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/* Copyright (C) 2013-2020 Free Software Foundation, Inc.
This file is part of the GNU Atomic Library (libatomic).
Libatomic is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
Libatomic 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 General Public License for
more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#include "libatomic_i.h"
#define FE_INVALID 0x01
#define FE_DENORM 0x02
#define FE_DIVBYZERO 0x04
#define FE_OVERFLOW 0x08
#define FE_UNDERFLOW 0x10
#define FE_INEXACT 0x20
struct fenv
{
unsigned short int __control_word;
unsigned short int __unused1;
unsigned short int __status_word;
unsigned short int __unused2;
unsigned short int __tags;
unsigned short int __unused3;
unsigned int __eip;
unsigned short int __cs_selector;
unsigned int __opcode:11;
unsigned int __unused4:5;
unsigned int __data_offset;
unsigned short int __data_selector;
unsigned short int __unused5;
} __attribute__ ((gcc_struct));
#ifdef __SSE_MATH__
# define __math_force_eval_div(x, y) \
do { asm ("" : "+x" (x)); asm volatile ("" : : "x" (x / y)); } while (0)
#else
# define __math_force_eval_div(x, y) \
do { asm ("" : "+t" (x)); asm volatile ("" : : "f" (x / y)); } while (0)
#endif
/* Raise the supported floating-point exceptions from EXCEPTS. Other
bits in EXCEPTS are ignored. */
void
__atomic_feraiseexcept (int excepts)
{
struct fenv temp;
if (excepts & FE_INVALID)
{
float f = 0.0f;
__math_force_eval_div (f, f);
}
if (excepts & FE_DENORM)
{
asm volatile ("fnstenv\t%0" : "=m" (temp));
temp.__status_word |= FE_DENORM;
asm volatile ("fldenv\t%0" : : "m" (temp));
asm volatile ("fwait");
}
if (excepts & FE_DIVBYZERO)
{
float f = 1.0f, g = 0.0f;
__math_force_eval_div (f, g);
}
if (excepts & FE_OVERFLOW)
{
asm volatile ("fnstenv\t%0" : "=m" (temp));
temp.__status_word |= FE_OVERFLOW;
asm volatile ("fldenv\t%0" : : "m" (temp));
asm volatile ("fwait");
}
if (excepts & FE_UNDERFLOW)
{
asm volatile ("fnstenv\t%0" : "=m" (temp));
temp.__status_word |= FE_UNDERFLOW;
asm volatile ("fldenv\t%0" : : "m" (temp));
asm volatile ("fwait");
}
if (excepts & FE_INEXACT)
{
float f = 1.0f, g = 3.0f;
__math_force_eval_div (f, g);
}
}
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