upstream/1.1.0_cvsrelease/1.1.0_cvs

1 files changed, 100 insertions, 0 deletions

diff --git a/lib/libc/quad/fixunssfdi.c b/lib/libc/quad/fixunssfdi.c
new file mode 100644
index 000000000000..85798adb61de
--- /dev/null
+++ b/lib/libc/quad/fixunssfdi.c
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+/*-
+ * Copyright (c) 1992 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This software was developed by the Computer Systems Engineering group
+ * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
+ * contributed to Berkeley.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)fixunssfdi.c	5.2 (Berkeley) 7/13/92";
+#endif /* LIBC_SCCS and not lint */
+
+#include "quad.h"
+
+#define	ONE_FOURTH	(1 << (LONG_BITS - 2))
+#define	ONE_HALF	(ONE_FOURTH * 2.0)
+#define	ONE		(ONE_FOURTH * 4.0)
+
+/*
+ * Convert float to (unsigned) quad.  We do most of our work in double,
+ * out of sheer paranoia.
+ *
+ * Not sure what to do with negative numbers---for now, anything out
+ * of range becomes UQUAD_MAX.
+ *
+ * N.B.: must use new ANSI syntax (sorry).
+ */
+u_quad_t
+__fixunssfdi(float f)
+{
+	double x, toppart;
+	union uu t;
+
+	if (f < 0)
+		return (UQUAD_MAX);	/* ??? should be 0?  ERANGE??? */
+#ifdef notdef				/* this falls afoul of a GCC bug */
+	if (f >= UQUAD_MAX)
+		return (UQUAD_MAX);
+#else					/* so we wire in 2^64-1 instead */
+	if (f >= 18446744073709551615.0)
+		return (UQUAD_MAX);
+#endif
+	x = f;
+	/*
+	 * Get the upper part of the result.  Note that the divide
+	 * may round up; we want to avoid this if possible, so we
+	 * subtract `1/2' first.
+	 */
+	toppart = (x - ONE_HALF) / ONE;
+	/*
+	 * Now build a u_quad_t out of the top part.  The difference
+	 * between x and this is the bottom part (this may introduce
+	 * a few fuzzy bits, but what the heck).  With any luck this
+	 * difference will be nonnegative: x should wind up in the
+	 * range [0..ULONG_MAX].  For paranoia, we assume [LONG_MIN..
+	 * 2*ULONG_MAX] instead.
+	 */
+	t.ul[H] = (unsigned long)toppart;
+	t.ul[L] = 0;
+	x -= (double)t.uq;
+	if (x < 0) {
+		t.ul[H]--;
+		x += ULONG_MAX;
+	}
+	if (x > ULONG_MAX) {
+		t.ul[H]++;
+		x -= ULONG_MAX;
+	}
+	t.ul[L] = (u_long)x;
+	return (t.uq);
+}