1 | /* frexpq.c -- __float128 version of s_frexp.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 | /* |
17 | * for non-zero x |
18 | * x = frexpq(arg,&exp); |
19 | * return a __float128 fp quantity x such that 0.5 <= |x| <1.0 |
20 | * and the corresponding binary exponent "exp". That is |
21 | * arg = x*2^exp. |
22 | * If arg is inf, 0.0, or NaN, then frexpq(arg,&exp) returns arg |
23 | * with *exp=0. |
24 | */ |
25 | |
26 | #include "quadmath-imp.h" |
27 | |
28 | static const __float128 |
29 | two114 = 2.0769187434139310514121985316880384E+34Q; /* 0x4071000000000000, 0 */ |
30 | |
31 | __float128 |
32 | frexpq (__float128 x, int *eptr) |
33 | { |
34 | uint64_t hx, lx, ix; |
35 | GET_FLT128_WORDS64(hx,lx,x); |
36 | ix = 0x7fffffffffffffffULL&hx; |
37 | *eptr = 0; |
38 | if(ix>=0x7fff000000000000ULL||((ix|lx)==0)) return x + x;/* 0,inf,nan */ |
39 | if (ix<0x0001000000000000ULL) { /* subnormal */ |
40 | x *= two114; |
41 | GET_FLT128_MSW64(hx,x); |
42 | ix = hx&0x7fffffffffffffffULL; |
43 | *eptr = -114; |
44 | } |
45 | *eptr += (ix>>48)-16382; |
46 | hx = (hx&0x8000ffffffffffffULL) | 0x3ffe000000000000ULL; |
47 | SET_FLT128_MSW64(x,hx); |
48 | return x; |
49 | } |
50 | |