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/* $OpenBSD: except.c,v 1.6 2004/04/02 03:06:12 mickey Exp $ */
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <assert.h>
#include <ieeefp.h>
#include <float.h>
volatile sig_atomic_t signal_caught;
volatile const double one = 1.0;
volatile const double zero = 0.0;
volatile const double huge = DBL_MAX;
volatile const double tiny = DBL_MIN;
void
sigfpe(int sig, siginfo_t *si, void *v)
{
char buf[132];
if (si) {
snprintf(buf, sizeof(buf), "sigfpe: addr=%p, code=%d\n",
si->si_addr, si->si_code);
write(1, buf, strlen(buf));
}
signal_caught = 1;
}
int
main(int argc, char *argv[])
{
struct sigaction sa;
volatile double x;
/*
* check to make sure that all exceptions are masked and
* that the accumulated exception status is clear.
*/
assert(fpgetmask() == 0);
assert(fpgetsticky() == 0);
memset(&sa, 0, sizeof(sa));
sa.sa_sigaction = sigfpe;
sa.sa_flags = SA_SIGINFO;
sigaction(SIGFPE, &sa, NULL);
signal_caught = 0;
/* trip divide by zero */
x = one / zero;
assert(fpgetsticky() & FP_X_DZ);
assert(signal_caught == 0);
fpsetsticky(0);
/* trip invalid operation */
x = zero / zero;
assert(fpgetsticky() & FP_X_INV);
assert(signal_caught == 0);
fpsetsticky(0);
/* trip overflow */
x = huge * huge;
assert(fpgetsticky() & FP_X_OFL);
assert(signal_caught == 0);
fpsetsticky(0);
/* trip underflow */
x = tiny * tiny;
assert(fpgetsticky() & FP_X_UFL);
assert(signal_caught == 0);
fpsetsticky(0);
/* unmask and then trip divide by zero */
fpsetmask(FP_X_DZ);
x = one / zero;
assert(signal_caught == 1);
signal_caught = 0;
/* unmask and then trip invalid operation */
fpsetmask(FP_X_INV);
x = zero / zero;
assert(signal_caught == 1);
signal_caught = 0;
/* unmask and then trip overflow */
fpsetmask(FP_X_OFL);
x = huge * huge;
assert(signal_caught == 1);
signal_caught = 0;
/* unmask and then trip underflow */
fpsetmask(FP_X_UFL);
x = tiny * tiny;
assert (signal_caught == 1);
signal_caught = 0;
exit(0);
}
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