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+/* Copyright (C) 1992, 1995 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. */
+
+/*
+ * Copyright (c) 1985 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted provided
+ * that: (1) source distributions retain this entire copyright notice and
+ * comment, and (2) distributions including binaries display the following
+ * acknowledgement: ``This product includes software developed by the
+ * University of California, Berkeley and its contributors'' in the
+ * documentation or other materials provided with the distribution and in
+ * all advertising materials mentioning features or use of this software.
+ * Neither the name of the University nor the names of its contributors may
+ * be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#include <ansidecl.h>
+#include <math.h>
+#include <float.h>
+#include "ieee754.h"
+
+/* Return the remainder of X/Y. */
+double
+DEFUN(__drem, (x, y),
+ double x AND double y)
+{
+ union ieee754_double ux, uy;
+
+ ux.d = x;
+ uy.d = y;
+#define x ux.d
+#define y uy.d
+
+ uy.ieee.negative = 0;
+
+ if (!__finite (x) || y == 0.0)
+ return NAN;
+ else if (__isnan (y))
+ return y;
+ else if (__isinf (y))
+ return x;
+ else if (uy.ieee.exponent <= 1)
+ {
+ /* Subnormal (or almost subnormal) Y value. */
+ double b = __scalb (1.0, 54);
+ y *= b;
+ x = __drem (x, y);
+ x *= b;
+ return __drem (x, y) / b;
+ }
+ else if (y >= 1.7e308 / 2)
+ {
+ y /= 2;
+ x /= 2;
+ return __drem (x, y) * 2;
+ }
+ else
+ {
+ union ieee754_double a;
+ double b;
+ unsigned int negative = ux.ieee.negative;
+ a.d = y + y;
+ b = y / 2;
+ ux.ieee.negative = 0;
+ while (x > a.d)
+ {
+ unsigned short int k = ux.ieee.exponent - a.ieee.exponent;
+ union ieee754_double tmp;
+ tmp.d = a.d;
+ tmp.ieee.exponent += k;
+ if (x < tmp.d)
+ --tmp.ieee.exponent;
+ x -= tmp.d;
+ }
+ if (x > b)
+ {
+ x -= y;
+ if (x >= b)
+ x -= y;
+ }
+ ux.ieee.negative ^= negative;
+ return x;
+ }
+}
+
+weak_alias (__drem, drem)