Add object allocators to symbol and call summaries

[Martin Liška]

On 11/5/19 11:36 AM, Jan Hubicka wrote:
> Hi,
> this patch adds object allocators to manage IPA summaries. This reduces
> malloc overhead and fragmentation.  I now get peak memory use 7.5GB instead
> of 10GB for firefox WPA because reduced fragmentation leads to less COWs after
> forks.

That sounds promising.

> Additional bonus is that we now have statistics gathered by mem-reports
> which makes my life easier, too.

What's currently bad with the detailed memory statistics? I updated the
code that one should see the allocation for the underlying hash_map and
vec?

> (though memory stats are far from ideal - we need to pass location info around
> bit more).

Please rename allocator to m_allocator.

Martin