diff options
Diffstat (limited to 'sysdeps/i386/fpu/fraiseexcpt.c')
-rw-r--r-- | sysdeps/i386/fpu/fraiseexcpt.c | 51 |
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; } } |