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539cc3553d
islessequal() and islessgreater() to <math.h> for C99. - The wchar_t type is now an 'unsigned short' integer (16 bits wide). - Added PTRDIFF_MIN/PTRDIFF_MAX, WCHAR_MIN/WCHAR_MAX and WINT_MIN/WINT_MAX to <stdint.h> for C99. - Added imaxdiv() and imaxabs() for C99. - Added strtoimax() and strtoumax() for C99. - Added nextafter() and nextafterf() for C99. - Added copysign() and copysignf() for C99. - Unless I missed something, clib2 should now be functionally complete with regard to C99, except for the floating point operations covered. These are a major challenge all by themselves, and I wonder both whether they are worth the effort and how one could implement them correctly. - fflush() now consistently supports a NULL parameter, causing all streams to be flushed for which this behaviour is defined. git-svn-id: file:///Users/olsen/Code/migration-svn-zu-git/logical-line-staging/clib2/trunk@14943 87f5fb63-7c3d-0410-a384-fd976d0f7a62
106 lines
3.4 KiB
C
106 lines
3.4 KiB
C
/*
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* $Id: math_nextafter.c,v 1.1 2005-05-12 13:21:43 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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double
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nextafter(double x,double y)
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{
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long hx,hy,ix,iy;
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unsigned long lx,ly;
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EXTRACT_WORDS(hx,lx,x);
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EXTRACT_WORDS(hy,ly,y);
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ix = hx&0x7fffffff; /* |x| */
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iy = hy&0x7fffffff; /* |y| */
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if(((ix>=0x7ff00000)&&((ix-0x7ff00000)|lx)!=0) || /* x is nan */
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((iy>=0x7ff00000)&&((iy-0x7ff00000)|ly)!=0)) /* y is nan */
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return x+y;
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if(x==y) return x; /* x=y, return x */
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if((ix|lx)==0) { /* x == 0 */
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INSERT_WORDS(x,hy&0x80000000U,1); /* return +-minsubnormal */
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y = x*x;
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if(y==x) return y; else return x; /* raise underflow flag */
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}
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if(hx>=0) { /* x > 0 */
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if(hx>hy||((hx==hy)&&(lx>ly))) { /* x > y, x -= ulp */
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if(lx==0) hx -= 1;
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lx -= 1;
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} else { /* x < y, x += ulp */
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lx += 1;
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if(lx==0) hx += 1;
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}
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} else { /* x < 0 */
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if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
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if(lx==0) hx -= 1;
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lx -= 1;
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} else { /* x > y, x += ulp */
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lx += 1;
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if(lx==0) hx += 1;
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}
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}
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hy = hx&0x7ff00000;
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if(hy>=0x7ff00000) return x+x; /* overflow */
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if(hy<0x00100000) { /* underflow */
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y = x*x;
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if(y!=x) { /* raise underflow flag */
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INSERT_WORDS(y,hx,lx);
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return y;
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}
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}
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INSERT_WORDS(x,hx,lx);
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return x;
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}
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/****************************************************************************/
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#endif /* FLOATING_POINT_SUPPORT */
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