91 lines
2.8 KiB
C
91 lines
2.8 KiB
C
/* Raise given exceptions.
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Copyright (C) 1997, 1999, 2000 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by David Huggins-Daines <dhd@debian.org>
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <fenv.h>
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#include <float.h>
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#include <math.h>
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int
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feraiseexcept (int excepts)
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{
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/* Raise exceptions represented by EXCEPTS. But we must raise only one
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signal at a time. It is important that if the overflow/underflow
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exception and the divide by zero exception are given at the same
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time, the overflow/underflow exception follows the divide by zero
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exception. */
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/* We do these bits in assembly to be certain GCC doesn't optimize
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away something important, and so we can force delayed traps to
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occur. */
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/* FIXME: These all need verification! */
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/* First: invalid exception. */
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if (excepts & FE_INVALID)
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{
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/* One example of a invalid operation is 0 * Infinity. */
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double d = HUGE_VAL;
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__asm__ __volatile__ ("fmpy,dbl %1,%%fr0,%0\n\t"
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/* FIXME: is this a proper trap barrier? */
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"fcpy,dbl %%fr0,%%fr0" : "=f" (d) : "0" (d));
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}
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/* Next: division by zero. */
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if (excepts & FE_DIVBYZERO)
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{
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double d = 1.0;
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__asm__ __volatile__ ("fdiv,dbl %1,%%fr0,%0\n\t"
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"fcpy,dbl %%fr0,%%fr0" : "=f" (d) : "0" (d));
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}
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/* Next: overflow. */
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/* FIXME: Compare with IA-64 - do we have the same problem? */
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if (excepts & FE_OVERFLOW)
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{
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double d = DBL_MAX;
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__asm__ __volatile__ ("fmpy,dbl %1,%1,%0\n\t"
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"fcpy,dbl %%fr0,%%fr0" : "=f" (d) : "0" (d));
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}
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/* Next: underflow. */
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if (excepts & FE_UNDERFLOW)
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{
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double d = DBL_MIN;
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double e = 69.69;
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__asm__ __volatile__ ("fdiv,dbl %1,%2,%0\n\t"
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"fcpy,dbl %%fr0,%%fr0" : "=f" (d) : "0" (d), "f" (e));
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}
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/* Last: inexact. */
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if (excepts & FE_INEXACT)
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{
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double d = 1.0;
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double e = M_PI;
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__asm__ __volatile__ ("fdiv,dbl %1,%2,%0\n\t"
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"fcpy,dbl %%fr0,%%fr0" : "=f" (d) : "0" (d), "f" (e));
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}
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/* Success. */
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return 0;
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}
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