[BZ #2510, BZ #2830, BZ #3137, BZ #3313, BZ #3426, BZ #3465, BZ #3480, BZ #3483,...
[glibc.git] / sysdeps / ieee754 / ldbl-128 / s_nextafterl.c
blobd3df66817823486a0d9b1773ed50fcdb5fa74126
1 /* s_nextafterl.c -- long double version of s_nextafter.c.
2 * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
3 */
5 /*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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 * ====================================================
16 #if defined(LIBM_SCCS) && !defined(lint)
17 static char rcsid[] = "$NetBSD: $";
18 #endif
20 /* IEEE functions
21 * nextafterl(x,y)
22 * return the next machine floating-point number of x in the
23 * direction toward y.
24 * Special cases:
27 #include "math.h"
28 #include "math_private.h"
30 #ifdef __STDC__
31 long double __nextafterl(long double x, long double y)
32 #else
33 long double __nextafterl(x,y)
34 long double x,y;
35 #endif
37 int64_t hx,hy,ix,iy;
38 u_int64_t lx,ly;
40 GET_LDOUBLE_WORDS64(hx,lx,x);
41 GET_LDOUBLE_WORDS64(hy,ly,y);
42 ix = hx&0x7fffffffffffffffLL; /* |x| */
43 iy = hy&0x7fffffffffffffffLL; /* |y| */
45 if(((ix>=0x7fff000000000000LL)&&((ix-0x7fff000000000000LL)|lx)!=0) || /* x is nan */
46 ((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0)) /* y is nan */
47 return x+y;
48 if(x==y) return y; /* x=y, return y */
49 if((ix|lx)==0) { /* x == 0 */
50 SET_LDOUBLE_WORDS64(x,hy&0x8000000000000000ULL,1);/* return +-minsubnormal */
51 y = x*x;
52 if(y==x) return y; else return x; /* raise underflow flag */
54 if(hx>=0) { /* x > 0 */
55 if(hx>hy||((hx==hy)&&(lx>ly))) { /* x > y, x -= ulp */
56 if(lx==0) hx--;
57 lx--;
58 } else { /* x < y, x += ulp */
59 lx++;
60 if(lx==0) hx++;
62 } else { /* x < 0 */
63 if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
64 if(lx==0) hx--;
65 lx--;
66 } else { /* x > y, x += ulp */
67 lx++;
68 if(lx==0) hx++;
71 hy = hx&0x7fff000000000000LL;
72 if(hy==0x7fff000000000000LL) return x+x;/* overflow */
73 if(hy==0) { /* underflow */
74 y = x*x;
75 if(y!=x) { /* raise underflow flag */
76 SET_LDOUBLE_WORDS64(y,hx,lx);
77 return y;
80 SET_LDOUBLE_WORDS64(x,hx,lx);
81 return x;
83 weak_alias (__nextafterl, nextafterl)
84 strong_alias (__nextafterl, __nexttowardl)
85 weak_alias (__nextafterl, nexttowardl)