1/* nextafterq.c -- __float128 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#include <errno.h>
17#include "quadmath-imp.h"
18
19__float128
20nextafterq (__float128 x, __float128 y)
21{
22 int64_t hx,hy,ix,iy;
23 uint64_t lx,ly;
24
25 GET_FLT128_WORDS64(hx,lx,x);
26 GET_FLT128_WORDS64(hy,ly,y);
27 ix = hx&0x7fffffffffffffffLL; /* |x| */
28 iy = hy&0x7fffffffffffffffLL; /* |y| */
29
30 if(((ix>=0x7fff000000000000LL)&&((ix-0x7fff000000000000LL)|lx)!=0) || /* x is nan */
31 ((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0)) /* y is nan */
32 return x+y;
33 if(x==y) return y; /* x=y, return y */
34 if((ix|lx)==0) { /* x == 0 */
35 SET_FLT128_WORDS64(x,hy&0x8000000000000000ULL,1);/* return +-minsubnormal */
36
37 /* here we should raise an underflow flag */
38 return x;
39 }
40 if(hx>=0) { /* x > 0 */
41 if(hx>hy||((hx==hy)&&(lx>ly))) { /* x > y, x -= ulp */
42 if(lx==0) hx--;
43 lx--;
44 } else { /* x < y, x += ulp */
45 lx++;
46 if(lx==0) hx++;
47 }
48 } else { /* x < 0 */
49 if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
50 if(lx==0) hx--;
51 lx--;
52 } else { /* x > y, x += ulp */
53 lx++;
54 if(lx==0) hx++;
55 }
56 }
57 hy = hx&0x7fff000000000000LL;
58 if(hy==0x7fff000000000000LL) {
59 __float128 u = x + x; /* overflow */
60 math_force_eval (u);
61 errno = ERANGE;
62 }
63 if(hy==0) {
64 __float128 u = x*x; /* underflow */
65 math_force_eval (u); /* raise underflow flag */
66 errno = ERANGE;
67 }
68 SET_FLT128_WORDS64(x,hx,lx);
69 return x;
70}
71