summaryrefslogtreecommitdiff
path: root/gnulib/lib/sinl.c
diff options
context:
space:
mode:
Diffstat (limited to 'gnulib/lib/sinl.c')
m---------gnulib0
-rw-r--r--gnulib/lib/sinl.c116
2 files changed, 116 insertions, 0 deletions
diff --git a/gnulib b/gnulib
deleted file mode 160000
-Subproject 443bc5ffcf7429e557f4a371b0661abe98ddbc1
diff --git a/gnulib/lib/sinl.c b/gnulib/lib/sinl.c
new file mode 100644
index 0000000..3949e49
--- /dev/null
+++ b/gnulib/lib/sinl.c
@@ -0,0 +1,116 @@
+/* s_sinl.c -- long double version of s_sin.c.
+ * Conversion to long double by Jakub Jelinek, jj@ultra.linux.cz.
+ */
+
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#include <config.h>
+
+/* Specification. */
+#include <math.h>
+
+#if HAVE_SAME_LONG_DOUBLE_AS_DOUBLE
+
+long double
+sinl (long double x)
+{
+ return sin (x);
+}
+
+#else
+
+/* 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
+ *
+ * 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
+ *
+ * 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
+ * ----------------------------------------------------------
+ *
+ * Special cases:
+ * Let trig be any of sin, cos, or tan.
+ * trig(+-INF) is NaN, with signals;
+ * trig(NaN) is that NaN;
+ *
+ * Accuracy:
+ * TRIG(x) returns trig(x) nearly rounded
+ */
+
+# include "trigl.h"
+
+long double
+sinl (long double x)
+{
+ long double y[2], z = 0.0L;
+ int n;
+
+ /* sinl(NaN) is NaN */
+ if (isnanl (x))
+ return x;
+
+ /* |x| ~< pi/4 */
+ if (x >= -0.7853981633974483096156608458198757210492
+ && x <= 0.7853981633974483096156608458198757210492)
+ return kernel_sinl (x, z, 0);
+
+ /* sinl(Inf) is NaN, sinl(0) is 0 */
+ else if (x + x == x)
+ return x - x; /* NaN */
+
+ /* argument reduction needed */
+ else
+ {
+ n = ieee754_rem_pio2l (x, y);
+ switch (n & 3)
+ {
+ case 0:
+ return kernel_sinl (y[0], y[1], 1);
+ case 1:
+ return kernel_cosl (y[0], y[1]);
+ case 2:
+ return -kernel_sinl (y[0], y[1], 1);
+ default:
+ return -kernel_cosl (y[0], y[1]);
+ }
+ }
+}
+
+#endif
+
+#if 0
+int
+main (void)
+{
+ printf ("%.16Lg\n", sinl (0.7853981633974483096156608458198757210492));
+ printf ("%.16Lg\n", sinl (0.7853981633974483096156608458198757210492 *29));
+ printf ("%.16Lg\n", sinl (0.7853981633974483096156608458198757210492 *2));
+ printf ("%.16Lg\n", sinl (0.7853981633974483096156608458198757210492 *30));
+ printf ("%.16Lg\n", sinl (0.7853981633974483096156608458198757210492 *4));
+ printf ("%.16Lg\n", sinl (0.7853981633974483096156608458198757210492 *32));
+ printf ("%.16Lg\n", sinl (0.7853981633974483096156608458198757210492 *2/3));
+ printf ("%.16Lg\n", sinl (0.7853981633974483096156608458198757210492 *4/3));
+}
+#endif