patch-2.4.6 linux/arch/mips64/math-emu/dp_modf.c
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- Lines: 81
- Date:
Mon Jul 2 13:56:40 2001
- Orig file:
v2.4.5/linux/arch/mips64/math-emu/dp_modf.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -u --recursive --new-file v2.4.5/linux/arch/mips64/math-emu/dp_modf.c linux/arch/mips64/math-emu/dp_modf.c
@@ -0,0 +1,80 @@
+/* IEEE754 floating point arithmetic
+ * double precision: common utilities
+ */
+/*
+ * MIPS floating point support
+ * Copyright (C) 1994-2000 Algorithmics Ltd. All rights reserved.
+ * http://www.algor.co.uk
+ *
+ * ########################################################################
+ *
+ * This program is free software; you can distribute it and/or modify it
+ * under the terms of the GNU General Public License (Version 2) as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * ########################################################################
+ */
+
+
+#include "ieee754dp.h"
+
+/* modf function is always exact for a finite number
+*/
+ieee754dp ieee754dp_modf(ieee754dp x, ieee754dp * ip)
+{
+ COMPXDP;
+
+ CLEARCX;
+
+ EXPLODEXDP;
+
+ switch (xc) {
+ case IEEE754_CLASS_SNAN:
+ case IEEE754_CLASS_QNAN:
+ case IEEE754_CLASS_INF:
+ case IEEE754_CLASS_ZERO:
+ *ip = x;
+ return x;
+ case IEEE754_CLASS_DNORM:
+ /* far to small */
+ *ip = ieee754dp_zero(xs);
+ return x;
+ case IEEE754_CLASS_NORM:
+ break;
+ }
+ if (xe < 0) {
+ *ip = ieee754dp_zero(xs);
+ return x;
+ }
+ if (xe >= DP_MBITS) {
+ *ip = x;
+ return ieee754dp_zero(xs);
+ }
+ /* generate ipart mantissa by clearing bottom bits
+ */
+ *ip = builddp(xs, xe + DP_EBIAS,
+ ((xm >> (DP_MBITS - xe)) << (DP_MBITS - xe)) &
+ ~DP_HIDDEN_BIT);
+
+ /* generate fpart mantissa by clearing top bits
+ * and normalizing (must be able to normalize)
+ */
+ xm = (xm << (64 - (DP_MBITS - xe))) >> (64 - (DP_MBITS - xe));
+ if (xm == 0)
+ return ieee754dp_zero(xs);
+
+ while ((xm >> DP_MBITS) == 0) {
+ xm <<= 1;
+ xe--;
+ }
+ return builddp(xs, xe + DP_EBIAS, xm & ~DP_HIDDEN_BIT);
+}
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