Testcase:

#include <stdlib.h>

void t() { throw 0; }
void (*tt)() = t;
void f(int*__restrict a, int x, bool y) {
  for (int i = 0; i < x; ++i) {
    *a += 1;
    if (y) tt();
  }
}
void (*ff)(int*__restrict,int,bool) = f;
int main() {
  int a = 0;
  try {
    ff(&a, 10, true);
  } catch (...) {
    if (a != 1) abort();
  }
}

Runs to completion with clang -O0, aborts with clang -O2.

The problem is incomplete safety checks in LICM.

(Artificial testcase.)