* ====================================================
*/
+#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 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);
- /* sinl(Inf or NaN) is NaN, sinl(0) is 0 */
- else if ((x + x == x && x != 0.0) || x != x)
+ /* 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);
+ 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));