There is important information about booting non-ack images in docs/UPDATING. ack/aout-format images can't be built any more, and booting clang/ELF-format ones is a little different. Updating to the new boot monitor is recommended. Changes in this commit: . drop boot monitor -> allowing dropping ack support . facility to copy ELF boot files to /boot so that old boot monitor can still boot fairly easily, see UPDATING . no more ack-format libraries -> single-case libraries . some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases . drop several ack toolchain commands, but not all support commands (e.g. aal is gone but acksize is not yet). . a few libc files moved to netbsd libc dir . new /bin/date as minix date used code in libc/ . test compile fix . harmonize includes . /usr/lib is no longer special: without ack, /usr/lib plays no kind of special bootstrapping role any more and bootstrapping is done exclusively through packages, so releases depend even less on the state of the machine making them now. . rename nbsd_lib* to lib* . reduce mtree
142 lines
4.2 KiB
C
142 lines
4.2 KiB
C
/* $NetBSD: ldexp_ieee754.c,v 1.5 2008/04/28 20:22:59 martin Exp $ */
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/*-
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* Copyright (c) 1999 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Charles M. Hannum.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#if defined(LIBC_SCCS) && !defined(lint)
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__RCSID("$NetBSD: ldexp_ieee754.c,v 1.5 2008/04/28 20:22:59 martin Exp $");
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#endif /* LIBC_SCCS and not lint */
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#include <sys/types.h>
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#include <machine/ieee.h>
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#include <errno.h>
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#include <math.h>
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/*
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* Multiply the given value by 2^expon.
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*/
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double
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ldexp(double val, int expon)
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{
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int oldexp, newexp;
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union ieee_double_u u, mul;
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u.dblu_d = val;
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oldexp = u.dblu_dbl.dbl_exp;
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/*
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* If input is zero, Inf or NaN, just return it.
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*/
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if (u.dblu_d == 0.0 || oldexp == DBL_EXP_INFNAN)
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return (val);
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if (oldexp == 0) {
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/*
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* u.v is denormal. We must adjust it so that the exponent
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* arithmetic below will work.
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*/
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if (expon <= DBL_EXP_BIAS) {
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/*
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* Optimization: if the scaling can be done in a single
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* multiply, or underflows, just do it now.
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*/
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if (expon <= -DBL_FRACBITS) {
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errno = ERANGE;
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return (val < 0.0 ? -0.0 : 0.0);
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}
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mul.dblu_d = 0.0;
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mul.dblu_dbl.dbl_exp = expon + DBL_EXP_BIAS;
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u.dblu_d *= mul.dblu_d;
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if (u.dblu_d == 0.0) {
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errno = ERANGE;
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return (val < 0.0 ? -0.0 : 0.0);
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}
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return (u.dblu_d);
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} else {
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/*
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* We know that expon is very large, and therefore the
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* result cannot be denormal (though it may be Inf).
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* Shift u.v by just enough to make it normal.
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*/
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mul.dblu_d = 0.0;
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mul.dblu_dbl.dbl_exp = DBL_FRACBITS + DBL_EXP_BIAS;
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u.dblu_d *= mul.dblu_d;
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expon -= DBL_FRACBITS;
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oldexp = u.dblu_dbl.dbl_exp;
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}
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}
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/*
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* u.v is now normalized and oldexp has been adjusted if necessary.
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* Calculate the new exponent and check for underflow and overflow.
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*/
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newexp = oldexp + expon;
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if (newexp <= 0) {
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/*
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* The output number is either denormal or underflows (see
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* comments in machine/ieee.h).
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*/
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if (newexp <= -DBL_FRACBITS) {
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errno = ERANGE;
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return (val < 0.0 ? -0.0 : 0.0);
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}
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/*
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* Denormalize the result. We do this with a multiply. If
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* expon is very large, it won't fit in a double, so we have
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* to adjust the exponent first. This is safe because we know
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* that u.v is normal at this point.
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*/
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if (expon <= -DBL_EXP_BIAS) {
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u.dblu_dbl.dbl_exp = 1;
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expon += oldexp - 1;
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}
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mul.dblu_d = 0.0;
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mul.dblu_dbl.dbl_exp = expon + DBL_EXP_BIAS;
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u.dblu_d *= mul.dblu_d;
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return (u.dblu_d);
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} else if (newexp >= DBL_EXP_INFNAN) {
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/*
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* The result overflowed; return +/-Inf.
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*/
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u.dblu_dbl.dbl_exp = DBL_EXP_INFNAN;
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u.dblu_dbl.dbl_frach = 0;
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u.dblu_dbl.dbl_fracl = 0;
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errno = ERANGE;
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return (u.dblu_d);
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} else {
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/*
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* The result is normal; just replace the old exponent with the
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* new one.
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*/
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u.dblu_dbl.dbl_exp = newexp;
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return (u.dblu_d);
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}
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}
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