Re: The Case for Rust (in any system)

That‘s  because you are a dork.  The point isn’t that calloc calls are
faster than vector allocations.   The point is that by changing the way you
deal with arrays (as objects that manage their own size, versus managing
the sizes using up front preallocations and dealing with their growth
yourself), we can exchange function calls for pointer dereferences.

An order of magnitude improvement just by reorganizing the way array
element access is performed.


On Fri, Sep 13, 2024 at 2:17 AM David Chisnall <theraven@freebsd.org> wrote:

> On 13 Sep 2024, at 02:34, Joe Schaefer <joesuf4@gmail.com> wrote:
> >
> > I just completed a month long project to port a C++ codebase that used
> vectors for array allocations back to using C‘s calloc. For a 15% increase
> in memory footprint, batch jobs that took three days to complete now finish
> in 10-12 hours.
>
> This sounds highly dubious given that std::vector is a very thin wrapper
> around malloc. From your description, I would expect the same speedup with
> some judicial use of .reserve().
>
> David