1 files changed, 78 insertions, 0 deletions
diff --git a/libm/src/s_nextafter.c b/libm/src/s_nextafter.c
new file mode 100644
index 0000000..c530952
--- /dev/null
+++ b/libm/src/s_nextafter.c
@@ -0,0 +1,78 @@
+
+/* @(#)s_nextafter.c 1.3 95/01/18 */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunSoft, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice 
+ * is preserved.
+ * ====================================================
+ */
+
+/* IEEE functions
+ *	nextafter(x,y)
+ *	return the next machine floating-point number of x in the
+ *	direction toward y.
+ *   Special cases:
+ */
+
+#include "fdlibm.h"
+
+#ifdef __STDC__
+	double nextafter(double x, double y)
+#else
+	double nextafter(x,y)
+	double x,y;
+#endif
+{
+	int	hx,hy,ix,iy;
+	unsigned lx,ly;
+
+	hx = __HI(x);		/* high word of x */
+	lx = __LO(x);		/* low  word of x */
+	hy = __HI(y);		/* high word of y */
+	ly = __LO(y);		/* low  word of y */
+	ix = hx&0x7fffffff;		/* |x| */
+	iy = hy&0x7fffffff;		/* |y| */
+
+	if(((ix>=0x7ff00000)&&((ix-0x7ff00000)|lx)!=0) ||   /* x is nan */ 
+	   ((iy>=0x7ff00000)&&((iy-0x7ff00000)|ly)!=0))     /* y is nan */ 
+	   return x+y;				
+	if(x==y) return x;		/* x=y, return x */
+	if((ix|lx)==0) {			/* x == 0 */
+	    __HI(x) = hy&0x80000000;	/* return +-minsubnormal */
+	    __LO(x) = 1;
+	    y = x*x;
+	    if(y==x) return y; else return x;	/* raise underflow flag */
+	} 
+	if(hx>=0) {				/* x > 0 */
+	    if(hx>hy||((hx==hy)&&(lx>ly))) {	/* x > y, x -= ulp */
+		if(lx==0) hx -= 1;
+		lx -= 1;
+	    } else {				/* x < y, x += ulp */
+		lx += 1;
+		if(lx==0) hx += 1;
+	    }
+	} else {				/* x < 0 */
+	    if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
+		if(lx==0) hx -= 1;
+		lx -= 1;
+	    } else {				/* x > y, x += ulp */
+		lx += 1;
+		if(lx==0) hx += 1;
+	    }
+	}
+	hy = hx&0x7ff00000;
+	if(hy>=0x7ff00000) return x+x;	/* overflow  */
+	if(hy<0x00100000) {		/* underflow */
+	    y = x*x;
+	    if(y!=x) {		/* raise underflow flag */
+		__HI(y) = hx; __LO(y) = lx;
+		return y;
+	    }
+	}
+	__HI(x) = hx; __LO(x) = lx;
+	return x;
+}