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/* Round to integer generic implementation.
Copyright (C) 2019 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, see <http://www.gnu.org/licenses/>. */
#ifndef _ROUND_TO_INTEGER_H
#define _ROUND_TO_INTEGER_H
#include <fenv_private.h>
enum round_mode
{
CEIL
};
static inline void
set_fenv_mode (enum round_mode mode)
{
int rmode;
switch (mode)
{
case CEIL: rmode = FE_UPWARD; break;
default: rmode = FE_TONEAREST; break;
}
__fesetround_inline_nocheck (rmode);
}
static inline float
round_to_integer_float (enum round_mode mode, float x)
{
/* Ensure sNaN input is converted to qNaN. */
if (__glibc_unlikely (isnan (x)))
return x + x;
if (fabs (x) > 0x1p+23)
return x;
float r = x;
/* Save current FPU rounding mode and inexact state. */
fenv_t fe = fegetenv_register ();
set_fenv_mode (mode);
if (x > 0.0)
{
r += 0x1p+23;
r -= 0x1p+23;
r = fabs (r);
}
else if (x < 0.0)
{
r -= 0x1p+23;
r += 0x1p+23;
r = -fabs (r);
}
__builtin_mtfsf (0xff, fe);
return r;
}
static inline double
round_to_integer_double (enum round_mode mode, double x)
{
/* Ensure sNaN input is converted to qNaN. */
if (__glibc_unlikely (isnan (x)))
return x + x;
if (fabs (x) > 0x1p+52)
return x;
double r = x;
/* Save current FPU rounding mode and inexact state. */
fenv_t fe = fegetenv_register ();
set_fenv_mode (mode);
if (x > 0.0)
{
r += 0x1p+52;
r -= 0x1p+52;
r = fabs (r);
}
else if (x < 0.0)
{
r -= 0x1p+52;
r += 0x1p+52;
r = -fabs (r);
}
__builtin_mtfsf (0xff, fe);
return r;
}
#endif
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