* device/lib/pic/libm: NEW, added math library functions

[fw/sdcc] / device / lib / pic / libm / asincosf.c

diff --git a/device/lib/pic/libm/asincosf.c b/device/lib/pic/libm/asincosf.c
new file mode 100644 (file)
index 0000000..cad72b7
--- /dev/null
+++ b/device/lib/pic/libm/asincosf.c
@@ -0,0 +1,86 @@
+/*  asincosf.c: Computes asin or acos of a 32-bit float as outlined in [1]
+
+    Copyright (C) 2001, 2002  Jesus Calvino-Fraga, jesusc@ieee.org 
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA */
+
+/* [1] William James Cody and W.  M.  Waite.  _Software manual for the
+   elementary functions_, Englewood Cliffs, N.J.:Prentice-Hall, 1980. */
+
+/* Version 1.0 - Initial release */
+
+/*
+** $Id: asincosf.c 3654 2005-01-24 10:38:53Z vrokas $
+*/
+
+
+#include <math.h>
+#include <errno.h>
+
+#define P1  0.933935835E+0
+#define P2 -0.504400557E+0
+#define Q0  0.560363004E+1
+#define Q1 -0.554846723E+1
+#define Q2  0.100000000E+1
+
+#define P(g) (P2*g+P1)
+#define Q(g) ((Q2*g+Q1)*g+Q0)
+
+float asincosf(const float x, const int isacos)
+{
+    float y, g, r;
+    int i;
+
+    static const float a[2]={ 0.0, QUART_PI };
+    static const float b[2]={ HALF_PI, QUART_PI };
+
+    y=fabsf(x);
+    i=isacos;
+    if (y < EPS) r=y;
+    else
+    {
+        if (y > 0.5)
+        {
+            i=1-i;
+            if (y > 1.0)
+            {
+                errno=EDOM;
+                return 0.0;
+            }
+            g=(0.5-y)+0.5;
+            g=ldexpf(g,-1);
+            y=sqrtf(g);
+            y=-(y+y);
+        }
+        else
+        {
+            g=y*y;
+        }
+        r=y+y*((P(g)*g)/Q(g));
+    }
+    if (isacos)
+    {
+        if (x < 0.0)
+            r=(b[i]+r)+b[i];
+        else
+            r=(a[i]-r)+a[i];
+    }
+    else
+    {
+        r=(a[i]+r)+a[i];
+        if (x<0.0) r=-r;
+    }
+    return r;
+}