Use the LBL frexp() on all platforms with ieee floating point.

1 files changed, 50 insertions, 30 deletions

diff --git a/lib/libc/arch/alpha/gen/frexp.c b/lib/libc/arch/alpha/gen/frexp.c
index bf7eeace05b..16665ab5003 100644
--- a/lib/libc/arch/alpha/gen/frexp.c
+++ b/lib/libc/arch/alpha/gen/frexp.c
@@ -1,58 +1,78 @@
-/*	$OpenBSD: frexp.c,v 1.4 1997/07/23 20:55:17 kstailey Exp $	*/
-/*	$NetBSD: frexp.c,v 1.1 1995/02/10 17:50:22 cgd Exp $	*/
+/*	$OpenBSD: frexp.c,v 1.5 2001/09/10 22:37:06 millert Exp $	*/
 
 /*
- * Copyright (c) 1994, 1995 Carnegie-Mellon University.
- * All rights reserved.
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
  *
- * Author: Chris G. Demetriou
- * 
- * Permission to use, copy, modify and distribute this software and
- * its documentation is hereby granted, provided that both the copyright
- * notice and this permission notice appear in all copies of the
- * software, derivative works or modified versions, and any portions
- * thereof, and that both notices appear in supporting documentation.
- * 
- * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 
- * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 
- * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
- * 
- * Carnegie Mellon requests users of this software to return to
+ * This software was developed by the Computer Systems Engineering group
+ * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
+ * contributed to Berkeley.
  *
- *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
- *  School of Computer Science
- *  Carnegie Mellon University
- *  Pittsburgh PA 15213-3890
+ * 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.
  *
- * any improvements or extensions that they make and grant Carnegie the
- * rights to redistribute these changes.
+ * 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 *rcsid = "$OpenBSD: frexp.c,v 1.4 1997/07/23 20:55:17 kstailey Exp $";
+static char rcsid[] = "$OpenBSD: frexp.c,v 1.5 2001/09/10 22:37:06 millert Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/types.h>
 #include <machine/ieee.h>
-#include <math.h>
 
+/*
+ * Split the given value into a fraction in the range [0.5, 1.0) and
+ * an exponent, such that frac * (2^exp) == value.  If value is 0,
+ * return 0.
+ */
 double
 frexp(value, eptr)
 	double value;
 	int *eptr;
 {
-	union doub {
+	union {
 		double v;
 		struct ieee_double s;
 	} u;
 
 	if (value) {
+		/*
+		 * Fractions in [0.5..1.0) have an exponent of 2^-1.
+		 * Leave Inf and NaN alone, however.
+		 * WHAT ABOUT DENORMS?
+		 */
 		u.v = value;
-		*eptr = u.s.dbl_exp - (DBL_EXP_BIAS - 1);
-		u.s.dbl_exp = DBL_EXP_BIAS - 1;
-		return(u.v);
+		if (u.s.dbl_exp != DBL_EXP_INFNAN) {
+			*eptr = u.s.dbl_exp - (DBL_EXP_BIAS - 1);
+			u.s.dbl_exp = DBL_EXP_BIAS - 1;
+		}
+		return (u.v);
 	} else {
 		*eptr = 0;
-		return((double)0);
+		return ((double)0);
 	}
 }