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