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 <sys/cdefs.h> 17 #if defined(LIBM_SCCS) && !defined(lint) 18 __RCSID("$NetBSD: s_nextafterf.c,v 1.5 1997/10/09 11:33:08 lukem Exp $"); 19 #endif 20 21 #include "math.h" 22 #include "math_private.h" 23 24 #ifdef __STDC__ 25 float nextafterf(float x, float y) 26 #else 27 float nextafterf(x,y) 28 float x,y; 29 #endif 30 { 31 int32_t hx,hy,ix,iy; 32 33 GET_FLOAT_WORD(hx,x); 34 GET_FLOAT_WORD(hy,y); 35 ix = hx&0x7fffffff; /* |x| */ 36 iy = hy&0x7fffffff; /* |y| */ 37 38 if((ix>0x7f800000) || /* x is nan */ 39 (iy>0x7f800000)) /* y is nan */ 40 return x+y; 41 if(x==y) return x; /* x=y, return x */ 42 if(ix==0) { /* x == 0 */ 43 SET_FLOAT_WORD(x,(hy&0x80000000)|1);/* return +-minsubnormal */ 44 y = x*x; 45 if(y==x) return y; else return x; /* raise underflow flag */ 46 } 47 if(hx>=0) { /* x > 0 */ 48 if(hx>hy) { /* x > y, x -= ulp */ 49 hx -= 1; 50 } else { /* x < y, x += ulp */ 51 hx += 1; 52 } 53 } else { /* x < 0 */ 54 if(hy>=0||hx>hy){ /* x < y, x -= ulp */ 55 hx -= 1; 56 } else { /* x > y, x += ulp */ 57 hx += 1; 58 } 59 } 60 hy = hx&0x7f800000; 61 if(hy>=0x7f800000) return x+x; /* overflow */ 62 if(hy<0x00800000) { /* underflow */ 63 y = x*x; 64 if(y!=x) { /* raise underflow flag */ 65 SET_FLOAT_WORD(y,hx); 66 return y; 67 } 68 } 69 SET_FLOAT_WORD(x,hx); 70 return x; 71 } 72