Re: [PATCH] Implement ipa_vr hashing.

[Aldy Hernandez <aldyh@redhat.com>]

On 5/29/23 16:51, Martin Jambor wrote:
> Hi,
> 
> On Mon, May 22 2023, Aldy Hernandez via Gcc-patches wrote:
>> Implement hashing for ipa_vr.  When all is said and done, all these
>> patches incurr a 7.64% slowdown for ipa-cp, with is entirely covered by
>> the similar 7% increase in this area last week.  So we get type agnostic
>> ranges with "infinite" range precision close to free.
> 
> Do you know why/where this slow-down happens?  Do we perhaps want to
> limit the "infiniteness" a little somehow?

I addressed the slow down in another mail.

> 
> Also, jump functions live for a long time, have you looked at how memory
> hungry they become?  I hope that the hashing would be good at preventing
> any issues.

On a side-note, the caching does help.  On a (mistaken) hunch, I had
played around with removing caching for everything but UNDEFINED/VARYING 
and zero/nonzero to simplify things, but the cache hit ratio was still 
surprisingly high (+80%).  So good job there :-).

> 
> Generally, I think I OK with the patches if the impact on memory is not
> too bad, though I guess they depend on the one I looked at last week, so
> we may focus on that one first.

I'm not sure whether this was an OK for the other patches, given you 
approved the first patch, so I'll hold off until you give the go-ahead.

Thanks.
Aldy