| /* Round double value to long long int. |
| Copyright (C) 1997-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <limits.h> |
| #include <math.h> |
| #include <math_ldbl_opt.h> |
| #include <math_private.h> |
| #include <stdint.h> |
| #include <libm-alias-double.h> |
| |
| /* Round to the nearest integer, with values exactly on a 0.5 boundary |
| rounded away from zero, regardless of the current rounding mode. |
| If (long long)x, when x is out of range of a long long, clips at |
| LLONG_MAX or LLONG_MIN, then this implementation also clips. */ |
| |
| long long int |
| __llround (double x) |
| { |
| long long xr; |
| if (HAVE_PPC_FCTIDZ) |
| xr = (long long) x; |
| else |
| { |
| /* Avoid incorrect exceptions from libgcc conversions (as of GCC |
| 5): <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59412>. */ |
| if (fabs (x) < 0x1p31) |
| xr = (long long int) (long int) x; |
| else |
| { |
| uint64_t i0; |
| EXTRACT_WORDS64 (i0, x); |
| int exponent = ((i0 >> 52) & 0x7ff) - 0x3ff; |
| if (exponent < 63) |
| { |
| unsigned long long int mant |
| = (i0 & ((1ULL << 52) - 1)) | (1ULL << 52); |
| if (exponent < 52) |
| /* llround is not required to raise "inexact". */ |
| mant >>= 52 - exponent; |
| else |
| mant <<= exponent - 52; |
| xr = (long long int) ((i0 & (1ULL << 63)) != 0 ? -mant : mant); |
| } |
| else if (x == (double) LLONG_MIN) |
| xr = LLONG_MIN; |
| else |
| xr = (long long int) (long int) x << 32; |
| } |
| } |
| /* Avoid spurious "inexact" converting LLONG_MAX to double, and from |
| subtraction when the result is out of range, by returning early |
| for arguments large enough that no rounding is needed. */ |
| if (!(fabs (x) < 0x1p52)) |
| return xr; |
| double xrf = (double) xr; |
| |
| if (x >= 0.0) |
| { |
| if (x - xrf >= 0.5) |
| xr += (long long) ((unsigned long long) xr + 1) > 0; |
| } |
| else |
| { |
| if (xrf - x >= 0.5) |
| xr -= (long long) ((unsigned long long) xr - 1) < 0; |
| } |
| return xr; |
| } |
| libm_alias_double (__llround, llround) |
