This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: mem_attrs_htab
On Mon, Aug 22, 2011 at 12:07 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Mon, Aug 22, 2011 at 11:57:18AM +0200, Richard Guenther wrote:
>> And at some point the idea popped up to just dump this whole re-using
>> mem-attrs. ?There is at most a single function in RTL but the whole program
>> is available in SSA, so the memory overhead must be small.
>
> Some functions are extremely large though. ?Do you mean that MEM itself would be
> enlarged to have the MEM_ATTRS field so that one operand is the address,
> then expr, then HWI size, offset, etc.? ?Because if the mem attrs aren't
> shared any longer, it doesn't make sense to keep the indirection.
> I still fear we have way too many MEMs in RTL that this would be noticeable.
It would be interesting to have numbers about the amount of sharing that
happens - might be not trivial though, as some re-uses would be able to
simply modify the attr inplace.
Richard.
> ? ? ? ?Jakub
>