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/* Raise given exceptions.
Copyright (C) 2013 Imagination Technologies Ltd.
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; see the file COPYING.LIB. If
not, see <http://www.gnu.org/licenses/>. */
#include <fenv.h>
#include <math.h>
libm_hidden_proto(feraiseexcept)
int
feraiseexcept (int excepts)
{
/* Raise exceptions represented by EXPECTS. But we must raise only
one signal at a time. It is important that if the overflow/underflow
exception and the inexact exception are given at the same time,
the overflow/underflow exception follows the inexact exception. */
/* First: invalid exception. */
if ((FE_INVALID & excepts) != 0)
{
/* Reciprocal square root of a negative number is invalid. */
__asm__ volatile(
"F MOV FX.0,#0xc000 ! -2\n"
"F RSQ FX.1,FX.0\n"
);
}
/* Next: division by zero. */
if ((FE_DIVBYZERO & excepts) != 0)
{
__asm__ volatile(
"F MOV FX.0,#0\n"
"F RCP FX.1,FX.0\n"
);
}
/* Next: overflow. */
if ((FE_OVERFLOW & excepts) != 0)
{
/* Adding a large number in single precision can cause overflow. */
__asm__ volatile(
" MOVT D0.0,#0x7f7f\n"
" ADD D0.0,D0.0,#0xffff\n"
"F MOV FX.0,D0.0\n"
"F ADD FX.1,FX.0,FX.0\n"
);
}
/* Next: underflow. */
if ((FE_UNDERFLOW & excepts) != 0)
{
/* Multiplying a small value by 0.5 will cause an underflow. */
__asm__ volatile(
" MOV D0.0,#1\n"
"F MOV FX.0,D0.0\n"
" MOVT D0.0,#0x3f00\n"
"F MOV FX.1,D0.0\n"
"F MUL FX.2,FX.1,FX.0\n"
);
}
/* Last: inexact. */
if ((FE_INEXACT & excepts) != 0)
{
/* Converting a small single precision value to half precision
can cause an inexact exception. */
__asm__ volatile(
" MOV D0.0,#0x0001\n"
"F MOV FX.0,D0.0\n"
"F FTOH FX.1,FX.0\n"
);
}
/* Success. */
return 0;
}
libm_hidden_def(feraiseexcept)
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