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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
210 lines
5.3 KiB
C
210 lines
5.3 KiB
C
/*
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* $Id: math_log10.c,v 1.2 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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*
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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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#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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#if defined(IEEE_FLOATING_POINT_SUPPORT)
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/****************************************************************************/
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#if defined(__GNUC__)
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/****************************************************************************/
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#if defined(SMALL_DATA)
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#define A4(x) "a4@(" #x ":W)"
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#elif defined(SMALL_DATA32)
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#define A4(x) "a4@(" #x ":L)"
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#else
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#define A4(x) #x
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#endif /* SMALL_DATA */
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/****************************************************************************/
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extern double __log10(double x);
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/****************************************************************************/
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asm("
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.text
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.even
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.globl _MathIeeeDoubTransBase
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.globl ___log10
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___log10:
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movel a6,sp@-
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movel "A4(_MathIeeeDoubBasBase)",a6
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moveml sp@(8),d0/d1
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jsr a6@(-126:W)
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movel sp@+,a6
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rts
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");
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/****************************************************************************/
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#else
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/****************************************************************************/
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INLINE static const double
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__log10(double x)
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{
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double result;
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result = IEEEDPLog10(x);
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return(result);
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}
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/****************************************************************************/
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#endif /* __GNUC__ */
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/****************************************************************************/
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#endif /* IEEE_FLOATING_POINT_SUPPORT */
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/****************************************************************************/
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#if defined(M68881_FLOATING_POINT_SUPPORT)
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INLINE static const double
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__log10(double x)
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{
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double result;
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__asm ("flog10%.x %1,%0"
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: "=f" (result)
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: "f" (x));
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return(result);
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}
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#endif /* M68881_FLOATING_POINT_SUPPORT */
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/****************************************************************************/
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#if defined(PPC_FLOATING_POINT_SUPPORT)
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static const double
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two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */
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ivln10 = 4.34294481903251816668e-01, /* 0x3FDBCB7B, 0x1526E50E */
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log10_2hi = 3.01029995663611771306e-01, /* 0x3FD34413, 0x509F6000 */
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log10_2lo = 3.69423907715893078616e-13, /* 0x3D59FEF3, 0x11F12B36 */
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zero = 0.0;
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INLINE static const double
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__log10(double x)
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{
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double y,z;
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int i,k,hx;
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unsigned int lx;
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EXTRACT_WORDS(hx,lx,x);
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k=0;
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if (hx < 0x00100000) /* x < 2**-1022 */
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{
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if (((hx&0x7fffffff)|lx)==0)
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return -two54/zero; /* log(+-0)=-inf */
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if (hx<0)
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return (x-x)/zero; /* log(-#) = NaN */
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k -= 54; x *= two54; /* subnormal number, scale up x */
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GET_HIGH_WORD(hx,x);
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}
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if (hx >= 0x7ff00000)
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return x+x;
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k += (hx>>20)-1023;
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i = ((unsigned int)k&0x80000000)>>31;
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hx = (hx&0x000fffff)|((0x3ff-i)<<20);
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y = (double)(k+i);
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SET_HIGH_WORD(x,hx);
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z = y*log10_2lo + ivln10*log(x);
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return z+y*log10_2hi;
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}
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#endif /* PPC_FLOATING_POINT_SUPPORT */
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/****************************************************************************/
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double
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log10(double x)
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{
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double result;
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/* ZZZ when do we consider 'x' to be invalid? If it's close
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* enough to zero or negative. How large is epsilon, and how
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* do we return minus infinity?
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*/
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if(x > 0.0)
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{
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result = __log10(x);
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}
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else
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{
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/* ZZZ this should be minus infinity */
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result = -HUGE_VAL;
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errno = ERANGE;
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}
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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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