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-rw-r--r--sysdeps/m68k/fpu/e_atan2.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/sysdeps/m68k/fpu/e_atan2.c b/sysdeps/m68k/fpu/e_atan2.c
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+/* Copyright (C) 1997, 1999 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 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.
+
+   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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <math.h>
+#include "math_private.h"
+#include "mathimpl.h"
+
+#ifndef SUFF
+#define SUFF
+#endif
+#ifndef float_type
+#define float_type double
+#endif
+
+#define CONCATX(a,b) __CONCAT(a,b)
+#define s(name) CONCATX(name,SUFF)
+#define m81(func) __m81_u(s(func))
+
+float_type
+s(__ieee754_atan2) (float_type y, float_type x)
+{
+  float_type pi, pi_2, z;
+  unsigned long y_cond, x_cond;
+
+  __asm ("fmovecr%.x %#0, %0" : "=f" (pi));
+  __asm ("fscale%.w %#-1, %0" : "=f" (pi_2) : "0" (pi));
+  y_cond = __m81_test (y);
+  x_cond = __m81_test (x);
+
+  if ((x_cond | y_cond) & __M81_COND_NAN)
+    z = x + y;
+  else if (y_cond & __M81_COND_ZERO)
+    {
+      if (x_cond & __M81_COND_NEG)
+	z = y_cond & __M81_COND_NEG ? -pi : pi;
+      else
+	z = y;
+    }
+  else if (x_cond & __M81_COND_INF)
+    {
+      if (y_cond & __M81_COND_INF)
+	{
+	  float_type pi_4;
+	  __asm ("fscale%.w %#-2, %0" : "=f" (pi_4) : "0" (pi));
+	  z = x_cond & __M81_COND_NEG ? 3 * pi_4 : pi_4;
+	}
+      else
+	z = x_cond & __M81_COND_NEG ? pi : 0;
+      if (y_cond & __M81_COND_NEG)
+	z = -z;
+    }
+  else if (y_cond & __M81_COND_INF)
+    z = y_cond & __M81_COND_NEG ? -pi_2 : pi_2;
+  else if (x_cond & __M81_COND_NEG)
+    {
+      if (y_cond & __M81_COND_NEG)
+	{
+	  if (-x > -y)
+	    z = -pi + m81(__atan) (y / x);
+	  else
+	    z = -pi_2 - m81(__atan) (x / y);
+	}
+      else
+	{
+	  if (-x > y)
+	    z = pi + m81(__atan) (y / x);
+	  else
+	    z = pi_2 - m81(__atan) (x / y);
+	}
+    }
+  else
+    {
+      if (y_cond & __M81_COND_NEG)
+	{
+	  if (x > -y)
+	    z = m81(__atan) (y / x);
+	  else
+	    z = -pi_2 - m81(__atan) (x / y);
+	}
+      else
+	{
+	  if (x > y)
+	    z = m81(__atan) (y / x);
+	  else
+	    z = pi_2 - m81(__atan) (x / y);
+	}
+    }
+  return z;
+}