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 #include "math.h" 18 #include "math_private.h" 19 20 float 21 nextafterf(float x, float y) 22 { 23 volatile float t; 24 int32_t hx,hy,ix,iy; 25 26 GET_FLOAT_WORD(hx,x); 27 GET_FLOAT_WORD(hy,y); 28 ix = hx&0x7fffffff; /* |x| */ 29 iy = hy&0x7fffffff; /* |y| */ 30 31 if((ix>0x7f800000) || /* x is nan */ 32 (iy>0x7f800000)) /* y is nan */ 33 return x+y; 34 if(x==y) return y; /* x=y, return y */ 35 if(ix==0) { /* x == 0 */ 36 SET_FLOAT_WORD(x,(hy&0x80000000)|1);/* return +-minsubnormal */ 37 t = x*x; 38 if(t==x) return t; else return x; /* raise underflow flag */ 39 } 40 if(hx>=0) { /* x > 0 */ 41 if(hx>hy) { /* x > y, x -= ulp */ 42 hx -= 1; 43 } else { /* x < y, x += ulp */ 44 hx += 1; 45 } 46 } else { /* x < 0 */ 47 if(hy>=0||hx>hy){ /* x < y, x -= ulp */ 48 hx -= 1; 49 } else { /* x > y, x += ulp */ 50 hx += 1; 51 } 52 } 53 hy = hx&0x7f800000; 54 if(hy>=0x7f800000) return x+x; /* overflow */ 55 if(hy<0x00800000) { /* underflow */ 56 t = x*x; 57 if(t!=x) { /* raise underflow flag */ 58 SET_FLOAT_WORD(y,hx); 59 return y; 60 } 61 } 62 SET_FLOAT_WORD(x,hx); 63 return x; 64 } 65