set default newlib dir's structure

git-svn-id: svn://kolibrios.org@4874 a494cfbc-eb01-0410-851d-a64ba20cac60

contrib/sdk/sources/newlib/libc/math/s_nextafter.c

@@ -0,0 +1,121 @@
+
+/* @(#)s_nextafter.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.
+ * ====================================================
+ */
+
+/*
+FUNCTION
+       <<nextafter>>, <<nextafterf>>---get next number
+
+INDEX
+	nextafter
+INDEX
+	nextafterf
+
+ANSI_SYNOPSIS
+       #include <math.h>
+       double nextafter(double <[val]>, double <[dir]>);
+       float nextafterf(float <[val]>, float <[dir]>);
+
+TRAD_SYNOPSIS
+       #include <math.h>
+
+       double nextafter(<[val]>, <[dir]>)
+              double <[val]>;
+              double <[exp]>;
+
+       float nextafter(<[val]>, <[dir]>)
+              float <[val]>;
+              float <[dir]>;
+
+
+DESCRIPTION
+<<nextafter>> returns the double-precision floating-point number
+closest to <[val]> in the direction toward <[dir]>.  <<nextafterf>>
+performs the same operation in single precision.  For example,
+<<nextafter(0.0,1.0)>> returns the smallest positive number which is
+representable in double precision.
+
+RETURNS
+Returns the next closest number to <[val]> in the direction toward
+<[dir]>.
+
+PORTABILITY
+	Neither <<nextafter>> nor <<nextafterf>> is required by ANSI C
+	or by the System V Interface Definition (Issue 2).
+*/
+
+/* IEEE functions
+ *	nextafter(x,y)
+ *	return the next machine floating-point number of x in the
+ *	direction toward y.
+ *   Special cases:
+ */
+
+#include "fdlibm.h"
+
+#ifndef _DOUBLE_IS_32BITS
+
+#ifdef __STDC__
+	double nextafter(double x, double y)
+#else
+	double nextafter(x,y)
+	double x,y;
+#endif
+{
+	__int32_t	hx,hy,ix,iy;
+	__uint32_t lx,ly;
+
+	EXTRACT_WORDS(hx,lx,x);
+	EXTRACT_WORDS(hy,ly,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 */
+	    INSERT_WORDS(x,hy&0x80000000,1);	/* return +-minsubnormal */
+	    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 */
+	        INSERT_WORDS(y,hx,lx);
+		return y;
+	    }
+	}
+	INSERT_WORDS(x,hx,lx);
+	return x;
+}
+
+#endif /* _DOUBLE_IS_32BITS */