* ====================================================
*/
+#include <config.h>
+
+/* Specification. */
+#include <math.h>
+
/* sinl(x)
* Return sine 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 ... cose 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:
* trig(NaN) is that NaN;
*
* Accuracy:
- * TRIG(x) returns trig(x) nearly rounded
+ * TRIG(x) returns trig(x) nearly rounded
*/
-#include <math.h>
-
-#include "mathl.h"
-
#include "trigl.h"
-#ifdef HAVE_SINL
-#include "trigl.c"
-#include "sincosl.c"
-#endif
-long double cosl(long double x)
+long double
+cosl (long double x)
{
- long double y[2],z=0.0L;
- int n;
+ long double y[2],z=0.0L;
+ int n;
+
+ /* cosl(NaN) is NaN */
+ if (isnanl (x))
+ return x;
- /* |x| ~< pi/4 */
- if(x >= -0.7853981633974483096156608458198757210492 &&
- x <= 0.7853981633974483096156608458198757210492)
- return kernel_cosl(x, z);
+ /* |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 */
+ /* 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);
- }
- }
+ /* 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);
+ }
+ }
}
#if 0
int
-main ()
+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