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