LLVM recently added a new attribute, dereferenceable: http://reviews.llvm.org/D4449 >This patch adds a dereferencable attribute. In some sense, this is a companion to the nonnull attribute, but specifies that the pointer is known to be dereferencable in the same sense as a pointer generated by alloca is known to be dereferencable. With rust, everywhere that we previously marked `nonnull` we can actually mark as `dereferenceable` (which implies nonnull) since we know the size. That is, except for one case: when generating calls for TyVisitor. It seems like we haven't substituted the self type (so we have `ty_param`) and just treat it as an opaque pointer so I just left that bit as nonnull. With this, LLVM can for example hoist a load out of a loop where it previously couldn't: ```Rust pub fn baz(c: &uint, n: uint) -> uint { let mut res = 0; for i in range(0, n) { if i > 0 { res += *c * i; } } res } ``` Before: ```llvm define i64 @baz(i64* noalias nocapture nonnull readonly, i64) unnamed_addr #0 { entry-block: br label %for_loopback.outer for_loopback.outer: ; preds = %then-block-33-, %entry-block %.ph = phi i64 [ %.lcssa, %then-block-33- ], [ 0, %entry-block ] %res.0.ph = phi i64 [ %8, %then-block-33- ], [ 0, %entry-block ] br label %for_loopback for_exit: ; preds = %for_loopback %res.0.ph.lcssa = phi i64 [ %res.0.ph, %for_loopback ] ret i64 %res.0.ph.lcssa for_loopback: ; preds = %for_loopback.outer, %for_body %2 = phi i64 [ %4, %for_body ], [ %.ph, %for_loopback.outer ] %3 = icmp ult i64 %2, %1 br i1 %3, label %for_body, label %for_exit for_body: ; preds = %for_loopback %4 = add i64 %2, 1 %5 = icmp eq i64 %2, 0 br i1 %5, label %for_loopback, label %then-block-33- then-block-33-: ; preds = %for_body %.lcssa = phi i64 [ %4, %for_body ] %.lcssa15 = phi i64 [ %2, %for_body ] %6 = load i64* %0, align 8 ; <------- this load %7 = mul i64 %6, %.lcssa15 %8 = add i64 %7, %res.0.ph br label %for_loopback.outer } ``` After: ```llvm define i64 @baz(i64* noalias nocapture readonly dereferenceable(8), i64) unnamed_addr #0 { entry-block: %2 = load i64* %0, align 8 ; <------- load once instead br label %for_loopback.outer for_loopback.outer: ; preds = %then-block-33-, %entry-block %.ph = phi i64 [ %.lcssa, %then-block-33- ], [ 0, %entry-block ] %res.0.ph = phi i64 [ %8, %then-block-33- ], [ 0, %entry-block ] br label %for_loopback for_exit: ; preds = %for_loopback %res.0.ph.lcssa = phi i64 [ %res.0.ph, %for_loopback ] ret i64 %res.0.ph.lcssa for_loopback: ; preds = %for_loopback.outer, %for_body %3 = phi i64 [ %5, %for_body ], [ %.ph, %for_loopback.outer ] %4 = icmp ult i64 %3, %1 br i1 %4, label %for_body, label %for_exit for_body: ; preds = %for_loopback %5 = add i64 %3, 1 %6 = icmp eq i64 %3, 0 br i1 %6, label %for_loopback, label %then-block-33- then-block-33-: ; preds = %for_body %.lcssa = phi i64 [ %5, %for_body ] %.lcssa15 = phi i64 [ %3, %for_body ] %7 = mul i64 %2, %.lcssa15 %8 = add i64 %7, %res.0.ph br label %for_loopback.outer } ``` |
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| .mailmap | ||
| .travis.yml | ||
| AUTHORS.txt | ||
| configure | ||
| CONTRIBUTING.md | ||
| COPYRIGHT | ||
| LICENSE-APACHE | ||
| LICENSE-MIT | ||
| Makefile.in | ||
| README.md | ||
| RELEASES.txt | ||
The Rust Programming Language
This is a compiler for Rust, including standard libraries, tools and documentation.
Quick Start
- Download a binary installer for your platform.
- Read the tutorial.
- Enjoy!
Note: Windows users can read the detailed getting started notes on the wiki.
Building from Source
-
Make sure you have installed the dependencies:
g++4.7 orclang++3.xpython2.6 or later (but not 3.x)perl5.0 or later- GNU
make3.81 or later curlgit
-
Download and build Rust:
You can either download a tarball or build directly from the repo.
To build from the tarball do:
$ curl -O http://static.rust-lang.org/dist/rust-nightly.tar.gz $ tar -xzf rust-nightly.tar.gz $ cd rust-nightlyOr to build from the repo do:
$ git clone https://github.com/rust-lang/rust.git $ cd rustNow that you have Rust's source code, you can configure and build it:
$ ./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. -
Read the tutorial.
-
Enjoy!
Building on Windows
To easily build on windows we can use MSYS2:
-
Grab the latest MSYS2 installer and go through the installer.
-
Now from the MSYS2 terminal we want to install the mingw64 toolchain and the other tools we need.
$ pacman -S mingw-w64-i686-toolchain $ pacman -S base-devel -
With that now start
mingw32_shell.batfrom where you installed MSYS2 (i.e.C:\msys). -
From there just navigate to where you have Rust's source code, configure and build it:
$ ./configure --build=i686-pc-mingw32 $ 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:
- Windows (7, 8, Server 2008 R2), x86 only
- Linux (2.6.18 or later, various distributions), x86 and x86-64
- OSX 10.7 (Lion) or greater, x86 and x86-64
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 a lot more documentation in the wiki.
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.