diff libquadmath/math/nextafterq.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/nextafterq.c	Sun Aug 21 07:07:55 2011 +0900
@@ -0,0 +1,63 @@
+/* s_nextafterl.c -- long double version of s_nextafter.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.
+ * ====================================================
+ */
+
+#include "quadmath-imp.h"
+
+__float128
+nextafterq (__float128 x, __float128 y)
+{
+	int64_t hx,hy,ix,iy;
+	uint64_t lx,ly;
+
+	GET_FLT128_WORDS64(hx,lx,x);
+	GET_FLT128_WORDS64(hy,ly,y);
+	ix = hx&0x7fffffffffffffffLL;		/* |x| */
+	iy = hy&0x7fffffffffffffffLL;		/* |y| */
+
+	if(((ix>=0x7fff000000000000LL)&&((ix-0x7fff000000000000LL)|lx)!=0) ||   /* x is nan */
+	   ((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0))     /* y is nan */
+	   return x+y;
+	if(x==y) return y;		/* x=y, return y */
+	if((ix|lx)==0) {			/* x == 0 */
+	    SET_FLT128_WORDS64(x,hy&0x8000000000000000ULL,1);/* return +-minsubnormal */
+
+	    /* here we should raise an underflow flag */
+	    return x;
+	}
+	if(hx>=0) {			/* x > 0 */
+	    if(hx>hy||((hx==hy)&&(lx>ly))) {	/* x > y, x -= ulp */
+		if(lx==0) hx--;
+		lx--;
+	    } else {				/* x < y, x += ulp */
+		lx++;
+		if(lx==0) hx++;
+	    }
+	} else {				/* x < 0 */
+	    if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
+		if(lx==0) hx--;
+		lx--;
+	    } else {				/* x > y, x += ulp */
+		lx++;
+		if(lx==0) hx++;
+	    }
+	}
+	hy = hx&0x7fff000000000000LL;
+	if(hy==0x7fff000000000000LL) return x+x;/* overflow  */
+	if(hy==0) {
+	    /* here we should raise an underflow flag */
+	}
+	SET_FLT128_WORDS64(x,hx,lx);
+	return x;
+}