1/* s_nextafterl.c -- long double version of s_nextafter.c. 2 * Special version for i387. 3 * Conversion to long double by Ulrich Drepper, 4 * Cygnus Support, drepper@cygnus.com. 5 */ 6 7/* 8 * ==================================================== 9 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 10 * 11 * Developed at SunPro, a Sun Microsystems, Inc. business. 12 * Permission to use, copy, modify, and distribute this 13 * software is freely granted, provided that this notice 14 * is preserved. 15 * ==================================================== 16 */ 17 18#if defined(LIBM_SCCS) && !defined(lint) 19static char rcsid[] = "$NetBSD: $"; 20#endif 21 22/* IEEE functions 23 * nextafterl(x,y) 24 * return the next machine floating-point number of x in the 25 * direction toward y. 26 * Special cases: 27 */ 28 29#include "math.h" 30#include "math_private.h" 31 32#ifdef __STDC__ 33 long double __nextafterl(long double x, long double y) 34#else 35 long double __nextafterl(x,y) 36 long double x,y; 37#endif 38{ 39 u_int32_t hx,hy,ix,iy; 40 u_int32_t lx,ly; 41 int32_t esx,esy; 42 43 GET_LDOUBLE_WORDS(esx,hx,lx,x); 44 GET_LDOUBLE_WORDS(esy,hy,ly,y); 45 ix = esx&0x7fff; /* |x| */ 46 iy = esy&0x7fff; /* |y| */ 47 48 /* Intel's extended format has the normally implicit 1 explicit 49 present. Sigh! */ 50 if(((ix==0x7fff)&&(((hx&0x7fffffff)|lx)!=0)) || /* x is nan */ 51 ((iy==0x7fff)&&(((hy&0x7fffffff)|ly)!=0))) /* y is nan */ 52 return x+y; 53 if(x==y) return y; /* x=y, return y */ 54 if((ix|hx|lx)==0) { /* x == 0 */ 55 SET_LDOUBLE_WORDS(x,esy&0x8000,0,1);/* return +-minsubnormal */ 56 y = x*x; 57 if(y==x) return y; else return x; /* raise underflow flag */ 58 } 59 if(esx>=0) { /* x > 0 */ 60 if(esx>esy||((esx==esy) && (hx>hy||((hx==hy)&&(lx>ly))))) { 61 /* x > y, x -= ulp */ 62 if(lx==0) { 63 if (hx <= 0x80000000) { 64 if (esx == 0) { 65 --hx; 66 } else { 67 esx -= 1; 68 hx = hx - 1; 69 if (esx > 0) 70 hx |= 0x80000000; 71 } 72 } else 73 hx -= 1; 74 } 75 lx -= 1; 76 } else { /* x < y, x += ulp */ 77 lx += 1; 78 if(lx==0) { 79 hx += 1; 80 if (hx==0 || (esx == 0 && hx == 0x80000000)) { 81 esx += 1; 82 hx |= 0x80000000; 83 } 84 } 85 } 86 } else { /* x < 0 */ 87 if(esy>=0||(esx>esy||((esx==esy)&&(hx>hy||((hx==hy)&&(lx>ly)))))){ 88 /* x < y, x -= ulp */ 89 if(lx==0) { 90 if (hx <= 0x80000000) { 91 esx -= 1; 92 hx = hx - 1; 93 if ((esx&0x7fff) > 0) 94 hx |= 0x80000000; 95 } else 96 hx -= 1; 97 } 98 lx -= 1; 99 } else { /* x > y, x += ulp */ 100 lx += 1; 101 if(lx==0) { 102 hx += 1; 103 if (hx==0 || (esx == 0xffff8000 && hx == 0x80000000)) { 104 esx += 1; 105 hx |= 0x80000000; 106 } 107 } 108 } 109 } 110 esy = esx&0x7fff; 111 if(esy==0x7fff) return x+x; /* overflow */ 112 if(esy==0) { /* underflow */ 113 y = x*x; 114 if(y!=x) { /* raise underflow flag */ 115 SET_LDOUBLE_WORDS(y,esx,hx,lx); 116 return y; 117 } 118 } 119 SET_LDOUBLE_WORDS(x,esx,hx,lx); 120 return x; 121} 122weak_alias (__nextafterl, nextafterl) 123strong_alias (__nextafterl, __nexttowardl) 124weak_alias (__nextafterl, nexttowardl) 125