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 <float.h>
30 #include <math.h>
31 #include <math_private.h>
32 #include <libm-alias-ldouble.h>
33
34 static const long double
35 #if LDBL_MANT_DIG == 64
36 two65 = 3.68934881474191032320e+19L; /* 0x4040, 0x80000000, 0x00000000 */
37 #else
38 # error "Cannot handle this MANT_DIG"
39 #endif
40
41
__frexpl(long double x,int * eptr)42 long double __frexpl(long double x, int *eptr)
43 {
44 uint32_t se, hx, ix, lx;
45 GET_LDOUBLE_WORDS(se,hx,lx,x);
46 ix = 0x7fff&se;
47 *eptr = 0;
48 if(ix==0x7fff||((ix|hx|lx)==0)) return x + x; /* 0,inf,nan */
49 if (ix==0x0000) { /* subnormal */
50 x *= two65;
51 GET_LDOUBLE_EXP(se,x);
52 ix = se&0x7fff;
53 *eptr = -65;
54 }
55 *eptr += ix-16382;
56 se = (se & 0x8000) | 0x3ffe;
57 SET_LDOUBLE_EXP(x,se);
58 return x;
59 }
60 libm_alias_ldouble (__frexp, frexp)
61