diff libquadmath/math/nearbyintq.c @ 68:561a7518be6b

update gcc-4.6
author Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
date Sun, 21 Aug 2011 07:07:55 +0900
parents
children 04ced10e8804
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line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libquadmath/math/nearbyintq.c	Sun Aug 21 07:07:55 2011 +0900
@@ -0,0 +1,98 @@
+/* nearbyintq.c -- __float128 version of s_nearbyint.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.
+ * ====================================================
+ */
+
+/*
+ * nearbyintq(x)
+ * Return x rounded to integral value according to the prevailing
+ * rounding mode.
+ * Method:
+ *	Using floating addition.
+ * Exception:
+ *	Inexact flag raised if x not equal to rintq(x).
+ */
+
+#include "quadmath-imp.h"
+#ifdef HAVE_FENV_H
+# include <fenv.h>
+# if defined HAVE_FEHOLDEXCEPT && defined HAVE_FESETENV
+#   define USE_FENV_H
+# endif
+#endif
+
+static const __float128
+TWO112[2]={
+  5.19229685853482762853049632922009600E+33Q, /* 0x406F000000000000, 0 */
+ -5.19229685853482762853049632922009600E+33Q  /* 0xC06F000000000000, 0 */
+};
+
+__float128
+nearbyintq(__float128 x)
+{
+#ifdef USE_FENV_H
+	fenv_t env;
+#endif
+	int64_t i0,j0,sx;
+	uint64_t i,i1;
+	__float128 w,t;
+	GET_FLT128_WORDS64(i0,i1,x);
+	sx = (((uint64_t)i0)>>63);
+	j0 = ((i0>>48)&0x7fff)-0x3fff;
+	if(j0<48) {
+	    if(j0<0) {
+		if(((i0&0x7fffffffffffffffLL)|i1)==0) return x;
+		i1 |= (i0&0x0000ffffffffffffLL);
+		i0 &= 0xffffe00000000000ULL;
+		i0 |= ((i1|-i1)>>16)&0x0000800000000000LL;
+		SET_FLT128_MSW64(x,i0);
+#ifdef USE_FENV_H
+		feholdexcept (&env);
+#endif
+	        w = TWO112[sx]+x;
+	        t = w-TWO112[sx];
+#ifdef USE_FENV_H
+	        fesetenv (&env);
+#endif
+		GET_FLT128_MSW64(i0,t);
+		SET_FLT128_MSW64(t,(i0&0x7fffffffffffffffLL)|(sx<<63));
+	        return t;
+	    } else {
+		i = (0x0000ffffffffffffLL)>>j0;
+		if(((i0&i)|i1)==0) return x; /* x is integral */
+		i>>=1;
+		if(((i0&i)|i1)!=0) {
+		    if(j0==47) i1 = 0x4000000000000000ULL; else
+		    i0 = (i0&(~i))|((0x0000200000000000LL)>>j0);
+		}
+	    }
+	} else if (j0>111) {
+	    if(j0==0x4000) return x+x;	/* inf or NaN */
+	    else return x;		/* x is integral */
+	} else {
+	    i = -1ULL>>(j0-48);
+	    if((i1&i)==0) return x;	/* x is integral */
+	    i>>=1;
+	    if((i1&i)!=0) i1 = (i1&(~i))|((0x4000000000000000LL)>>(j0-48));
+	}
+	SET_FLT128_WORDS64(x,i0,i1);
+#ifdef USE_FENV_H
+	feholdexcept (&env);
+#endif
+	w = TWO112[sx]+x;
+	t = w-TWO112[sx];
+#ifdef USE_FENV_H	
+	fesetenv (&env);
+#endif
+	return t;
+}