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authorUlrich Drepper <drepper@redhat.com>1999-07-14 00:54:57 +0000
committerUlrich Drepper <drepper@redhat.com>1999-07-14 00:54:57 +0000
commitabfbdde177c3a7155070dda1b2cdc8292054cc26 (patch)
treee021306b596381fbf8311d2b7eb294e918ff17c8 /sysdeps/ieee754/ldbl-128/e_remainderl.c
parent86421aa57ecfd70963ae66848bd6a6dd3b8e0fe6 (diff)
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Update.
Diffstat (limited to 'sysdeps/ieee754/ldbl-128/e_remainderl.c')
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diff --git a/sysdeps/ieee754/ldbl-128/e_remainderl.c b/sysdeps/ieee754/ldbl-128/e_remainderl.c
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+/* e_fmodl.c -- long double version of e_fmod.c.
+ * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
+ */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+/* __ieee754_remainderl(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 fmodl() return x-[x/p]chopped*p exactlp.
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const long double zero = 0.0L;
+#else
+static long double zero = 0.0L;
+#endif
+
+
+#ifdef __STDC__
+	long double __ieee754_remainderl(long double x, long double p)
+#else
+	long double __ieee754_remainderl(x,p)
+	long double x,p;
+#endif
+{
+	int64_t hx,hp;
+	u_int64_t sx,lx,lp;
+	long double p_half;
+
+	GET_LDOUBLE_WORDS64(hx,lx,x);
+	GET_LDOUBLE_WORDS64(hp,lp,p);
+	sx = hx&0x8000000000000000ULL;
+	hp &= 0x7fffffffffffffffLL;
+	hx &= 0x7fffffffffffffffLL;
+
+    /* purge off exception values */
+	if((hp|lp)==0) return (x*p)/(x*p); 	/* p = 0 */
+	if((hx>=0x7fff000000000000LL)||			/* x not finite */
+	  ((hp>=0x7fff000000000000LL)&&			/* p is NaN */
+	  (((hp-0x7fff000000000000LL)|lp)!=0)))
+	    return (x*p)/(x*p);
+
+
+	if (hp<=0x7ffdffffffffffffLL) x = __ieee754_fmodl(x,p+p);	/* now x < 2p */
+	if (((hx-hp)|(lx-lp))==0) return zero*x;
+	x  = fabsl(x);
+	p  = fabsl(p);
+	if (hp<0x0002000000000000LL) {
+	    if(x+x>p) {
+		x-=p;
+		if(x+x>=p) x -= p;
+	    }
+	} else {
+	    p_half = 0.5L*p;
+	    if(x>p_half) {
+		x-=p;
+		if(x>=p_half) x -= p;
+	    }
+	}
+	GET_LDOUBLE_MSW64(hx,x);
+	SET_LDOUBLE_MSW64(x,hx^sx);
+	return x;
+}