1 files changed, 80 insertions, 0 deletions
diff --git a/libm/e_remainder.c b/libm/e_remainder.c
new file mode 100644
index 000000000..641808118
--- /dev/null
+++ b/libm/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;
+}