diff options
Diffstat (limited to 'libm/i386/fraiseexcpt.c')
-rw-r--r-- | libm/i386/fraiseexcpt.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/libm/i386/fraiseexcpt.c b/libm/i386/fraiseexcpt.c new file mode 100644 index 000000000..fcb3d0e84 --- /dev/null +++ b/libm/i386/fraiseexcpt.c @@ -0,0 +1,118 @@ +/* Raise given exceptions. + Copyright (C) 1997,99,2000,01,02 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + 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; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#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) + { + /* One example of a invalid operation is 0.0 / 0.0. */ + double d; + __asm__ __volatile__ ("fldz; fdiv %%st, %%st(0); fwait" : "=t" (d)); + (void) &d; + } + + /* Next: division by zero. */ + if ((FE_DIVBYZERO & excepts) != 0) + { + double d; + __asm__ __volatile__ ("fldz; fld1; fdivp %%st, %%st(1); fwait" + : "=t" (d)); + (void) &d; + } + + /* Next: overflow. */ + if ((FE_OVERFLOW & excepts) != 0) + { + /* There is no way to raise only the overflow flag. Do it the + hard way. */ + fenv_t temp; + + /* Bah, we have to clear selected exceptions. Since there is no + `fldsw' instruction we have to do it the hard way. */ + __asm__ __volatile__ ("fnstenv %0" : "=m" (*&temp)); + + /* Set the relevant bits. */ + temp.__status_word |= FE_OVERFLOW; + + /* Put the new data in effect. */ + __asm__ __volatile__ ("fldenv %0" : : "m" (*&temp)); + + /* And raise the exception. */ + __asm__ __volatile__ ("fwait"); + } + + /* Next: underflow. */ + if ((FE_UNDERFLOW & excepts) != 0) + { + /* There is no way to raise only the underflow flag. Do it the + hard way. */ + fenv_t temp; + + /* Bah, we have to clear selected exceptions. Since there is no + `fldsw' instruction we have to do it the hard way. */ + __asm__ __volatile__ ("fnstenv %0" : "=m" (*&temp)); + + /* Set the relevant bits. */ + temp.__status_word |= FE_UNDERFLOW; + + /* Put the new data in effect. */ + __asm__ __volatile__ ("fldenv %0" : : "m" (*&temp)); + + /* And raise the exception. */ + __asm__ __volatile__ ("fwait"); + } + + /* Last: inexact. */ + if ((FE_INEXACT & excepts) != 0) + { + /* There is no way to raise only the inexact flag. Do it the + hard way. */ + fenv_t temp; + + /* Bah, we have to clear selected exceptions. Since there is no + `fldsw' instruction we have to do it the hard way. */ + __asm__ __volatile__ ("fnstenv %0" : "=m" (*&temp)); + + /* Set the relevant bits. */ + temp.__status_word |= FE_INEXACT; + + /* Put the new data in effect. */ + __asm__ __volatile__ ("fldenv %0" : : "m" (*&temp)); + + /* And raise the exception. */ + __asm__ __volatile__ ("fwait"); + } + + /* Success. */ + return 0; +} +libm_hidden_def(feraiseexcept) |