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authorBernhard Reutner-Fischer <rep.dot.nop@gmail.com>2008-01-19 15:23:14 +0000
committerBernhard Reutner-Fischer <rep.dot.nop@gmail.com>2008-01-19 15:23:14 +0000
commitbce5bba7a01fb090f67fec5f79218c505c841af3 (patch)
treee7d7dfc12cae1f1474800071fbc4633fa509ef6e /libm/i386/fraiseexcpt.c
parentd22976dd5e16e8719abd5c542e17427eeece7ff6 (diff)
- add C99 floating point environment, rounding and exception handling functions
for i386. UCLIBC_HAS_FENV
Diffstat (limited to 'libm/i386/fraiseexcpt.c')
-rw-r--r--libm/i386/fraiseexcpt.c118
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)