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 #ifndef lint 17 static char rcsid[] = "$FreeBSD$"; 18 #endif 19 20 #include "math.h" 21 #include "math_private.h" 22 23 float 24 nextafterf(float x, float y) 25 { 26 int32_t hx,hy,ix,iy; 27 28 GET_FLOAT_WORD(hx,x); 29 GET_FLOAT_WORD(hy,y); 30 ix = hx&0x7fffffff; /* |x| */ 31 iy = hy&0x7fffffff; /* |y| */ 32 33 if((ix>0x7f800000) || /* x is nan */ 34 (iy>0x7f800000)) /* y is nan */ 35 return x+y; 36 if(x==y) return x; /* x=y, return x */ 37 if(ix==0) { /* x == 0 */ 38 SET_FLOAT_WORD(x,(hy&0x80000000)|1);/* return +-minsubnormal */ 39 y = x*x; 40 if(y==x) return y; else return x; /* raise underflow flag */ 41 } 42 if(hx>=0) { /* x > 0 */ 43 if(hx>hy) { /* x > y, x -= ulp */ 44 hx -= 1; 45 } else { /* x < y, x += ulp */ 46 hx += 1; 47 } 48 } else { /* x < 0 */ 49 if(hy>=0||hx>hy){ /* x < y, x -= ulp */ 50 hx -= 1; 51 } else { /* x > y, x += ulp */ 52 hx += 1; 53 } 54 } 55 hy = hx&0x7f800000; 56 if(hy>=0x7f800000) return x+x; /* overflow */ 57 if(hy<0x00800000) { /* underflow */ 58 y = x*x; 59 if(y!=x) { /* raise underflow flag */ 60 SET_FLOAT_WORD(y,hx); 61 return y; 62 } 63 } 64 SET_FLOAT_WORD(x,hx); 65 return x; 66 } 67