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- Replaced ISO Latin 1 code #160 with a plain blank space (ASCII code #32) where necessary git-svn-id: file:///Users/olsen/Code/migration-svn-zu-git/logical-line-staging/clib2/trunk@15305 87f5fb63-7c3d-0410-a384-fd976d0f7a62
93 lines
3.2 KiB
C
93 lines
3.2 KiB
C
/*
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* $Id: math_log10f.c,v 1.3 2006-01-08 12:04:23 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) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
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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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*
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* PowerPC math library based in part on work by Sun Microsystems
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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*
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*
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* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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*/
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#ifndef _MATH_HEADERS_H
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#include "math_headers.h"
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#endif /* _MATH_HEADERS_H */
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/****************************************************************************/
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#if defined(FLOATING_POINT_SUPPORT)
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/****************************************************************************/
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static const float
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two25 = 3.3554432000e+07, /* 0x4c000000 */
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ivln10 = 4.3429449201e-01, /* 0x3ede5bd9 */
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log10_2hi = 3.0102920532e-01, /* 0x3e9a2080 */
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log10_2lo = 7.9034151668e-07; /* 0x355427db */
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static const float zero = 0.0;
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float
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log10f(float x)
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{
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float y,z;
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LONG i,k,hx;
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GET_FLOAT_WORD(hx,x);
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k=0;
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if (hx < 0x00800000) { /* x < 2**-126 */
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if ((hx&0x7fffffff)==0)
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return -two25/zero; /* log(+-0)=-inf */
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if (hx<0) return (x-x)/zero; /* log(-#) = NaN */
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k -= 25; x *= two25; /* subnormal number, scale up x */
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GET_FLOAT_WORD(hx,x);
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}
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if (hx >= 0x7f800000) return x+x;
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k += (hx>>23)-127;
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i = ((ULONG)k&0x80000000U)>>31;
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hx = (hx&0x007fffff)|((0x7f-i)<<23);
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y = (float)(k+i);
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SET_FLOAT_WORD(x,hx);
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z = y*log10_2lo + ivln10*logf(x);
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return z+y*log10_2hi;
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}
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/****************************************************************************/
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#endif /* FLOATING_POINT_SUPPORT */
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