1 /* modfq.c -- __float128 version of s_modf.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 static const __float128 one = 1.0;
19
20 __float128
modfq(__float128 x,__float128 * iptr)21 modfq (__float128 x, __float128 *iptr)
22 {
23 int64_t i0,i1,j0;
24 uint64_t i;
25 GET_FLT128_WORDS64(i0,i1,x);
26 j0 = ((i0>>48)&0x7fff)-0x3fff; /* exponent of x */
27 if(j0<48) { /* integer part in high x */
28 if(j0<0) { /* |x|<1 */
29 /* *iptr = +-0 */
30 SET_FLT128_WORDS64(*iptr,i0&0x8000000000000000ULL,0);
31 return x;
32 } else {
33 i = (0x0000ffffffffffffLL)>>j0;
34 if(((i0&i)|i1)==0) { /* x is integral */
35 *iptr = x;
36 /* return +-0 */
37 SET_FLT128_WORDS64(x,i0&0x8000000000000000ULL,0);
38 return x;
39 } else {
40 SET_FLT128_WORDS64(*iptr,i0&(~i),0);
41 return x - *iptr;
42 }
43 }
44 } else if (j0>111) { /* no fraction part */
45 *iptr = x*one;
46 /* We must handle NaNs separately. */
47 if (j0 == 0x4000 && ((i0 & 0x0000ffffffffffffLL) | i1))
48 return x*one;
49 /* return +-0 */
50 SET_FLT128_WORDS64(x,i0&0x8000000000000000ULL,0);
51 return x;
52 } else { /* fraction part in low x */
53 i = -1ULL>>(j0-48);
54 if((i1&i)==0) { /* x is integral */
55 *iptr = x;
56 /* return +-0 */
57 SET_FLT128_WORDS64(x,i0&0x8000000000000000ULL,0);
58 return x;
59 } else {
60 SET_FLT128_WORDS64(*iptr,i0,i1&(~i));
61 return x - *iptr;
62 }
63 }
64 }
65