1 /* s_frexpl.c -- long double version of s_frexp.c.
2 */
3
4 /*
5 * ====================================================
6 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
7 *
8 * Developed at SunPro, a Sun Microsystems, Inc. business.
9 * Permission to use, copy, modify, and distribute this
10 * software is freely granted, provided that this notice
11 * is preserved.
12 * ====================================================
13 */
14
15 #if defined(LIBM_SCCS) && !defined(lint)
16 static char rcsid[] = "$NetBSD: $";
17 #endif
18
19 /*
20 * for non-zero x
21 * x = frexpl(arg,&exp);
22 * return a long double fp quantity x such that 0.5 <= |x| <1.0
23 * and the corresponding binary exponent "exp". That is
24 * arg = x*2^exp.
25 * If arg is inf, 0.0, or NaN, then frexpl(arg,&exp) returns arg
26 * with *exp=0.
27 */
28
29 #include <math.h>
30 #include <math_private.h>
31 #include <libm-alias-ldouble.h>
32
33 static const _Float128
34 two114 = L(2.0769187434139310514121985316880384E+34); /* 0x4071000000000000, 0 */
35
__frexpl(_Float128 x,int * eptr)36 _Float128 __frexpl(_Float128 x, int *eptr)
37 {
38 uint64_t hx, lx, ix;
39 GET_LDOUBLE_WORDS64(hx,lx,x);
40 ix = 0x7fffffffffffffffULL&hx;
41 *eptr = 0;
42 if(ix>=0x7fff000000000000ULL||((ix|lx)==0)) return x + x;/* 0,inf,nan */
43 if (ix<0x0001000000000000ULL) { /* subnormal */
44 x *= two114;
45 GET_LDOUBLE_MSW64(hx,x);
46 ix = hx&0x7fffffffffffffffULL;
47 *eptr = -114;
48 }
49 *eptr += (ix>>48)-16382;
50 hx = (hx&0x8000ffffffffffffULL) | 0x3ffe000000000000ULL;
51 SET_LDOUBLE_MSW64(x,hx);
52 return x;
53 }
54 libm_alias_ldouble (__frexp, frexp)
55