62 lines
1.7 KiB
C
62 lines
1.7 KiB
C
|
#include <stdlib.h>
|
||
|
|
#include <assert.h>
|
||
|
|
#include <signal.h>
|
||
|
|
#include <sys/prctl.h>
|
||
|
|
|
||
|
|
#define FPSCR_VE 7 /* Floating-point invalid operation exception enable */
|
||
|
|
#define FPSCR_VXSOFT 10 /* Floating-point invalid operation exception (soft) */
|
||
|
|
#define FPSCR_FI 17 /* Floating-point fraction inexact */
|
||
|
|
|
||
|
|
#define FP_VE (1ull << FPSCR_VE)
|
||
|
|
#define FP_VXSOFT (1ull << FPSCR_VXSOFT)
|
||
|
|
#define FP_FI (1ull << FPSCR_FI)
|
||
|
|
|
||
|
|
void sigfpe_handler(int sig, siginfo_t *si, void *ucontext)
|
||
|
|
{
|
||
|
|
if (si->si_code == FPE_FLTINV) {
|
||
|
|
exit(0);
|
||
|
|
}
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
|
||
|
|
int main(void)
|
||
|
|
{
|
||
|
|
union {
|
||
|
|
double d;
|
||
|
|
long long ll;
|
||
|
|
} fpscr;
|
||
|
|
|
||
|
|
struct sigaction sa = {
|
||
|
|
.sa_sigaction = sigfpe_handler,
|
||
|
|
.sa_flags = SA_SIGINFO
|
||
|
|
};
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Enable the MSR bits F0 and F1 to enable exceptions.
|
||
|
|
* This shouldn't be needed in linux-user as these bits are enabled by
|
||
|
|
* default, but this allows to execute either in a VM or a real machine
|
||
|
|
* to compare the behaviors.
|
||
|
|
*/
|
||
|
|
prctl(PR_SET_FPEXC, PR_FP_EXC_PRECISE);
|
||
|
|
|
||
|
|
/* First test if the FI bit is being set correctly */
|
||
|
|
fpscr.ll = FP_FI;
|
||
|
|
__builtin_mtfsf(0b11111111, fpscr.d);
|
||
|
|
fpscr.d = __builtin_mffs();
|
||
|
|
assert((fpscr.ll & FP_FI) != 0);
|
||
|
|
|
||
|
|
/* Then test if the deferred exception is being called correctly */
|
||
|
|
sigaction(SIGFPE, &sa, NULL);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Although the VXSOFT exception has been chosen, based on test in a Power9
|
||
|
|
* any combination of exception bit + its enabling bit should work.
|
||
|
|
* But if a different exception is chosen si_code check should
|
||
|
|
* change accordingly.
|
||
|
|
*/
|
||
|
|
fpscr.ll = FP_VE | FP_VXSOFT;
|
||
|
|
__builtin_mtfsf(0b11111111, fpscr.d);
|
||
|
|
|
||
|
|
return 1;
|
||
|
|
}
|