84 lines
3.1 KiB
C
84 lines
3.1 KiB
C
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/* $NetBSD: fixunsdfdi.c,v 1.7 2003/08/07 16:43:16 agc Exp $ */
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/*-
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* Copyright (c) 1992, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This software was developed by the Computer Systems Engineering group
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* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
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* contributed to Berkeley.
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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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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* 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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#if 0
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static char sccsid[] = "@(#)fixunsdfdi.c 8.1 (Berkeley) 6/4/93";
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#else
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__RCSID("$NetBSD: fixunsdfdi.c,v 1.7 2003/08/07 16:43:16 agc Exp $");
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#endif
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#endif /* LIBC_SCCS and not lint */
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#include "quad.h"
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#define ONE_FOURTH ((int)1 << (INT_BITS - 2))
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#define ONE_HALF (ONE_FOURTH * 2.0)
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#define ONE (ONE_FOURTH * 4.0)
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/*
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* Convert double to (unsigned) quad.
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* Not sure what to do with negative numbers---for now, anything out
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* of range becomes UQUAD_MAX.
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*/
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u_quad_t
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__fixunsdfdi(x)
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double x;
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{
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union uu t;
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unsigned int tmp;
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if (x < 0)
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return (UQUAD_MAX); /* ??? should be 0? ERANGE??? */
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#ifdef notdef /* this falls afoul of a GCC bug */
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if (x >= UQUAD_MAX)
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return (UQUAD_MAX);
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#else /* so we wire in 2^64-1 instead */
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if (x >= 18446744073709551615.0) /* XXX */
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return (UQUAD_MAX);
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#endif
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/*
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* Now we know that 0 <= x <= 18446744073709549568. The upper
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* limit is one ulp less than 18446744073709551615 tested for above.
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* Dividing this by 2^32 will *not* round irrespective of any
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* rounding modes (except if the result is an IEEE denorm).
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* Furthermore, the quotient will fit into a 32-bit integer.
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*/
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tmp = x / ONE;
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t.ul[L] = (unsigned int) (x - tmp * ONE);
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t.ul[H] = tmp;
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return (t.uq);
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}
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