[vta,trunk?] stabilize hashing of SSA names and builtin function DECLs
Wed Dec 10 10:08:00 GMT 2008
On Wed, Dec 10, 2008 at 4:59 AM, Alexandre Oliva <email@example.com> wrote:
>> On Wed, Oct 29, 2008 at 8:19 PM, Alexandre Oliva <firstname.lastname@example.org> wrote:
>>> On Oct 29, 2008, "Richard Guenther" <email@example.com> wrote:
>>>> + val = iterative_hash_host_wide_int (DECL_UID (SSA_NAME_VAR (t)), val);
>>>> + val = iterative_hash_host_wide_int (SSA_NAME_VERSION (t), val);
>>>> why both? I would say using SSA_NAME_VERSION should be enough?
>>> Enough, it is, sure. I figured rocking the boat a bit further might
>>> make for better hashing. No evidence of that, though.
>> The problem is that if you hash on DECL_UID as well, it will hide
>> problems where people are keeping ssa names that have been freed in
>> hash tables (since versions get reused but decl_uid would be
>> This has actually happened in the past
> I see. It doesn't seem to occur any more, but there's little point in
> doing more work when there's no indication it provides for better
> hashing *and* it might also hurt. So, here's an updated patch. I
> guess it's too late to fix this kind of bug in 4.4, though. Anyhow,
> ok for 4.5?
Ok for 4.5.
> Alexandre Oliva http://www.lsd.ic.unicamp.br/~oliva/
> You must be the change you wish to see in the world. -- Gandhi
> Be Free! -- http://FSFLA.org/ FSF Latin America board member
> Free Software Evangelist Red Hat Brazil Compiler Engineer
More information about the Gcc-patches