import newlib-2000-02-17 snapshot

1 files changed, 112 insertions, 0 deletions

diff --git a/newlib/libm/mathfp/sf_sine.c b/newlib/libm/mathfp/sf_sine.c
new file mode 100644
index 000000000..6932de26c
--- /dev/null
+++ b/newlib/libm/mathfp/sf_sine.c
@@ -0,0 +1,112 @@
+
+/* @(#)z_sinef.c 1.0 98/08/13 */
+/******************************************************************
+ * The following routines are coded directly from the algorithms
+ * and coefficients given in "Software Manual for the Elementary
+ * Functions" by William J. Cody, Jr. and William Waite, Prentice
+ * Hall, 1980.
+ ******************************************************************/
+/******************************************************************
+ * sine generator
+ *
+ * Input:
+ *   x - floating point value
+ *   cosine - indicates cosine value
+ *
+ * Output:
+ *   Sine of x.
+ *
+ * Description:
+ *   This routine calculates sines and cosines.
+ *
+ *****************************************************************/
+
+#include "fdlibm.h"
+#include "zmath.h"
+
+static const float HALF_PI = 1.570796326;
+static const float ONE_OVER_PI = 0.318309886;
+static const float r[] = { -0.1666665668,
+                            0.8333025139e-02,
+                           -0.1980741872e-03,
+                            0.2601903036e-5 };
+
+float
+_DEFUN (sinef, (float, int),
+        float x _AND
+        int cosine)
+{
+  int sgn, N;
+  float y, XN, g, R, res;
+  float YMAX = 210828714.0;
+
+  switch (numtestf (x))
+    {
+      case NAN:
+        errno = EDOM;
+        return (x);
+      case INF:
+        errno = EDOM;
+        return (z_notanum_f.f); 
+    }
+
+  /* Use sin and cos properties to ease computations. */
+  if (cosine)
+    {
+      sgn = 1;
+      y = fabsf (x) + HALF_PI;
+    }
+  else
+    {
+      if (x < 0.0)
+        {
+          sgn = -1;
+          y = -x;
+        }
+      else
+        {
+          sgn = 1;
+          y = x;
+        }
+    }
+
+  /* Check for values of y that will overflow here. */
+  if (y > YMAX)
+    {
+      errno = ERANGE;
+      return (x);
+    }
+
+  /* Calculate the exponent. */
+  if (y < 0.0)
+    N = (int) (y * ONE_OVER_PI - 0.5);
+  else
+    N = (int) (y * ONE_OVER_PI + 0.5);
+  XN = (float) N;
+
+  if (N & 1)
+    sgn = -sgn;
+
+  if (cosine)
+    XN -= 0.5;
+
+  y = fabsf (x) - XN * __PI;
+
+  if (-z_rooteps_f < y && y < z_rooteps_f)
+    res = y;
+
+  else
+    {
+      g = y * y;
+
+      /* Calculate the Taylor series. */
+      R = (((r[3] * g + r[2]) * g + r[1]) * g + r[0]) * g;
+
+      /* Finally, compute the result. */
+      res = y + y * R;
+    }
+ 
+  res *= sgn;
+
+  return (res);
+}