94865747678615882542879663314003565E+4931L};
 
 long double
@@ -71,16 +82,16 @@ expl (long double x)
       x -= exponent / 8.0L;
 
       if (x > 0.0625)
-       {
-         exponent++;
-         x -= 0.125L;
-       }
+        {
+          exponent++;
+          x -= 0.125L;
+        }
 
       if (exponent < 0)
         {
           t = 0.8824969025845954028648921432290507362220L; /* e^-0.25 */
-         exponent = -exponent;
-       }
+          exponent = -exponent;
+        }
       else
         t = 1.1331484530668263168290072278117938725655L; /* e^0.25 */
 
@@ -96,8 +107,8 @@ expl (long double x)
         }
 
       /* Approximate (e^x - 1)/x, using a seventh-degree polynomial,
-        with maximum error in [-2^-16-2^-53,2^-16+2^-53]
-        less than 4.8e-39.  */
+         with maximum error in [-2^-16-2^-53,2^-16+2^-53]
+         less than 4.8e-39.  */
       x22 = x + x*x*(P1+x*(P2+x*(P3+x*(P4+x*(P5+x*P6)))));
 
       return result + result * x22;
@@ -106,29 +117,31 @@ expl (long double x)
   else if (x < himark)
     {
       if (x + x == x)
-       /* e^-inf == 0, with no error.  */
-       return 0;
+        /* e^-inf == 0, with no error.  */
+        return 0;
       else
-       /* Underflow */
-       return TINY * TINY;
+        /* Underflow */
+        return TINY * TINY;
     }
   else
     /* Return x, if x is a NaN or Inf; or overflow, otherwise.  */
     return TWO16383*x;
 }
 
+#endif
+
 #if 0
 int
-main ()
+main (void)
 {
-  printf ("%.16Lg\n", expl(1.0L));
-  printf ("%.16Lg\n", expl(-1.0L));
-  printf ("%.16Lg\n", expl(2.0L));
-  printf ("%.16Lg\n", expl(4.0L));
-  printf ("%.16Lg\n", expl(-2.0L));
-  printf ("%.16Lg\n", expl(-4.0L));
-  printf ("%.16Lg\n", expl(0.0625L));
-  printf ("%.16Lg\n", expl(0.3L));
-  printf ("%.16Lg\n", expl(0.6L));
+  printf ("%.16Lg\n", expl (1.0L));
+  printf ("%.16Lg\n", expl (-1.0L));
+  printf ("%.16Lg\n", expl (2.0L));
+  printf ("%.16Lg\n", expl (4.0L));
+  printf ("%.16Lg\n", expl (-2.0L));
+  printf ("%.16Lg\n", expl (-4.0L));
+  printf ("%.16Lg\n", expl (0.0625L));
+  printf ("%.16Lg\n", expl (0.3L));
+  printf ("%.16Lg\n", expl (0.6L));
 }
 #endif