gcc/testsuite/gcc.c-torture/execute/vrp-1.c

extern void abort ();
extern void exit (int);

int f (int a) {
	if (a != 2) {
		a = -a;
		if (a == 2)
		  return 0;
		return 1;
	}
	return 1;
}

int main (int argc, char *argv[]) {
	if (f (-2))
		abort ();
	exit (0);
}