diff options
Diffstat (limited to 'sysdeps/x86_64/fpu/fraiseexcpt.c')
| -rw-r--r-- | sysdeps/x86_64/fpu/fraiseexcpt.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/sysdeps/x86_64/fpu/fraiseexcpt.c b/sysdeps/x86_64/fpu/fraiseexcpt.c new file mode 100644 index 0000000000..96ebb6dea2 --- /dev/null +++ b/sysdeps/x86_64/fpu/fraiseexcpt.c @@ -0,0 +1,119 @@ +/* Raise given exceptions. + Copyright (C) 2001 Free Software Foundation, Inc. + 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; 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> + +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. */ + float f = 0.0; + + __asm__ __volatile__ ("divss %0, %0 " : : "x" (f)); + (void) &f; + } + + /* Next: division by zero. */ + if ((FE_DIVBYZERO & excepts) != 0) + { + float f = 1.0; + float g = 0.0; + + __asm__ __volatile__ ("divss %1, %0" : : "x" (f), "x" (g)); + (void) &f; + } + + /* Next: overflow. */ + if ((FE_OVERFLOW & excepts) != 0) + { + /* XXX: Is it ok to only set the x87 FPU? */ + /* 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) + { + /* XXX: Is it ok to only set the x87 FPU? */ + /* 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) + { + /* XXX: Is it ok to only set the x87 FPU? */ + /* 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; +} |