add missing frexp

2 files changed, 76 insertions, 1 deletions

diff --git a/lib/libc/arch/arm/gen/Makefile.inc b/lib/libc/arch/arm/gen/Makefile.inc
index 2730ada96e7..6928132b5b1 100644
--- a/lib/libc/arch/arm/gen/Makefile.inc
+++ b/lib/libc/arch/arm/gen/Makefile.inc
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile.inc,v 1.4 2004/02/02 16:05:53 drahn Exp $
+# $OpenBSD: Makefile.inc,v 1.5 2004/02/02 16:09:45 drahn Exp $
 # $NetBSD: Makefile.inc,v 1.6 2003/08/01 17:03:47 lukem Exp $
 
 SRCS+=	alloca.S byte_swap_2.S byte_swap_4.S divsi3.S \
@@ -13,3 +13,4 @@ SRCS+= isinf.c isnan.c
 
 SRCS+= modf_ieee754.c
 SRCS+= ldexp.c
+SRCS+= frexp.c
diff --git a/lib/libc/arch/arm/gen/frexp.c b/lib/libc/arch/arm/gen/frexp.c
new file mode 100644
index 00000000000..224b643285a
--- /dev/null
+++ b/lib/libc/arch/arm/gen/frexp.c
@@ -0,0 +1,74 @@
+/*	$OpenBSD: frexp.c,v 1.1 2004/02/02 16:09:45 drahn Exp $	*/
+
+/*
+ * Copyright (c) 1992, 1993
+ *	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. 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 rcsid[] = "$OpenBSD: frexp.c,v 1.1 2004/02/02 16:09:45 drahn Exp $";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <machine/ieee.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 {
+		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;
+		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);
+	}
+}