gettimeofday: port recent C++ fix to Emacs

[gnulib.git] / lib / cosl.c

diff --git a/lib/cosl.c b/lib/cosl.c
index 1c208ad..d448548 100644 (file)
--- a/lib/cosl.c
+++ b/lib/cosl.c
@@ -13,26 +13,43 @@
  * ====================================================
  */
 
-/* sinl(x)
- * Return sine function of x.
+#include <config.h>
+
+/* Specification.  */
+#include <math.h>
+
+#if HAVE_SAME_LONG_DOUBLE_AS_DOUBLE
+
+long double
+cosl (long double x)
+{
+  return cos (x);
+}
+
+#else
+
+/* Code based on glibc/sysdeps/ieee754/ldbl-128/s_cosl.c.  */
+
+/* cosl(x)
+ * Return cosine function of x.
  *
  * kernel function:
- *     __kernel_sinl           ... sine function on [-pi/4,pi/4]
- *     __kernel_cosl           ... cose function on [-pi/4,pi/4]
- *     __ieee754_rem_pio2l     ... argument reduction routine
+ *      __kernel_sinl           ... sine function on [-pi/4,pi/4]
+ *      __kernel_cosl           ... cosine function on [-pi/4,pi/4]
+ *      __ieee754_rem_pio2l     ... argument reduction routine
  *
  * Method.
  *      Let S,C and T denote the sin, cos and tan respectively on
- *     [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2
- *     in [-pi/4 , +pi/4], and let n = k mod 4.
- *     We have
+ *      [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2
+ *      in [-pi/4 , +pi/4], and let n = k mod 4.
+ *      We have
  *
  *          n        sin(x)      cos(x)        tan(x)
  *     ----------------------------------------------------------
- *         0          S           C             T
- *         1          C          -S            -1/T
- *         2         -S          -C             T
- *         3         -C           S            -1/T
+ *          0          S           C             T
+ *          1          C          -S            -1/T
+ *          2         -S          -C             T
+ *          3         -C           S            -1/T
  *     ----------------------------------------------------------
  *
  * Special cases:
@@ -41,57 +58,61 @@
  *      trig(NaN)    is that NaN;
  *
  * Accuracy:
- *     TRIG(x) returns trig(x) nearly rounded
+ *      TRIG(x) returns trig(x) nearly rounded
  */
 
-#include <math.h>
+# include "trigl.h"
 
-#include "mathl.h"
+long double
+cosl (long double x)
+{
+  long double y[2],z=0.0L;
+  int n;
 
-#include "trigl.h"
-#ifdef HAVE_SINL
-#include "trigl.c"
-#include "sincosl.c"
-#endif
+  /* cosl(NaN) is NaN */
+  if (isnanl (x))
+    return x;
 
-long double cosl(long double x)
-{
-       long double y[2],z=0.0L;
-       int n;
-
-    /* |x| ~< pi/4 */
-        if(x >= -0.7853981633974483096156608458198757210492 &&
-           x <= 0.7853981633974483096156608458198757210492)
-          return kernel_cosl(x, z);
-
-    /* sinl(Inf or NaN) is NaN, sinl(0) is 0 */
-        else if ((x + x == x && x != 0.0) || x != x)
-          return x-x;           /* NaN */
-
-    /* argument reduction needed */
-       else {
-           n = ieee754_rem_pio2l(x,y);
-            switch(n&3) {
-                case 0: return  kernel_cosl(y[0],y[1]);
-                case 1: return -kernel_sinl(y[0],y[1],1);
-                case 2: return -kernel_cosl(y[0],y[1]);
-                default:
-                        return  kernel_sinl(y[0],y[1],1);
-           }
-       }
+  /* |x| ~< pi/4 */
+  if (x >= -0.7853981633974483096156608458198757210492
+      && x <= 0.7853981633974483096156608458198757210492)
+    return kernel_cosl(x, z);
+
+  /* cosl(Inf) is NaN, cosl(0) is 1 */
+  else if (x + x == x && x != 0.0)
+    return x - x;           /* NaN */
+
+  /* argument reduction needed */
+  else
+    {
+      n = ieee754_rem_pio2l (x, y);
+      switch (n & 3)
+        {
+        case 0:
+          return  kernel_cosl (y[0], y[1]);
+        case 1:
+          return -kernel_sinl (y[0], y[1], 1);
+        case 2:
+          return -kernel_cosl (y[0], y[1]);
+        default:
+          return  kernel_sinl (y[0], y[1], 1);
+        }
+    }
 }
 
+#endif
+
 #if 0
 int
 main (void)
 {
-  printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492));
-  printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *29));
-  printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *2));
-  printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *30));
-  printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *4));
-  printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *32));
-  printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *2/3));
-  printf ("%.16Lg\n", cosl(0.7853981633974483096156608458198757210492 *4/3));
+  printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492));
+  printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *29));
+  printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *2));
+  printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *30));
+  printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *4));
+  printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *32));
+  printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *2/3));
+  printf ("%.16Lg\n", cosl (0.7853981633974483096156608458198757210492 *4/3));
 }
 #endif