https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112843
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #2)
> what?! Ick. It definitely shouldn't re-fold anything but only scrap caches
> _at most_.
So it does
// Only update if it already had a value.
if (m_cache.get_global_range (r, lhs))
{
// Re-calculate a new value using just cache values.
Value_Range tmp (TREE_TYPE (lhs));
fold_using_range f;
fur_stmt src (s, &m_cache);
f.fold_stmt (tmp, s, src, lhs);
// Combine the new value with the old value to check for a change.
if (r.intersect (tmp))
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
print_generic_expr (dump_file, lhs, TDF_SLIM);
fprintf (dump_file, " : global value re-evaluated to ");
r.dump (dump_file);
fputc ('\n', dump_file);
}
m_cache.set_global_range (lhs, r);
WTF? If a pass invalidates a range it needs to properly do this itself.
But update_stmt itself _never_ should alter range info.
