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+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Mozilla Communicator client code, released
+ * March 31, 1998.
+ *
+ * The Initial Developer of the Original Code is
+ * Sun Microsystems, Inc.
+ * Portions created by the Initial Developer are Copyright (C) 1998
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either of the GNU General Public License Version 2 or later (the "GPL"),
+ * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+/* @(#)s_floor.c 1.3 95/01/18 */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunSoft, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+/*
+ * floor(x)
+ * Return x rounded toward -inf to integral value
+ * Method:
+ * Bit twiddling.
+ * Exception:
+ * Inexact flag raised if x not equal to floor(x).
+ */
+
+#include "fdlibm.h"
+
+#ifdef __STDC__
+static const double really_big = 1.0e300;
+#else
+static double really_big = 1.0e300;
+#endif
+
+#ifdef __STDC__
+ double fd_floor(double x)
+#else
+ double fd_floor(x)
+ double x;
+#endif
+{
+ fd_twoints u;
+ int i0,i1,j0;
+ unsigned i,j;
+ u.d = x;
+ i0 = __HI(u);
+ i1 = __LO(u);
+ j0 = ((i0>>20)&0x7ff)-0x3ff;
+ if(j0<20) {
+ if(j0<0) { /* raise inexact if x != 0 */
+ if(really_big+x>0.0) {/* return 0*sign(x) if |x|<1 */
+ if(i0>=0) {i0=i1=0;}
+ else if(((i0&0x7fffffff)|i1)!=0)
+ { i0=0xbff00000;i1=0;}
+ }
+ } else {
+ i = (0x000fffff)>>j0;
+ if(((i0&i)|i1)==0) return x; /* x is integral */
+ if(really_big+x>0.0) { /* raise inexact flag */
+ if(i0<0) i0 += (0x00100000)>>j0;
+ i0 &= (~i); i1=0;
+ }
+ }
+ } else if (j0>51) {
+ if(j0==0x400) return x+x; /* inf or NaN */
+ else return x; /* x is integral */
+ } else {
+ i = ((unsigned)(0xffffffff))>>(j0-20);
+ if((i1&i)==0) return x; /* x is integral */
+ if(really_big+x>0.0) { /* raise inexact flag */
+ if(i0<0) {
+ if(j0==20) i0+=1;
+ else {
+ j = i1+(1<<(52-j0));
+ if((int)j<i1) i0 +=1 ; /* got a carry */
+ i1=j;
+ }
+ }
+ i1 &= (~i);
+ }
+ }
+ u.d = x;
+ __HI(u) = i0;
+ __LO(u) = i1;
+ x = u.d;
+ return x;
+}