Initial revision

diff --git a/sysdeps/m68k/fpu/atan2.c b/sysdeps/m68k/fpu/atan2.c
new file mode 100644 (file)
index 0000000..1dfffe7
--- /dev/null
+++ b/sysdeps/m68k/fpu/atan2.c
@@ -0,0 +1,68 @@
+/* Copyright (C) 1991 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <ansidecl.h>
+#include <math.h>
+
+static CONST double 
+PIo4   =  7.8539816339744827900E-1    , /*Hex  2^ -1   *  1.921FB54442D18 */
+PIo2   =  1.5707963267948965580E0     , /*Hex  2^  0   *  1.921FB54442D18 */
+PI     =  3.1415926535897931160E0     ; /*Hex  2^  1   *  1.921FB54442D18 */
+
+double
+DEFUN(atan2, (y, x), double y AND double x)
+{
+  static CONST double one = 1.0, zero = 0.0;
+  double signx, signy;
+  double pi;
+
+  if (__isnan(x))
+    return x;
+  if (__isnan(y))
+    return y;
+
+  signy = __copysign(one, y);
+  signx = __copysign(one, x);
+
+  asm("fmovecr%.x %1, %0" : "=f" (pi) : "i" (0));
+
+  if (y == zero)
+    return signx == one ? y : __copysign(pi, signy);
+
+  if (x == zero)
+    return __copysign(PIo2, signy);
+
+  if (__isinf(x))
+    {
+      if (__isinf(y))
+       return __copysign(signx == one ? PIo4 : 3 * PIo4, signy);
+      else
+       return __copysign(signx == one ? zero : pi, signy);
+    }
+
+  if (__isinf(y))
+    return __copysign(PIo2, signy);
+
+  y = fabs(y);
+
+  if (x < 0.0)
+    /* X is negative.  */
+    return __copysign(pi - atan(y / -x), signy);
+
+  return __copysign(atan(y / x), signy);
+}