diff options
| author | joerg <joerg@NetBSD.org> | 2011-07-26 16:10:15 +0000 |
|---|---|---|
| committer | joerg <joerg@NetBSD.org> | 2011-07-26 16:10:15 +0000 |
| commit | f363aaa8561cd43a8f7ceafe0a31bfc2b5740545 (patch) | |
| tree | af2788e152e53b28cd5a5c71524d1240d0317728 /lib/libm/src | |
| parent | c8fc07cf75ebd25d6811851404585a9c6ce0d99f (diff) | |
Add scalbnl to libm.
Diffstat (limited to 'lib/libm/src')
| -rw-r--r-- | lib/libm/src/namespace.h | 3 | ||||
| -rw-r--r-- | lib/libm/src/s_scalbn.c | 7 | ||||
| -rw-r--r-- | lib/libm/src/s_scalbnl.c | 106 |
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 |
