0058967bb0
2006-01-31 Richard Guenther <rguenther@suse.de> Paolo Bonzini <bonzini@gnu.org> * Makefile.def (target_modules): Add libgcc-math target module. * configure.in (target_libraries): Add libgcc-math target library. (--enable-libgcc-math): New configure switch. * Makefile.in: Re-generate. * configure: Re-generate. * libgcc-math: New toplevel directory. * doc/install.texi (--disable-libgcc-math): Document. libgcc-math/ * configure.ac: New file. * Makefile.am: Likewise. * configure: New generated file. * Makefile.in: Likewise. * aclocal.m4: Likewise. * libtool-version: New file. * include/ieee754.h: New file. * include/libc-symbols.h: Likewise. * include/math_private.h: Likewise. * i386/Makefile.am: New file. * i386/Makefile.in: New generated file. * i386/sse2.h: New file. * i386/endian.h: Likewise. * i386/sse2.map: Linker script for SSE2 ABI math intrinsics. * flt-32/: Import from glibc. * dbl-64/: Likewise. Co-Authored-By: Paolo Bonzini <bonzini@gnu.org> From-SVN: r110434
73 lines
3.1 KiB
C
73 lines
3.1 KiB
C
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/*
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* IBM Accurate Mathematical Library
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* written by International Business Machines Corp.
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* Copyright (C) 2001 Free Software Foundation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation; either version 2.1 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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/************************************************************************/
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/* */
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/* MODULE_NAME:mplog.c */
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/* */
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/* FUNCTIONS: mplog */
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/* */
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/* FILES NEEDED: endian.h mpa.h mplog.h */
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/* mpexp.c */
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/* */
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/* Multi-Precision logarithm function subroutine (for precision p >= 4, */
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/* 2**(-1024) < x < 2**1024) and x is outside of the interval */
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/* [1-2**(-54),1+2**(-54)]. Upon entry, x should be set to the */
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/* multi-precision value of the input and y should be set into a multi- */
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/* precision value of an approximation of log(x) with relative error */
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/* bound of at most 2**(-52). The routine improves the accuracy of y. */
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/* */
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/************************************************************************/
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#include "endian.h"
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#include "mpa.h"
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void __mpexp(mp_no *, mp_no *, int);
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void __mplog(mp_no *x, mp_no *y, int p) {
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#include "mplog.h"
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int i,m;
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#if 0
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int j,k,m1,m2,n;
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double a,b;
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#endif
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static const int mp[33] = {0,0,0,0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,
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4,4,4,4,4,4,4,4,4,4,4,4,4,4};
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mp_no mpone = {0,{0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
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0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
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0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0}};
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mp_no mpt1,mpt2;
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/* Choose m and initiate mpone */
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m = mp[p]; mpone.e = 1; mpone.d[0]=mpone.d[1]=ONE;
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/* Perform m newton iterations to solve for y: exp(y)-x=0. */
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/* The iterations formula is: y(n+1)=y(n)+(x*exp(-y(n))-1). */
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__cpy(y,&mpt1,p);
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for (i=0; i<m; i++) {
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mpt1.d[0]=-mpt1.d[0];
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__mpexp(&mpt1,&mpt2,p);
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__mul(x,&mpt2,&mpt1,p);
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__sub(&mpt1,&mpone,&mpt2,p);
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__add(y,&mpt2,&mpt1,p);
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__cpy(&mpt1,y,p);
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}
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return;
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}
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