1*627f7eb2Smrg /* s_nextafterl.c -- long double version of s_nextafter.c.
2*627f7eb2Smrg * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
3*627f7eb2Smrg */
4*627f7eb2Smrg
5*627f7eb2Smrg /*
6*627f7eb2Smrg * ====================================================
7*627f7eb2Smrg * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8*627f7eb2Smrg *
9*627f7eb2Smrg * Developed at SunPro, a Sun Microsystems, Inc. business.
10*627f7eb2Smrg * Permission to use, copy, modify, and distribute this
11*627f7eb2Smrg * software is freely granted, provided that this notice
12*627f7eb2Smrg * is preserved.
13*627f7eb2Smrg * ====================================================
14*627f7eb2Smrg */
15*627f7eb2Smrg
16*627f7eb2Smrg #if defined(LIBM_SCCS) && !defined(lint)
17*627f7eb2Smrg static char rcsid[] = "NetBSD: ";
18*627f7eb2Smrg #endif
19*627f7eb2Smrg
20*627f7eb2Smrg /* IEEE functions
21*627f7eb2Smrg * nextafterq(x,y)
22*627f7eb2Smrg * return the next machine floating-point number of x in the
23*627f7eb2Smrg * direction toward y.
24*627f7eb2Smrg * Special cases:
25*627f7eb2Smrg */
26*627f7eb2Smrg
27*627f7eb2Smrg #include "quadmath-imp.h"
28*627f7eb2Smrg
nextafterq(__float128 x,__float128 y)29*627f7eb2Smrg __float128 nextafterq(__float128 x, __float128 y)
30*627f7eb2Smrg {
31*627f7eb2Smrg int64_t hx,hy,ix,iy;
32*627f7eb2Smrg uint64_t lx,ly;
33*627f7eb2Smrg
34*627f7eb2Smrg GET_FLT128_WORDS64(hx,lx,x);
35*627f7eb2Smrg GET_FLT128_WORDS64(hy,ly,y);
36*627f7eb2Smrg ix = hx&0x7fffffffffffffffLL; /* |x| */
37*627f7eb2Smrg iy = hy&0x7fffffffffffffffLL; /* |y| */
38*627f7eb2Smrg
39*627f7eb2Smrg if(((ix>=0x7fff000000000000LL)&&((ix-0x7fff000000000000LL)|lx)!=0) || /* x is nan */
40*627f7eb2Smrg ((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0)) /* y is nan */
41*627f7eb2Smrg return x+y;
42*627f7eb2Smrg if(x==y) return y; /* x=y, return y */
43*627f7eb2Smrg if((ix|lx)==0) { /* x == 0 */
44*627f7eb2Smrg __float128 u;
45*627f7eb2Smrg SET_FLT128_WORDS64(x,hy&0x8000000000000000ULL,1);/* return +-minsubnormal */
46*627f7eb2Smrg u = math_opt_barrier (x);
47*627f7eb2Smrg u = u * u;
48*627f7eb2Smrg math_force_eval (u); /* raise underflow flag */
49*627f7eb2Smrg return x;
50*627f7eb2Smrg }
51*627f7eb2Smrg if(hx>=0) { /* x > 0 */
52*627f7eb2Smrg if(hx>hy||((hx==hy)&&(lx>ly))) { /* x > y, x -= ulp */
53*627f7eb2Smrg if(lx==0) hx--;
54*627f7eb2Smrg lx--;
55*627f7eb2Smrg } else { /* x < y, x += ulp */
56*627f7eb2Smrg lx++;
57*627f7eb2Smrg if(lx==0) hx++;
58*627f7eb2Smrg }
59*627f7eb2Smrg } else { /* x < 0 */
60*627f7eb2Smrg if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
61*627f7eb2Smrg if(lx==0) hx--;
62*627f7eb2Smrg lx--;
63*627f7eb2Smrg } else { /* x > y, x += ulp */
64*627f7eb2Smrg lx++;
65*627f7eb2Smrg if(lx==0) hx++;
66*627f7eb2Smrg }
67*627f7eb2Smrg }
68*627f7eb2Smrg hy = hx&0x7fff000000000000LL;
69*627f7eb2Smrg if(hy==0x7fff000000000000LL) {
70*627f7eb2Smrg __float128 u = x + x; /* overflow */
71*627f7eb2Smrg math_force_eval (u);
72*627f7eb2Smrg errno = ERANGE;
73*627f7eb2Smrg }
74*627f7eb2Smrg if(hy==0) {
75*627f7eb2Smrg __float128 u = x*x; /* underflow */
76*627f7eb2Smrg math_force_eval (u); /* raise underflow flag */
77*627f7eb2Smrg errno = ERANGE;
78*627f7eb2Smrg }
79*627f7eb2Smrg SET_FLT128_WORDS64(x,hx,lx);
80*627f7eb2Smrg return x;
81*627f7eb2Smrg }
82