Hi,
The benchmarks are updated since a while back, all versions use 64 bit
values, and there are different versions for jemalloc and the glibc
allocator (for Rust and C).
As noted by Daniel Micay the most important factor here will be the memory
allocator. Rust builds with jemalloc by default, which compared to the
glibc allocator on my Linux system is about twice as slow. Without knowing
anything about your system a likely cause could be that the allocator used
for the C version on your system is not the glibc allocator.
The timing operation is run every 1/10^6 iteration (or 1/10^7 in your
case), so optimizing it should not typically change the result.
F
On Fri, Sep 26, 2014 at 9:21 PM, François-Xavier Bourlet <bomb...@gmail.com>
wrote:
> with i32 for rust:
> (I am on x86_64)
>
> ==> vector_grow_c.csv <==
> 1000000000,4.741286
>
> ==> vector_grow_rust.csv <==
> 1000000000,3.147506
>
> ==> vector_grow_rust2.csv <==
> 1000000000,3.153482
>
> On Thu, Sep 25, 2014 at 9:30 PM, Clark Gaebel <cg.wowus...@gmail.com>
> wrote:
> > Another problem I noticed is that the elements in the vector in the rust
> > code are `uint` (which on most systems is 64-bit) and in the C code
> you’re
> > inserting `int`s (32-bits on most systems).
> >
> > That’s not really a fair contest.
> >
> > - Clark
> >
> >
> >
> > On Thu, Sep 25, 2014 at 6:26 PM, François-Xavier Bourlet <
> bomb...@gmail.com>
> > wrote:
> >>
> >> and hitting reply-all is better...
> >>
> >> quick update: the implementation with unsafe & ptr is not slower. I
> >> just have too many cores + power-boost to get a clean benchmark every
> >> time.
> >> Running the benchs with n=1 billions (instead of 100 millions) gives me:
> >>
> >>
> >> ==> vector_grow_c.csv <==
> >> 1000000000,5.084604
> >>
> >> ==> vector_grow_rust.csv <==
> >> 1000000000,5.217096
> >>
> >> ==> vector_grow_rust2.csv <==
> >> 1000000000,4.912147 (yes, getting rid of the second push works!)
> >>
> >> $ rustc --version
> >> rustc 0.12.0-pre-nightly (0e784e168 2014-09-16 23:26:11 +0000)
> >> $ gcc --version
> >> gcc (GCC) 4.9.1
> >>
> >> On Thu, Sep 25, 2014 at 6:18 PM, François-Xavier Bourlet
> >> <bomb...@gmail.com> wrote:
> >> > On my machine I get:
> >> >
> >> > C: 100000000,0.509391
> >> > rust: 100000000,0.466069
> >> >
> >> > So rust is faster for me.
> >> >
> >> > For fun, I tried to write the rust version using unsafe and
> >> > pre-allocation to remove the second push:
> >> >
> >> > let mut m = Vec::from_fn(101, |_| 0);
> >> > let pm = m.as_mut_ptr();
> >> > let mut m_idx = 1i;
> >> > let t = time::precise_time_ns();
> >> > for _i in iter::range_step(0, n, n/100) {
> >> > for j in range(0, n/100) {
> >> > v.push(j);
> >> > }
> >> > unsafe {
> >> > ptr::write(pm.offset(m_idx as int), time::precise_time_ns() - t);
> >> > }
> >> > m_idx += 1;
> >> > }
> >> >
> >> > But I get a little slower result (maybe I am doing something wrong
> >> > with the unsafe and ptr):
> >> > rust2: 100000000,0.472749
> >> >
> >> > And just to be sure, I tested getting rid of iterators (using manual
> >> > while loop instead) and this changed nothing (as expected).
> >> >
> >> > my 2 cents
> >> >
> >> >
> >> > On Thu, Sep 25, 2014 at 4:05 PM, Clark Gaebel <cg.wowus...@gmail.com>
> >> > wrote:
> >> >> You’re also timing two pushes, as opposed to a push and an array
> write
> >> >> in
> >> >> the C version.
> >> >>
> >> >>
> >> >>
> >> >> On Thu, Sep 25, 2014 at 3:59 PM, Daniel Micay <danielmi...@gmail.com
> >
> >> >> wrote:
> >> >>>
> >> >>> <signature.asc>
> >> >>
> >> >>
> >> >>
> >> >> _______________________________________________
> >> >> Rust-dev mailing list
> >> >> Rust-dev@mozilla.org
> >> >> https://mail.mozilla.org/listinfo/rust-dev
> >> >>
> >
> >
> _______________________________________________
> Rust-dev mailing list
> Rust-dev@mozilla.org
> https://mail.mozilla.org/listinfo/rust-dev
>
_______________________________________________
Rust-dev mailing list
Rust-dev@mozilla.org
https://mail.mozilla.org/listinfo/rust-dev
