1143218Sdas/* 2143218Sdas * ==================================================== 3143218Sdas * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 4143218Sdas * 5143218Sdas * Developed at SunPro, a Sun Microsystems, Inc. business. 6143218Sdas * Permission to use, copy, modify, and distribute this 7143218Sdas * software is freely granted, provided that this notice 8143218Sdas * is preserved. 9143218Sdas * ==================================================== 10143218Sdas */ 11143218Sdas 12176451Sdas#include <sys/cdefs.h> 13176451Sdas__FBSDID("$FreeBSD: releng/11.0/lib/msun/src/s_nexttowardf.c 218511 2011-02-10 07:38:38Z das $"); 14143218Sdas 15143218Sdas#include <float.h> 16143218Sdas 17143218Sdas#include "fpmath.h" 18143218Sdas#include "math.h" 19143218Sdas#include "math_private.h" 20143218Sdas 21143218Sdas#define LDBL_INFNAN_EXP (LDBL_MAX_EXP * 2 - 1) 22143218Sdas 23143218Sdasfloat 24143218Sdasnexttowardf(float x, long double y) 25143218Sdas{ 26143218Sdas union IEEEl2bits uy; 27143218Sdas volatile float t; 28143218Sdas int32_t hx,ix; 29143218Sdas 30143218Sdas GET_FLOAT_WORD(hx,x); 31143218Sdas ix = hx&0x7fffffff; /* |x| */ 32143218Sdas uy.e = y; 33143218Sdas 34143218Sdas if((ix>0x7f800000) || 35143218Sdas (uy.bits.exp == LDBL_INFNAN_EXP && 36143218Sdas ((uy.bits.manh&~LDBL_NBIT)|uy.bits.manl) != 0)) 37143218Sdas return x+y; /* x or y is nan */ 38143218Sdas if(x==y) return (float)y; /* x=y, return y */ 39143218Sdas if(ix==0) { /* x == 0 */ 40143218Sdas SET_FLOAT_WORD(x,(uy.bits.sign<<31)|1);/* return +-minsubnormal */ 41143218Sdas t = x*x; 42143218Sdas if(t==x) return t; else return x; /* raise underflow flag */ 43143218Sdas } 44143218Sdas if(hx>=0 ^ x < y) /* x -= ulp */ 45143218Sdas hx -= 1; 46143218Sdas else /* x += ulp */ 47143218Sdas hx += 1; 48143218Sdas ix = hx&0x7f800000; 49143218Sdas if(ix>=0x7f800000) return x+x; /* overflow */ 50143218Sdas if(ix<0x00800000) { /* underflow */ 51143218Sdas t = x*x; 52143218Sdas if(t!=x) { /* raise underflow flag */ 53218511Sdas SET_FLOAT_WORD(x,hx); 54218511Sdas return x; 55143218Sdas } 56143218Sdas } 57143218Sdas SET_FLOAT_WORD(x,hx); 58143218Sdas return x; 59143218Sdas} 60