1/* s_nextafterf.c -- float version of s_nextafter.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
4
5/*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 */
15
16#include "math.h"
17#include "math_private.h"
18
19float
20nextafterf(float x, float y)
21{
22	int32_t hx,hy,ix,iy;
23
24	GET_FLOAT_WORD(hx,x);
25	GET_FLOAT_WORD(hy,y);
26	ix = hx&0x7fffffff;		/* |x| */
27	iy = hy&0x7fffffff;		/* |y| */
28
29	if((ix>0x7f800000) ||   /* x is nan */
30	   (iy>0x7f800000))     /* y is nan */
31	   return x+y;
32	if(x==y) return y;		/* x=y, return y */
33	if(ix==0) {				/* x == 0 */
34	    SET_FLOAT_WORD(x,(hy&0x80000000)|1);/* return +-minsubnormal */
35	    y = x*x;
36	    if(y==x) return y; else return x;	/* raise underflow flag */
37	}
38	if(hx>=0) {				/* x > 0 */
39	    if(hx>hy) {				/* x > y, x -= ulp */
40		hx -= 1;
41	    } else {				/* x < y, x += ulp */
42		hx += 1;
43	    }
44	} else {				/* x < 0 */
45	    if(hy>=0||hx>hy){			/* x < y, x -= ulp */
46		hx -= 1;
47	    } else {				/* x > y, x += ulp */
48		hx += 1;
49	    }
50	}
51	hy = hx&0x7f800000;
52	if(hy>=0x7f800000) return x+x;	/* overflow  */
53	if(hy<0x00800000) {		/* underflow */
54	    y = x*x;
55	    if(y!=x) {		/* raise underflow flag */
56	        SET_FLOAT_WORD(y,hx);
57		return y;
58	    }
59	}
60	SET_FLOAT_WORD(x,hx);
61	return x;
62}
63