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#if defined(LIBM_SCCS) && !defined(lint)
17static char rcsid[] = "$NetBSD: s_nextafterf.c,v 1.4 1995/05/10 20:48:01 jtc Exp $";
18#endif
19
20#include <errno.h>
21#include <math.h>
22#include <math-barriers.h>
23#include <math_private.h>
24#include <libm-alias-float.h>
25#include <float.h>
26
27float __nextafterf(float x, float y)
28{
29 int32_t hx,hy,ix,iy;
30
31 GET_FLOAT_WORD(hx,x);
32 GET_FLOAT_WORD(hy,y);
33 ix = hx&0x7fffffff; /* |x| */
34 iy = hy&0x7fffffff; /* |y| */
35
36 if((ix>0x7f800000) || /* x is nan */
37 (iy>0x7f800000)) /* y is nan */
38 return x+y;
39 if(x==y) return y; /* x=y, return y */
40 if(ix==0) { /* x == 0 */
41 float u;
42 SET_FLOAT_WORD(x,(hy&0x80000000)|1);/* return +-minsubnormal */
43 u = math_opt_barrier (x);
44 u = u*u;
45 math_force_eval (u); /* raise underflow flag */
46 return x;
47 }
48 if(hx>=0) { /* x > 0 */
49 if(hx>hy) { /* x > y, x -= ulp */
50 hx -= 1;
51 } else { /* x < y, x += ulp */
52 hx += 1;
53 }
54 } else { /* x < 0 */
55 if(hy>=0||hx>hy){ /* x < y, x -= ulp */
56 hx -= 1;
57 } else { /* x > y, x += ulp */
58 hx += 1;
59 }
60 }
61 hy = hx&0x7f800000;
62 if(hy>=0x7f800000) {
63 float u = x+x; /* overflow */
64 math_force_eval (u);
65 __set_errno (ERANGE);
66 }
67 if(hy<0x00800000) {
68 float u = x*x; /* underflow */
69 math_force_eval (u); /* raise underflow flag */
70 __set_errno (ERANGE);
71 }
72 SET_FLOAT_WORD(x,hx);
73 return x;
74}
75libm_alias_float (__nextafter, nextafter)
76