f7eac6eb50
* Makeconfig ($(common-objpfx)config.make): Depend on config.h.in. Mon Mar 4 17:35:09 1996 Roland McGrath <roland@charlie-brown.gnu.ai.mit.edu> * hurd/catch-signal.c (hurd_safe_memmove): New function. (hurd_safe_copyin, hurd_safe_copyout): New functions. * hurd/hurd/sigpreempt.h: Declare them. Sun Mar 3 08:43:44 1996 Roland McGrath <roland@charlie-brown.gnu.ai.mit.edu> Replace math code with fdlibm from Sun as modified for netbsd by JT Conklin and Ian Taylor, including x86 FPU support. * sysdeps/libm-ieee754, sysdeps/libm-i387: New directories. * math/math_private.h: New file. * sysdeps/i386/fpu/Implies: New file. * sysdeps/ieee754/Implies: New file. * math/machine/asm.h, math/machine/endian.h: New files. * math/Makefile, math/math.h: Rewritten. * mathcalls.h, math/mathcalls.h: New file, broken out of math.h. * math/finite.c: File removed. * sysdeps/generic/Makefile [$(subdir)=math]: Frobnication removed. * math/test-math.c: Include errno.h and string.h. * sysdeps/unix/bsd/dirstream.h: File removed. * sysdeps/unix/bsd/readdir.c: File removed.
81 lines
1.8 KiB
C
81 lines
1.8 KiB
C
/* @(#)e_remainder.c 5.1 93/09/24 */
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/*
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* ====================================================
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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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#if defined(LIBM_SCCS) && !defined(lint)
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static char rcsid[] = "$NetBSD: e_remainder.c,v 1.8 1995/05/10 20:46:05 jtc Exp $";
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#endif
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/* __ieee754_remainder(x,p)
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* Return :
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* returns x REM p = x - [x/p]*p as if in infinite
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* precise arithmetic, where [x/p] is the (infinite bit)
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* integer nearest x/p (in half way case choose the even one).
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* Method :
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* Based on fmod() return x-[x/p]chopped*p exactlp.
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*/
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#include "math.h"
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#include "math_private.h"
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#ifdef __STDC__
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static const double zero = 0.0;
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#else
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static double zero = 0.0;
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#endif
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#ifdef __STDC__
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double __ieee754_remainder(double x, double p)
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#else
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double __ieee754_remainder(x,p)
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double x,p;
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#endif
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{
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int32_t hx,hp;
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u_int32_t sx,lx,lp;
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double p_half;
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EXTRACT_WORDS(hx,lx,x);
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EXTRACT_WORDS(hp,lp,p);
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sx = hx&0x80000000;
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hp &= 0x7fffffff;
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hx &= 0x7fffffff;
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/* purge off exception values */
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if((hp|lp)==0) return (x*p)/(x*p); /* p = 0 */
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if((hx>=0x7ff00000)|| /* x not finite */
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((hp>=0x7ff00000)&& /* p is NaN */
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(((hp-0x7ff00000)|lp)!=0)))
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return (x*p)/(x*p);
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if (hp<=0x7fdfffff) x = __ieee754_fmod(x,p+p); /* now x < 2p */
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if (((hx-hp)|(lx-lp))==0) return zero*x;
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x = fabs(x);
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p = fabs(p);
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if (hp<0x00200000) {
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if(x+x>p) {
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x-=p;
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if(x+x>=p) x -= p;
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}
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} else {
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p_half = 0.5*p;
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if(x>p_half) {
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x-=p;
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if(x>=p_half) x -= p;
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}
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}
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GET_HIGH_WORD(hx,x);
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SET_HIGH_WORD(x,hx^sx);
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return x;
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}
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