ff6c6ce917
Improve siphash performance for longer data Use `ptr::copy_nonoverlapping` (aka memcpy) to load an u64 from the byte stream. This is correct for any alignment, and the compiler will use the appropriate instruction to load the data. Also contains small tweaks that should benefit hashing short data too, both the commit that removes a variable and the autovectorization of the hash state initialization (in SipHash::reset). Benchmarks show that hashing longer data benefits for the improved word loading. Before (using benchmarks from the first commit in the PR): The before benchmark is a bit noisy. ``` test hash::sip::bench_bytes_4 ... bench: 41 ns/iter (+/- 0) = 97 MB/s test hash::sip::bench_bytes_7 ... bench: 49 ns/iter (+/- 2) = 142 MB/s test hash::sip::bench_bytes_8 ... bench: 42 ns/iter (+/- 4) = 190 MB/s test hash::sip::bench_bytes_a_16 ... bench: 57 ns/iter (+/- 14) = 280 MB/s test hash::sip::bench_bytes_b_32 ... bench: 85 ns/iter (+/- 74) = 376 MB/s test hash::sip::bench_bytes_c_128 ... bench: 278 ns/iter (+/- 33) = 460 MB/s test hash::sip::bench_long_str ... bench: 825 ns/iter (+/- 103) test hash::sip::bench_str_of_8_bytes ... bench: 151 ns/iter (+/- 66) test hash::sip::bench_str_over_8_bytes ... bench: 59 ns/iter (+/- 3) test hash::sip::bench_str_under_8_bytes ... bench: 47 ns/iter (+/- 56) test hash::sip::bench_u32 ... bench: 39 ns/iter (+/- 93) = 205 MB/s test hash::sip::bench_u32_keyed ... bench: 40 ns/iter (+/- 88) = 200 MB/s test hash::sip::bench_u64 ... bench: 54 ns/iter (+/- 96) = 148 MB/s ``` After: ``` test hash::sip::bench_bytes_4 ... bench: 41 ns/iter (+/- 3) = 97 MB/s test hash::sip::bench_bytes_7 ... bench: 48 ns/iter (+/- 0) = 145 MB/s test hash::sip::bench_bytes_8 ... bench: 35 ns/iter (+/- 1) = 228 MB/s test hash::sip::bench_bytes_a_16 ... bench: 45 ns/iter (+/- 1) = 355 MB/s test hash::sip::bench_bytes_b_32 ... bench: 60 ns/iter (+/- 0) = 533 MB/s test hash::sip::bench_bytes_c_128 ... bench: 161 ns/iter (+/- 5) = 795 MB/s test hash::sip::bench_long_str ... bench: 514 ns/iter (+/- 5) test hash::sip::bench_str_of_8_bytes ... bench: 44 ns/iter (+/- 0) test hash::sip::bench_str_over_8_bytes ... bench: 51 ns/iter (+/- 0) test hash::sip::bench_str_under_8_bytes ... bench: 52 ns/iter (+/- 6) test hash::sip::bench_u32 ... bench: 40 ns/iter (+/- 2) = 200 MB/s test hash::sip::bench_u32_keyed ... bench: 39 ns/iter (+/- 1) = 205 MB/s test hash::sip::bench_u64 ... bench: 36 ns/iter (+/- 1) = 222 MB/s ```
The Rust Programming Language
Rust is a fast systems programming language that guarantees memory safety and offers painless concurrency (no data races). It does not employ a garbage collector and has minimal runtime overhead.
This repo contains the code for the compiler (rustc), as well
as standard libraries, tools and documentation for Rust.
Quick Start
Read "Installing Rust" from The Book.
Building from Source
-
Make sure you have installed the dependencies:
g++4.7 orclang++3.xpython2.6 or later (but not 3.x)- GNU
make3.81 or later curlgit
-
Clone the source with
git:$ git clone https://github.com/rust-lang/rust.git $ cd rust
-
Build and install:
$ ./configure $ make && make installNote: You may need to use
sudo make installif you do not normally have permission to modify the destination directory. The install locations can be adjusted by passing a--prefixargument toconfigure. Various other options are also supported – pass--helpfor more information on them.When complete,
make installwill place several programs into/usr/local/bin:rustc, the Rust compiler, andrustdoc, the API-documentation tool. This install does not include Cargo, Rust's package manager, which you may also want to build.
Building on Windows
MSYS2 can be used to easily build Rust on Windows:
-
Grab the latest MSYS2 installer and go through the installer.
-
From the MSYS2 terminal, install the
mingw64toolchain and other required tools.# Choose one based on platform: $ pacman -S mingw-w64-i686-toolchain $ pacman -S mingw-w64-x86_64-toolchain $ pacman -S base-devel -
Run
mingw32_shell.batormingw64_shell.batfrom wherever you installed MSYS2 (i.e.C:\msys), depending on whether you want 32-bit or 64-bit Rust. -
Navigate to Rust's source code, configure and build it:
$ ./configure $ make && make install
Notes
Since the Rust compiler is written in Rust, it must be built by a precompiled "snapshot" version of itself (made in an earlier state of development). As such, source builds require a connection to the Internet, to fetch snapshots, and an OS that can execute the available snapshot binaries.
Snapshot binaries are currently built and tested on several platforms:
| Platform \ Architecture | x86 | x86_64 |
|---|---|---|
| Windows (7, 8, Server 2008 R2) | ✓ | ✓ |
| Linux (2.6.18 or later) | ✓ | ✓ |
| OSX (10.7 Lion or later) | ✓ | ✓ |
You may find that other platforms work, but these are our officially supported build environments that are most likely to work.
Rust currently needs about 1.5 GiB of RAM to build without swapping; if it hits swap, it will take a very long time to build.
There is more advice about hacking on Rust in CONTRIBUTING.md.
Getting Help
The Rust community congregates in a few places:
- Stack Overflow - Direct questions about using the language.
- users.rust-lang.org - General discussion and broader questions.
- /r/rust - News and general discussion.
Contributing
To contribute to Rust, please see CONTRIBUTING.
Rust has an IRC culture and most real-time collaboration happens in a variety of channels on Mozilla's IRC network, irc.mozilla.org. The most popular channel is #rust, a venue for general discussion about Rust, and a good place to ask for help.
License
Rust is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0), with portions covered by various BSD-like licenses.
See LICENSE-APACHE, LICENSE-MIT, and COPYRIGHT for details.