68 lines
2.3 KiB
C
68 lines
2.3 KiB
C
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/* $NetBSD: floatunsidf_ieee754.c,v 1.1 2013/08/23 16:01:35 matt Exp $ */
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/*-
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* Copyright (c) 2013 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 Matt Thomas of 3am Software Foundry.
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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: floatunsidf_ieee754.c,v 1.1 2013/08/23 16:01:35 matt Exp $");
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#endif /* LIBC_SCCS and not lint */
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#if defined(SOFTFLOAT) || defined(__ARM_EABI__)
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#include "softfloat/softfloat-for-gcc.h"
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#endif
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#include <machine/ieee.h>
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double __floatunsidf(uint32_t);
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/*
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* Convert (unsigned) int to double.
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*/
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double
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__floatunsidf(uint32_t x)
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{
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union ieee_double_u u;
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if (x == 0)
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return 0.0;
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if (x == 1)
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return 1.0;
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u_int l = __builtin_clz(x);
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x <<= (l + 1); /* clear implicit bit */
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u.dblu_sign = 0;
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u.dblu_exp = DBL_EXP_BIAS + 31 - l;
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u.dblu_frach = x >> (32 - DBL_FRACHBITS);
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u.dblu_fracl = x << (32 - DBL_FRACHBITS);
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return u.dblu_d;
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}
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