gcc/libgcc/config/i386/sfp-exceptions.c
2021-01-04 10:26:59 +01:00

95 lines
2.7 KiB
C

/*
* Copyright (C) 2012-2021 Free Software Foundation, Inc.
*
* This file 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, or (at your option) any
* later version.
*
* This file 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/>.
*/
#ifndef _SOFT_FLOAT
#include "sfp-machine.h"
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
void
__sfp_handle_exceptions (int _fex)
{
struct fenv temp;
if (_fex & FP_EX_INVALID)
{
float f = 0.0f;
__math_force_eval_div (f, f);
}
if (_fex & FP_EX_DENORM)
{
asm volatile ("fnstenv\t%0" : "=m" (temp));
temp.__status_word |= FP_EX_DENORM;
asm volatile ("fldenv\t%0" : : "m" (temp));
asm volatile ("fwait");
}
if (_fex & FP_EX_DIVZERO)
{
float f = 1.0f, g = 0.0f;
__math_force_eval_div (f, g);
}
if (_fex & FP_EX_OVERFLOW)
{
asm volatile ("fnstenv\t%0" : "=m" (temp));
temp.__status_word |= FP_EX_OVERFLOW;
asm volatile ("fldenv\t%0" : : "m" (temp));
asm volatile ("fwait");
}
if (_fex & FP_EX_UNDERFLOW)
{
asm volatile ("fnstenv\t%0" : "=m" (temp));
temp.__status_word |= FP_EX_UNDERFLOW;
asm volatile ("fldenv\t%0" : : "m" (temp));
asm volatile ("fwait");
}
if (_fex & FP_EX_INEXACT)
{
float f = 1.0f, g = 3.0f;
__math_force_eval_div (f, g);
}
}
#endif