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 */
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 #if defined(LIBM_SCCS) && !defined(lint)
17 static char rcsid[] = "$NetBSD: $";
18 #endif
19
20 /* IEEE functions
21 * nextafterq(x,y)
22 * return the next machine floating-point number of x in the
23 * direction toward y.
24 * Special cases:
25 */
26
27 #include "quadmath-imp.h"
28
nextafterq(__float128 x,__float128 y)29 __float128 nextafterq(__float128 x, __float128 y)
30 {
31 int64_t hx,hy,ix,iy;
32 uint64_t lx,ly;
33
34 GET_FLT128_WORDS64(hx,lx,x);
35 GET_FLT128_WORDS64(hy,ly,y);
36 ix = hx&0x7fffffffffffffffLL; /* |x| */
37 iy = hy&0x7fffffffffffffffLL; /* |y| */
38
39 if(((ix>=0x7fff000000000000LL)&&((ix-0x7fff000000000000LL)|lx)!=0) || /* x is nan */
40 ((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0)) /* y is nan */
41 return x+y;
42 if(x==y) return y; /* x=y, return y */
43 if((ix|lx)==0) { /* x == 0 */
44 __float128 u;
45 SET_FLT128_WORDS64(x,hy&0x8000000000000000ULL,1);/* return +-minsubnormal */
46 u = math_opt_barrier (x);
47 u = u * u;
48 math_force_eval (u); /* raise underflow flag */
49 return x;
50 }
51 if(hx>=0) { /* x > 0 */
52 if(hx>hy||((hx==hy)&&(lx>ly))) { /* x > y, x -= ulp */
53 if(lx==0) hx--;
54 lx--;
55 } else { /* x < y, x += ulp */
56 lx++;
57 if(lx==0) hx++;
58 }
59 } else { /* x < 0 */
60 if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
61 if(lx==0) hx--;
62 lx--;
63 } else { /* x > y, x += ulp */
64 lx++;
65 if(lx==0) hx++;
66 }
67 }
68 hy = hx&0x7fff000000000000LL;
69 if(hy==0x7fff000000000000LL) {
70 __float128 u = x + x; /* overflow */
71 math_force_eval (u);
72 errno = ERANGE;
73 }
74 if(hy==0) {
75 __float128 u = x*x; /* underflow */
76 math_force_eval (u); /* raise underflow flag */
77 errno = ERANGE;
78 }
79 SET_FLT128_WORDS64(x,hx,lx);
80 return x;
81 }
82