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git-svn-id: file:///Users/olsen/Code/migration-svn-zu-git/logical-line-staging/clib2/trunk@14789 87f5fb63-7c3d-0410-a384-fd976d0f7a62
112 lines
3.1 KiB
C
Executable File
112 lines
3.1 KiB
C
Executable File
/*
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* $Id: math_isinf.c,v 1.3 2005-01-02 09:07:07 obarthel Exp $
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*
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* :ts=4
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*
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* Portable ISO 'C' (1994) runtime library for the Amiga computer
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* Copyright (c) 2002-2005 by Olaf Barthel <olsen@sourcery.han.de>
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* All rights reserved.
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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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*
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* - 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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*
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* - Neither the name of Olaf Barthel nor the names of contributors
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* may be used to endorse or promote products derived from this
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* software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND 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 COPYRIGHT OWNER OR CONTRIBUTORS BE
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* 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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#ifndef _STDIO_HEADERS_H
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#include "stdio_headers.h"
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#endif /* _STDIO_HEADERS_H */
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/****************************************************************************/
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#if defined (FLOATING_POINT_SUPPORT)
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/****************************************************************************/
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/* The following is not part of the ISO 'C' (1994) standard. */
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/****************************************************************************/
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int
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isinf(double number)
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{
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int is_infinity;
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int result;
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ENTER();
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/* This assumes that a) 'number' is stored in big endian format
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and b) it is stored in IEEE 754 format. */
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if (sizeof(number) == 4) /* single precision */
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{
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union ieee_single x;
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x.value = number;
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/* Exponent = 255 and fraction = 0.0 */
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is_infinity = ((x.raw[0] & 0x7FFFFFFF) == 0x7F800000);
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}
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else if (sizeof(number) == 8) /* double precision */
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{
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union ieee_double x;
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x.value = number;
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/* Exponent = 2047 and fraction = 0.0 */
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is_infinity = (((x.raw[0] & 0x7FFFFFFF) == 0x7FF00000) && (x.raw[1] == 0));
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}
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#if defined(USE_LONG_DOUBLE)
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else if (sizeof(number) == 12) /* extended precision */
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{
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union ieee_long_double x;
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x.value = number;
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/* Exponent = 32767 and fraction = 0.0 */
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is_infinity = (((x.raw[0] & 0x7FFF0000) == 0x7FFF0000) && (x.raw[1] & 0x7FFFFFFF) == 0 && (x.raw[2] == 0));
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}
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#endif /* USE_LONG_DOUBLE */
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else
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{
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/* Can't happen */
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is_infinity = 0;
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}
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if(is_infinity)
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{
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if(number < 0)
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result = -1;
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else
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result = 1;
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}
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else
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{
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result = 0;
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}
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RETURN(result);
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return(result);
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}
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/****************************************************************************/
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#endif /* FLOATING_POINT_SUPPORT */
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