https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80721
--- Comment #2 from Markus Eisenmann <meisenmann....@fh-salzburg.ac.at> ---
Hi!
(In reply to Richard Biener from comment #1)
> Confirmed. Isn't it enough to add, after
>
> else if (reinterpret_cast <char *> (e) + sz
> == reinterpret_cast <char *> (first_free_entry))
> {
> ...
>
> a
>
> else if (reinterpret_cast <char *> (e)
> < reinterpret_cast <char *> (first_free_entry))
> {
> // First is right of us, replace the head.
> free_entry *f = reinterpret_cast <free_entry *> (e);
> new (f) free_entry;
> f->next = first_free_entry;
> first_free_entry = f;
> }
>
> ? That's a much less intrusive (and hard to review) fix.
Okay, a less intrusive fix for issue a) [set in front, if free-list is empty
or starts with a non merge-able block on a higher address]
Instead of (sorry, not fully formatted as unified diff), my suggestion would:
allocated_entry *e = reinterpret_cast <allocated_entry *>
(reinterpret_cast <char *> (data) - offsetof (allocated_entry, data));
std::size_t sz = e->size;
- if (!first_free_entry)
+ if (!first_free_entry
+ || (reinterpret_cast <char *> (e) + sz
+ < reinterpret_cast <char *> (first_free_entry)))
{
// If the free list is empty just put the entry there.
free_entry *f = reinterpret_cast <free_entry *> (e);
new (f) free_entry;
f->size = sz;
- f->next = NULL;
+ f->next = first_free_entry;
first_free_entry = f;
}
else if (reinterpret_cast <char *> (e) + sz
I.e., set in front if first_free_entry = null or has to be first, because non
merge-able and a "right" item.
Note: Following Merging with head will be "is-as-is";
About issue b) - additional merging with direct right follower - I have to
think a little about ...
Best regards,
Markus
