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 | |
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 | |