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Re: Simplify and speed up uniquify (issue 583390043 by address@hidden)
From: |
dak |
Subject: |
Re: Simplify and speed up uniquify (issue 583390043 by address@hidden) |
Date: |
Fri, 24 Jan 2020 08:11:37 -0800 |
On 2020/01/24 15:50:22, Dan Eble wrote:
> On 2020/01/24 15:17:02, dak wrote:
> > On 2020/01/24 14:11:59, Dan Eble wrote:
> > > On 2020/01/24 14:06:22, hanwenn wrote:
> > > > If the allocation cost becomes problematic, we can use another
hashmap
> > > instead.
> > >
> > > "We" could profile it and know before pushing whether it is worth
it.
> >
> > I don't think that this is really performance-critical.
>
> I accept your informed intuition, but I also have more suggestions.
>
> Don't assume the hash function is perfect: create the table with more
buckets,
> say 2*size.
I'd not do that. It's second-guessing the implementation. The size
should be good as a hint. In particular if there are actual
duplicates...
> Instead of calling find() then insert(), just call insert() and check
whether it
> worked, something like this (untested):
>
> if (seen.insert(grobs[i]).second)
> grobs[j++] = grobs[i];
Ok, that's a good idea.
> https://en.cppreference.com/w/cpp/container/unordered_set/insert
https://codereview.appspot.com/583390043/
- Simplify and speed up uniquify (issue 583390043 by address@hidden), dak, 2020/01/24
- Re: Simplify and speed up uniquify (issue 583390043 by address@hidden), hanwenn, 2020/01/24
- Re: Simplify and speed up uniquify (issue 583390043 by address@hidden), nine . fierce . ballads, 2020/01/24
- Re: Simplify and speed up uniquify (issue 583390043 by address@hidden), dak, 2020/01/24
- Re: Simplify and speed up uniquify (issue 583390043 by address@hidden), dak, 2020/01/24
- Re: Simplify and speed up uniquify (issue 583390043 by address@hidden), hanwenn, 2020/01/24
- Re: Simplify and speed up uniquify (issue 583390043 by address@hidden), nine . fierce . ballads, 2020/01/24
- Re: Simplify and speed up uniquify (issue 583390043 by address@hidden),
dak <=
- Re: Simplify and speed up uniquify (issue 583390043 by address@hidden), hanwenn, 2020/01/25