1*05a0b428SJohn Marino /* s_nextafterf.c -- float version of s_nextafter.c.
2*05a0b428SJohn Marino * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3*05a0b428SJohn Marino */
4*05a0b428SJohn Marino
5*05a0b428SJohn Marino /*
6*05a0b428SJohn Marino * ====================================================
7*05a0b428SJohn Marino * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8*05a0b428SJohn Marino *
9*05a0b428SJohn Marino * Developed at SunPro, a Sun Microsystems, Inc. business.
10*05a0b428SJohn Marino * Permission to use, copy, modify, and distribute this
11*05a0b428SJohn Marino * software is freely granted, provided that this notice
12*05a0b428SJohn Marino * is preserved.
13*05a0b428SJohn Marino * ====================================================
14*05a0b428SJohn Marino */
15*05a0b428SJohn Marino
16*05a0b428SJohn Marino #include "math.h"
17*05a0b428SJohn Marino #include "math_private.h"
18*05a0b428SJohn Marino
19*05a0b428SJohn Marino float
nextafterf(float x,float y)20*05a0b428SJohn Marino nextafterf(float x, float y)
21*05a0b428SJohn Marino {
22*05a0b428SJohn Marino int32_t hx,hy,ix,iy;
23*05a0b428SJohn Marino
24*05a0b428SJohn Marino GET_FLOAT_WORD(hx,x);
25*05a0b428SJohn Marino GET_FLOAT_WORD(hy,y);
26*05a0b428SJohn Marino ix = hx&0x7fffffff; /* |x| */
27*05a0b428SJohn Marino iy = hy&0x7fffffff; /* |y| */
28*05a0b428SJohn Marino
29*05a0b428SJohn Marino if((ix>0x7f800000) || /* x is nan */
30*05a0b428SJohn Marino (iy>0x7f800000)) /* y is nan */
31*05a0b428SJohn Marino return x+y;
32*05a0b428SJohn Marino if(x==y) return y; /* x=y, return y */
33*05a0b428SJohn Marino if(ix==0) { /* x == 0 */
34*05a0b428SJohn Marino SET_FLOAT_WORD(x,(hy&0x80000000)|1);/* return +-minsubnormal */
35*05a0b428SJohn Marino y = x*x;
36*05a0b428SJohn Marino if(y==x) return y; else return x; /* raise underflow flag */
37*05a0b428SJohn Marino }
38*05a0b428SJohn Marino if(hx>=0) { /* x > 0 */
39*05a0b428SJohn Marino if(hx>hy) { /* x > y, x -= ulp */
40*05a0b428SJohn Marino hx -= 1;
41*05a0b428SJohn Marino } else { /* x < y, x += ulp */
42*05a0b428SJohn Marino hx += 1;
43*05a0b428SJohn Marino }
44*05a0b428SJohn Marino } else { /* x < 0 */
45*05a0b428SJohn Marino if(hy>=0||hx>hy){ /* x < y, x -= ulp */
46*05a0b428SJohn Marino hx -= 1;
47*05a0b428SJohn Marino } else { /* x > y, x += ulp */
48*05a0b428SJohn Marino hx += 1;
49*05a0b428SJohn Marino }
50*05a0b428SJohn Marino }
51*05a0b428SJohn Marino hy = hx&0x7f800000;
52*05a0b428SJohn Marino if(hy>=0x7f800000) return x+x; /* overflow */
53*05a0b428SJohn Marino if(hy<0x00800000) { /* underflow */
54*05a0b428SJohn Marino y = x*x;
55*05a0b428SJohn Marino if(y!=x) { /* raise underflow flag */
56*05a0b428SJohn Marino SET_FLOAT_WORD(y,hx);
57*05a0b428SJohn Marino return y;
58*05a0b428SJohn Marino }
59*05a0b428SJohn Marino }
60*05a0b428SJohn Marino SET_FLOAT_WORD(x,hx);
61*05a0b428SJohn Marino return x;
62*05a0b428SJohn Marino }
63