1 /* Copyright (C) 2011-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
20 #include <math_private.h>
21 #include <libm-alias-double.h>
24 * for non-zero, finite x
25 * x = frexp(arg,&exp);
26 * return a double fp quantity x such that 0.5 <= |x| <1.0
27 * and the corresponding binary exponent "exp". That is
29 * If arg is inf, 0.0, or NaN, then frexp(arg,&exp) returns arg
35 __frexp (double x
, int *eptr
)
38 EXTRACT_WORDS64 (ix
, x
);
39 int32_t ex
= 0x7ff & (ix
>> 52);
42 if (__glibc_likely (ex
!= 0x7ff && x
!= 0.0))
44 /* Not zero and finite. */
46 if (__glibc_unlikely (ex
== 0))
50 EXTRACT_WORDS64 (ix
, x
);
51 ex
= 0x7ff & (ix
>> 52);
55 ix
= (ix
& INT64_C (0x800fffffffffffff)) | INT64_C (0x3fe0000000000000);
56 INSERT_WORDS64 (x
, ix
);
59 /* Quiet signaling NaNs. */
65 libm_alias_double (__frexp
, frexp
)