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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
commitf7eac6eb504f4baf13dbb4d26717942df050ebe6 (patch)
tree95ff129c06c7f6f246a5e2bfa489ba6382659d19 /sysdeps/libm-ieee754/e_remainder.c
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')
-rw-r--r--sysdeps/libm-ieee754/e_remainder.c80
1 files changed, 80 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/e_remainder.c b/sysdeps/libm-ieee754/e_remainder.c
new file mode 100644
index 0000000000..6418081182
--- /dev/null
+++ b/sysdeps/libm-ieee754/e_remainder.c
@@ -0,0 +1,80 @@
+/* @(#)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;
+}