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b9b49b44 | 1 | /* Round float value to long long int. |
04277e02 | 2 | Copyright (C) 1997-2019 Free Software Foundation, Inc. |
b9b49b44 UD |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
41bdb6e2 AJ |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
b9b49b44 UD |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
41bdb6e2 | 13 | Lesser General Public License for more details. |
b9b49b44 | 14 | |
41bdb6e2 | 15 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 | 16 | License along with the GNU C Library; if not, see |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
b9b49b44 UD |
18 | |
19 | #include <math.h> | |
d7025bad JM |
20 | #include <math_private.h> |
21 | #include <stdint.h> | |
216933b2 | 22 | #include <libm-alias-float.h> |
b9b49b44 | 23 | |
da13146d AM |
24 | /* Round to the nearest integer, with values exactly on a 0.5 boundary |
25 | rounded away from zero, regardless of the current rounding mode. | |
26 | If (long long)x, when x is out of range of a long long, clips at | |
27 | LLONG_MAX or LLONG_MIN, then this implementation also clips. */ | |
b9b49b44 UD |
28 | |
29 | long long int | |
30 | __llroundf (float x) | |
31 | { | |
d7025bad JM |
32 | long long xr; |
33 | if (HAVE_PPC_FCTIDZ) | |
34 | xr = (long long) x; | |
35 | else | |
36 | { | |
37 | float ax = fabsf (x); | |
38 | /* Avoid incorrect exceptions from libgcc conversions (as of GCC | |
39 | 5): <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59412>. */ | |
40 | if (ax < 0x1p31f) | |
41 | xr = (long long int) (long int) x; | |
42 | else if (!(ax < 0x1p55f)) | |
43 | xr = (long long int) (long int) (x * 0x1p-32f) << 32; | |
44 | else | |
45 | { | |
46 | uint32_t i0; | |
47 | GET_FLOAT_WORD (i0, x); | |
48 | int exponent = ((i0 >> 23) & 0xff) - 0x7f; | |
49 | unsigned long long int mant = (i0 & 0x7fffff) | 0x800000; | |
50 | mant <<= exponent - 23; | |
51 | xr = (long long int) ((i0 & 0x80000000) != 0 ? -mant : mant); | |
52 | } | |
53 | } | |
54 | /* Avoid spurious "inexact" converting LLONG_MAX to float, and from | |
55 | subtraction when the result is out of range, by returning early | |
56 | for arguments large enough that no rounding is needed. */ | |
57 | if (!(fabsf (x) < 0x1p23f)) | |
58 | return xr; | |
da13146d AM |
59 | float xrf = (float) xr; |
60 | ||
b9b49b44 | 61 | if (x >= 0.0) |
da13146d AM |
62 | { |
63 | if (x - xrf >= 0.5) | |
64 | xr += (long long) ((unsigned long long) xr + 1) > 0; | |
65 | } | |
b9b49b44 | 66 | else |
da13146d AM |
67 | { |
68 | if (xrf - x >= 0.5) | |
69 | xr -= (long long) ((unsigned long long) xr - 1) < 0; | |
70 | } | |
71 | return xr; | |
b9b49b44 | 72 | } |
216933b2 | 73 | libm_alias_float (__llround, llround) |