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authorjoerg <joerg@NetBSD.org>2011-07-26 16:10:15 +0000
committerjoerg <joerg@NetBSD.org>2011-07-26 16:10:15 +0000
commitf363aaa8561cd43a8f7ceafe0a31bfc2b5740545 (patch)
treeaf2788e152e53b28cd5a5c71524d1240d0317728 /lib/libm/src
parentc8fc07cf75ebd25d6811851404585a9c6ce0d99f (diff)
Add scalbnl to libm.
Diffstat (limited to 'lib/libm/src')
-rw-r--r--lib/libm/src/namespace.h3
-rw-r--r--lib/libm/src/s_scalbn.c7
-rw-r--r--lib/libm/src/s_scalbnl.c106
3 files changed, 114 insertions, 2 deletions
diff --git a/lib/libm/src/namespace.h b/lib/libm/src/namespace.h
index a2d39e47938..702df101d85 100644
--- a/lib/libm/src/namespace.h
+++ b/lib/libm/src/namespace.h
@@ -1,4 +1,4 @@
-/* $NetBSD: namespace.h,v 1.3 2010/04/23 19:17:07 drochner Exp $ */
+/* $NetBSD: namespace.h,v 1.4 2011/07/26 16:10:16 joerg Exp $ */
#define atan2 _atan2
#define atan2f _atan2f
@@ -32,3 +32,4 @@
#define scalbn _scalbn
#define scalbnf _scalbnf
+#define scalbnl _scalbnl
diff --git a/lib/libm/src/s_scalbn.c b/lib/libm/src/s_scalbn.c
index f8b2f8c3a59..f6c5baf11dd 100644
--- a/lib/libm/src/s_scalbn.c
+++ b/lib/libm/src/s_scalbn.c
@@ -12,7 +12,7 @@
#include <sys/cdefs.h>
#if defined(LIBM_SCCS) && !defined(lint)
-__RCSID("$NetBSD: s_scalbn.c,v 1.14 2010/04/23 19:17:07 drochner Exp $");
+__RCSID("$NetBSD: s_scalbn.c,v 1.15 2011/07/26 16:10:16 joerg Exp $");
#endif
/*
@@ -26,6 +26,11 @@ __RCSID("$NetBSD: s_scalbn.c,v 1.14 2010/04/23 19:17:07 drochner Exp $");
#include "math.h"
#include "math_private.h"
+#ifndef __HAVE_LONG_DOUBLE
+__strong_alias(_scalbnl, _scalbn)
+__weak_alias(scalbnl, _scalbnl)
+#endif
+
#ifdef __weak_alias
__weak_alias(scalbn, _scalbn)
#endif
diff --git a/lib/libm/src/s_scalbnl.c b/lib/libm/src/s_scalbnl.c
new file mode 100644
index 00000000000..d638e254073
--- /dev/null
+++ b/lib/libm/src/s_scalbnl.c
@@ -0,0 +1,106 @@
+/* $NetBSD: s_scalbnl.c,v 1.1 2011/07/26 16:10:16 joerg Exp $ */
+
+/*-
+ * Copyright (c) 2011 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Joerg Sonnenberger.
+ *
+ * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+#include <sys/cdefs.h>
+__RCSID("$NetBSD: s_scalbnl.c,v 1.1 2011/07/26 16:10:16 joerg Exp $");
+
+#include "namespace.h"
+
+#include <float.h>
+#include <math.h>
+#include <machine/ieee.h>
+
+#ifdef __HAVE_LONG_DOUBLE
+
+#ifdef __weak_alias
+__weak_alias(scalbnl, _scalbnl)
+#endif
+
+#if LDBL_MANT_DIG == 64
+#define FROM_UNDERFLOW 0x1p65L
+#define TO_UNDERFLOW 0x1p-65L
+#elif LDBL_MANT_DIG == 113
+#define FROM_UNDERFLOW 0x1p114L
+#define TO_UNDERFLOW 0x1p-114L
+#else
+#error Unsupported long double format
+#endif
+
+long double
+scalbnl(long double x, int n)
+{
+ union ieee_ext_u u;
+
+ /* Trivial cases first */
+ if (n == 0 || x == 0.0L)
+ return x;
+
+ u.extu_ld = x;
+
+ /* NaN and infinite don't change either, but trigger exception */
+ if (u.extu_ext.ext_exp == EXT_EXP_INFNAN)
+ return x + x;
+
+ /* Protect against integer overflow in calculation of new exponent */
+ if (n > LDBL_MAX_EXP - LDBL_MIN_EXP + LDBL_MANT_DIG)
+ goto overflow;
+ if (n < LDBL_MAX_EXP - LDBL_MIN_EXP + LDBL_MANT_DIG)
+ goto underflow;
+
+ /* Scale denormalized numbers slightly, so that they are normal */
+ if (u.extu_ext.ext_exp == 0) {
+ u.extu_ld *= FROM_UNDERFLOW;
+ n -= LDBL_MANT_DIG + 1;
+ }
+
+ n += u.extu_ext.ext_exp;
+ if (n >= LDBL_MAX_EXP + EXT_EXP_BIAS)
+ goto overflow;
+ /* Positive exponent (incl. bias) means normal result */
+ if (n > 0) {
+ u.extu_ext.ext_exp = n;
+ return u.extu_ld;
+ }
+ /* Shift the exponent and let the multiply below handle subnormal */
+ n += LDBL_MANT_DIG + 1;
+ if (n <= 0)
+ goto underflow;
+ u.extu_ext.ext_exp = n;
+ return u.extu_ld * TO_UNDERFLOW;
+
+underflow:
+ return LDBL_MIN * copysignl(LDBL_MIN, x);
+
+overflow:
+ return LDBL_MAX * copysignl(LDBL_MAX, x);
+}
+
+#endif