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authorRoland McGrath <roland@gnu.org>1996-03-05 21:41:30 +0000
committerRoland McGrath <roland@gnu.org>1996-03-05 21:41:30 +0000
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parent1521668f2afae1dc2ef5d7ffaeb84353b36874dd (diff)
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Mon Mar 4 20:54:40 1996 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de>
* 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.
Diffstat (limited to 'sysdeps/libm-ieee754/e_remainder.c')
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diff --git a/sysdeps/libm-ieee754/e_remainder.c b/sysdeps/libm-ieee754/e_remainder.c
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+/* @(#)e_remainder.c 5.1 93/09/24 */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: e_remainder.c,v 1.8 1995/05/10 20:46:05 jtc Exp $";
+#endif
+
+/* __ieee754_remainder(x,p)
+ * Return :
+ * returns x REM p = x - [x/p]*p as if in infinite
+ * precise arithmetic, where [x/p] is the (infinite bit)
+ * integer nearest x/p (in half way case choose the even one).
+ * Method :
+ * Based on fmod() return x-[x/p]chopped*p exactlp.
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const double zero = 0.0;
+#else
+static double zero = 0.0;
+#endif
+
+
+#ifdef __STDC__
+ double __ieee754_remainder(double x, double p)
+#else
+ double __ieee754_remainder(x,p)
+ double x,p;
+#endif
+{
+ int32_t hx,hp;
+ u_int32_t sx,lx,lp;
+ double p_half;
+
+ EXTRACT_WORDS(hx,lx,x);
+ EXTRACT_WORDS(hp,lp,p);
+ sx = hx&0x80000000;
+ hp &= 0x7fffffff;
+ hx &= 0x7fffffff;
+
+ /* purge off exception values */
+ if((hp|lp)==0) return (x*p)/(x*p); /* p = 0 */
+ if((hx>=0x7ff00000)|| /* x not finite */
+ ((hp>=0x7ff00000)&& /* p is NaN */
+ (((hp-0x7ff00000)|lp)!=0)))
+ return (x*p)/(x*p);
+
+
+ if (hp<=0x7fdfffff) x = __ieee754_fmod(x,p+p); /* now x < 2p */
+ if (((hx-hp)|(lx-lp))==0) return zero*x;
+ x = fabs(x);
+ p = fabs(p);
+ if (hp<0x00200000) {
+ if(x+x>p) {
+ x-=p;
+ if(x+x>=p) x -= p;
+ }
+ } else {
+ p_half = 0.5*p;
+ if(x>p_half) {
+ x-=p;
+ if(x>=p_half) x -= p;
+ }
+ }
+ GET_HIGH_WORD(hx,x);
+ SET_HIGH_WORD(x,hx^sx);
+ return x;
+}