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
18static const __float128 one = 1.0;
19
20__float128
21modfq (__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