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Diffstat (limited to 'sysdeps/i386/fpu/fraiseexcpt.c')
-rw-r--r--sysdeps/i386/fpu/fraiseexcpt.c51
1 files changed, 37 insertions, 14 deletions
diff --git a/sysdeps/i386/fpu/fraiseexcpt.c b/sysdeps/i386/fpu/fraiseexcpt.c
index 90e992aaec..c6cd6d6672 100644
--- a/sysdeps/i386/fpu/fraiseexcpt.c
+++ b/sysdeps/i386/fpu/fraiseexcpt.c
@@ -32,44 +32,67 @@ feraiseexcept (int excepts)
/* First: invalid exception. */
if ((FE_INVALID & excepts) != 0)
{
- /* One example of a invalid operation is 0 * Infinity. */
- double d = 0.0 * HUGE_VAL;
+ /* One example of a invalid operation is 0.0 / 0.0. */
+ double d;
+ __asm__ ("fldz; fdiv %%st, %%st(0); fwait" : "=t" (d));
(void) &d;
- /* Now force the exception. */
- __asm__ ("fwait");
}
/* Next: division by zero. */
if ((FE_DIVBYZERO & excepts) != 0)
{
double d;
- __asm__ ("fld1; fldz; fdivp %%st, %%st(1); fwait" : "=t" (d));
+ __asm__ ("fldz; fld1; fdivp %%st, %%st(1); fwait" : "=t" (d));
(void) &d;
}
/* Next: overflow. */
if ((FE_OVERFLOW & excepts) != 0)
{
- long double d = LDBL_MAX * LDBL_MAX;
- (void) &d;
- /* Now force the exception. */
- __asm__ ("fwait");
+ /* 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__ ("fnstenv %0" : "=m" (*&temp));
+
+ /* Set the relevant bits. */
+ temp.status_word |= FE_OVERFLOW;
+
+ /* Put the new data in effect. */
+ __asm__ ("fldenv %0" : : "m" (*&temp));
+
+ /* And raise the exception. */
+ __asm__ ("fwait");
}
/* Next: underflow. */
if ((FE_UNDERFLOW & excepts) != 0)
{
- long double d = LDBL_MIN / 16.0;
- (void) &d;
- /* Now force the exception. */
- __asm__ ("fwait");
+ /* 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__ ("fnstenv %0" : "=m" (*&temp));
+
+ /* Set the relevant bits. */
+ temp.status_word |= FE_UNDERFLOW;
+
+ /* Put the new data in effect. */
+ __asm__ ("fldenv %0" : : "m" (*&temp));
+
+ /* And raise the exception. */
+ __asm__ ("fwait");
}
/* Last: inexact. */
if ((FE_INEXACT & excepts) != 0)
{
long double d;
- __asm__ ("fld1; fldpi; fdivp %%st, %%st(1); fwait" : "=t" (d));
+ __asm__ ("fmul %%st, %%st(0); fwait" : "=t" (d) : "0" (LDBL_MAX));
(void) &d;
}
}