From 28f540f45bbacd939bfd07f213bcad2bf730b1bf Mon Sep 17 00:00:00 2001
From: Roland McGrath <roland@gnu.org>
Date: Sat, 18 Feb 1995 01:27:10 +0000
Subject: initial import

---
 sysdeps/m68k/fpu/atan2.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)
 create mode 100644 sysdeps/m68k/fpu/atan2.c

(limited to 'sysdeps/m68k/fpu/atan2.c')

diff --git a/sysdeps/m68k/fpu/atan2.c b/sysdeps/m68k/fpu/atan2.c
new file mode 100644
index 0000000000..1efdb1f7a6
--- /dev/null
+++ b/sysdeps/m68k/fpu/atan2.c
@@ -0,0 +1,71 @@
+/* Copyright (C) 1991, 1992, 1994 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>
+
+#ifdef	__GNUC__
+
+__CONSTVALUE double
+DEFUN(atan2, (y, x), double y AND double x)
+{
+  static CONST double one = 1.0, zero = 0.0;
+  double signx, signy;
+  double pi, PIo4, PIo2;
+
+  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));
+  PIo2 = pi / 2;
+  PIo4 = pi / 4;
+
+  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);
+}
+
+#else
+#include <sysdeps/generic/atan2.c>
+#endif
-- 
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