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-rw-r--r--lib/libc/gen/frexp.c79
1 files changed, 79 insertions, 0 deletions
diff --git a/lib/libc/gen/frexp.c b/lib/libc/gen/frexp.c
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+++ b/lib/libc/gen/frexp.c
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+/* $OpenBSD: frexp.c,v 1.7 2011/07/08 22:28:33 martynas Exp $ */
+
+/*-
+ * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
+ * All rights reserved.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ * $FreeBSD: frexp.c,v 1.1 2004/07/18 21:23:39 das Exp $
+ */
+
+/* LINTLIBRARY */
+
+#include <sys/types.h>
+#include <sys/cdefs.h>
+#include <machine/ieee.h>
+#include <float.h>
+#include <math.h>
+
+double
+frexp(double v, int *ex)
+{
+ union {
+ double v;
+ struct ieee_double s;
+ } u;
+
+ u.v = v;
+ switch (u.s.dbl_exp) {
+ case 0: /* 0 or subnormal */
+ if ((u.s.dbl_fracl | u.s.dbl_frach) == 0) {
+ *ex = 0;
+ } else {
+ /*
+ * The power of 2 is arbitrary, any value from 54 to
+ * 1024 will do.
+ */
+ u.v *= 0x1.0p514;
+ *ex = u.s.dbl_exp - (DBL_EXP_BIAS - 1 + 514);
+ u.s.dbl_exp = DBL_EXP_BIAS - 1;
+ }
+ break;
+ case DBL_EXP_INFNAN: /* Inf or NaN; value of *ex is unspecified */
+ break;
+ default: /* normal */
+ *ex = u.s.dbl_exp - (DBL_EXP_BIAS - 1);
+ u.s.dbl_exp = DBL_EXP_BIAS - 1;
+ break;
+ }
+ return (u.v);
+}
+
+#if LDBL_MANT_DIG == 53
+#ifdef lint
+/* PROTOLIB1 */
+long double frexpl(long double, int *);
+#else /* lint */
+__weak_alias(frexpl, frexp);
+#endif /* lint */
+#endif /* LDBL_MANT_DIG == 53 */