1 /* 2 * ==================================================== 3 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 4 * 5 * Developed at SunPro, a Sun Microsystems, Inc. business. 6 * Permission to use, copy, modify, and distribute this 7 * software is freely granted, provided that this notice 8 * is preserved. 9 * ==================================================== 10 */ 11 12 #include <sys/cdefs.h> 13 __FBSDID("$FreeBSD$"); 14 15 #include <float.h> 16 17 #include "fpmath.h" 18 #include "math.h" 19 #include "math_private.h" 20 21 #define LDBL_INFNAN_EXP (LDBL_MAX_EXP * 2 - 1) 22 23 float 24 nexttowardf(float x, long double y) 25 { 26 union IEEEl2bits uy; 27 volatile float t; 28 int32_t hx,ix; 29 30 GET_FLOAT_WORD(hx,x); 31 ix = hx&0x7fffffff; /* |x| */ 32 uy.e = y; 33 34 if((ix>0x7f800000) || 35 (uy.bits.exp == LDBL_INFNAN_EXP && 36 ((uy.bits.manh&~LDBL_NBIT)|uy.bits.manl) != 0)) 37 return x+y; /* x or y is nan */ 38 if(x==y) return (float)y; /* x=y, return y */ 39 if(ix==0) { /* x == 0 */ 40 SET_FLOAT_WORD(x,(uy.bits.sign<<31)|1);/* return +-minsubnormal */ 41 t = x*x; 42 if(t==x) return t; else return x; /* raise underflow flag */ 43 } 44 if(hx>=0 ^ x < y) /* x -= ulp */ 45 hx -= 1; 46 else /* x += ulp */ 47 hx += 1; 48 ix = hx&0x7f800000; 49 if(ix>=0x7f800000) return x+x; /* overflow */ 50 if(ix<0x00800000) { /* underflow */ 51 t = x*x; 52 if(t!=x) { /* raise underflow flag */ 53 SET_FLOAT_WORD(x,hx); 54 return x; 55 } 56 } 57 SET_FLOAT_WORD(x,hx); 58 return x; 59 } 60
