[Bug target/81863] [7 regression] -mword-relocations is unreliable

["arnd at linaro dot org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81863

--- Comment #3 from Arnd Bergmann <arnd at linaro dot org> ---
The __builtin_prefetch() that caused the problem in the test case from comment
2 might be a red herring, I already noticed earlier that the bug shows up both
in configurations that use a built-in function and an inline assembler version
of the same. I reduced the other one as well now, coming to almost the same
reduced source:

int a, e, f, g, h;
struct ww_class {
  int stamp;
} c;
struct stress {
  int locks;
  int nlocks;
} d;
void *i;
int fn1(int *p1) {
  void *b = p1;
  __asm__("" ::"p"(b));
  return a;
}
void fn2(int *p1) {
  int *v = p1;
  fn1(v);
}
void fn3(struct ww_class *p1) { fn2(&p1->stamp); }
void fn4();
void fn5() {
  struct stress *j = i;
  int k = j->nlocks;
  int *l = &j->locks;
  do {
    fn3(&c);
  retry:
    for (g = 0; g < k;)
      fn4(l[e], d);
    f = g;
    if (h)
      goto retry;
  } while (!0);
}