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/* Round float value to long long int.
Copyright (C) 1997-2020 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
<https://www.gnu.org/licenses/>. */
#include <math.h>
#include <math_private.h>
#include <stdint.h>
#include <libm-alias-float.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
__llroundf (float x)
{
long long xr;
if (HAVE_PPC_FCTIDZ)
xr = (long long) x;
else
{
float ax = fabsf (x);
/* Avoid incorrect exceptions from libgcc conversions (as of GCC
5): <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59412>. */
if (ax < 0x1p31f)
xr = (long long int) (long int) x;
else if (!(ax < 0x1p55f))
xr = (long long int) (long int) (x * 0x1p-32f) << 32;
else
{
uint32_t i0;
GET_FLOAT_WORD (i0, x);
int exponent = ((i0 >> 23) & 0xff) - 0x7f;
unsigned long long int mant = (i0 & 0x7fffff) | 0x800000;
mant <<= exponent - 23;
xr = (long long int) ((i0 & 0x80000000) != 0 ? -mant : mant);
}
}
/* Avoid spurious "inexact" converting LLONG_MAX to float, and from
subtraction when the result is out of range, by returning early
for arguments large enough that no rounding is needed. */
if (!(fabsf (x) < 0x1p23f))
return xr;
float xrf = (float) 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_float (__llround, llround)
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