patch-2.4.6 linux/arch/mips64/math-emu/dp_tlong.c

• Lines: 142
• Date: Mon Jul 2 13:56:41 2001
• Orig file: v2.4.5/linux/arch/mips64/math-emu/dp_tlong.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.5/linux/arch/mips64/math-emu/dp_tlong.c linux/arch/mips64/math-emu/dp_tlong.c
@@ -0,0 +1,141 @@
+/* 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"
+
+long long ieee754dp_tlong(ieee754dp x)
+{
+	COMPXDP;
+
+	CLEARCX;
+
+	EXPLODEXDP;
+
+	switch (xc) {
+	case IEEE754_CLASS_SNAN:
+	case IEEE754_CLASS_QNAN:
+		SETCX(IEEE754_INVALID_OPERATION);
+		return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x);
+	case IEEE754_CLASS_INF:
+		SETCX(IEEE754_OVERFLOW);
+		return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x);
+	case IEEE754_CLASS_ZERO:
+		return 0;
+	case IEEE754_CLASS_DNORM:	/* much too small */
+		SETCX(IEEE754_UNDERFLOW);
+		return ieee754di_xcpt(0, "dp_tlong", x);
+	case IEEE754_CLASS_NORM:
+		break;
+	}
+	if (xe >= 63) {
+		SETCX(IEEE754_OVERFLOW);
+		return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x);
+	}
+	if (xe < 0) {
+		if (ieee754_csr.rm == IEEE754_RU) {
+			if (xs) {	/* Negative  */
+				return 0x0000000000000000LL;
+			} else {	/* Positive */
+				return 0x0000000000000001LL;
+			}
+		} else if (ieee754_csr.rm == IEEE754_RD) {
+			if (xs) {	/* Negative , return -1 */
+				return 0xffffffffffffffffLL;
+			} else {	/* Positive */
+				return 0x0000000000000000LL;
+			}
+		} else {
+			SETCX(IEEE754_UNDERFLOW);
+			return ieee754di_xcpt(0, "dp_tlong", x);
+		}
+	}
+	/* oh gawd */
+	if (xe > DP_MBITS) {
+		xm <<= xe - DP_MBITS;
+	} else if (xe < DP_MBITS) {
+		unsigned long long residue;
+		unsigned long long mask = 0;
+		int i;
+		int round;
+		int sticky;
+		int odd;
+
+		/* compute mask */
+		for (i = 0; i < DP_MBITS - xe; i++) {
+			mask = mask << 1;
+			mask = mask | 0x1;
+		}
+		residue = (xm & mask) << (64 - (DP_MBITS - xe));
+		round =
+		    ((0x8000000000000000LL & residue) !=
+		     0x0000000000000000LL);
+		sticky =
+		    ((0x7fffffffffffffffLL & residue) !=
+		     0x0000000000000000LL);
+
+		xm >>= DP_MBITS - xe;
+
+		odd = ((xm & 0x1) != 0x0000000000000000LL);
+
+		/* Do the rounding */
+		if (!round && sticky) {
+			if ((ieee754_csr.rm == IEEE754_RU && !xs)
+			    || (ieee754_csr.rm == IEEE754_RD && xs)) {
+				xm++;
+			}
+		} else if (round && !sticky) {
+			if ((ieee754_csr.rm == IEEE754_RU && !xs)
+			    || (ieee754_csr.rm == IEEE754_RD && xs)
+			    || (ieee754_csr.rm == IEEE754_RN && odd)) {
+				xm++;
+			}
+		} else if (round && sticky) {
+			if ((ieee754_csr.rm == IEEE754_RU && !xs)
+			    || (ieee754_csr.rm == IEEE754_RD && xs)
+			    || (ieee754_csr.rm == IEEE754_RN)) {
+				xm++;
+			}
+		}
+	}
+	if (xs)
+		return -xm;
+	else
+		return xm;
+}
+
+
+unsigned long long ieee754dp_tulong(ieee754dp x)
+{
+	ieee754dp hb = ieee754dp_1e63();
+
+	/* what if x < 0 ?? */
+	if (ieee754dp_lt(x, hb))
+		return (unsigned long long) ieee754dp_tlong(x);
+
+	return (unsigned long long) ieee754dp_tlong(ieee754dp_sub(x, hb)) |
+	    (1ULL << 63);
+}