d82ebcc102
* x64: Enable load-coalescing for SSE/AVX instructions This commit unlocks the ability to fold loads into operands of SSE and AVX instructions. This is beneficial for both function size when it happens in addition to being able to reduce register pressure. Previously this was not done because most SSE instructions require memory to be aligned. AVX instructions, however, do not have alignment requirements. The solution implemented here is one recommended by Chris which is to add a new `XmmMemAligned` newtype wrapper around `XmmMem`. All SSE instructions are now annotated as requiring an `XmmMemAligned` operand except for a new new instruction styles used specifically for instructions that don't require alignment (e.g. `movdqu`, `*sd`, and `*ss` instructions). All existing instruction helpers continue to take `XmmMem`, however. This way if an AVX lowering is chosen it can be used as-is. If an SSE lowering is chosen, however, then an automatic conversion from `XmmMem` to `XmmMemAligned` kicks in. This automatic conversion only fails for unaligned addresses in which case a load instruction is emitted and the operand becomes a temporary register instead. A number of prior `Xmm` arguments have now been converted to `XmmMem` as well. One change from this commit is that loading an unaligned operand for an SSE instruction previously would use the "correct type" of load, e.g. `movups` for f32x4 or `movup` for f64x2, but now the loading happens in a context without type information so the `movdqu` instruction is generated. According to [this stack overflow question][question] it looks like modern processors won't penalize this "wrong" choice of type when the operand is then used for f32 or f64 oriented instructions. Finally this commit improves some reuse of logic in the `put_in_*_mem*` helper to share code with `sinkable_load` and avoid duplication. With this in place some various ISLE rules have been updated as well. In the tests it can be seen that AVX-instructions are now automatically load-coalesced and use memory operands in a few cases. [question]: https://stackoverflow.com/questions/40854819/is-there-any-situation-where-using-movdqu-and-movupd-is-better-than-movups * Fix tests * Fix move-and-extend to be unaligned These don't have alignment requirements like other xmm instructions as well. Additionally add some ISA tests to ensure that their output is tested. * Review comments
wasmtime
A standalone runtime for WebAssembly
A Bytecode Alliance project
Guide | Contributing | Website | Chat
Installation
The Wasmtime CLI can be installed on Linux and macOS (locally) with a small install script:
curl https://wasmtime.dev/install.sh -sSf | bash
Windows or otherwise interested users can download installers and binaries directly from the GitHub Releases page.
Example
If you've got the Rust compiler installed then you can take some Rust source code:
fn main() {
println!("Hello, world!");
}
and compile/run it with:
$ rustup target add wasm32-wasi
$ rustc hello.rs --target wasm32-wasi
$ wasmtime hello.wasm
Hello, world!
Features
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Fast. Wasmtime is built on the optimizing Cranelift code generator to quickly generate high-quality machine code either at runtime or ahead-of-time. Wasmtime is optimized for efficient instantiation, low-overhead calls between the embedder and wasm, and scalability of concurrent instances.
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Secure. Wasmtime's development is strongly focused on correctness and security. Building on top of Rust's runtime safety guarantees, each Wasmtime feature goes through careful review and consideration via an RFC process. Once features are designed and implemented, they undergo 24/7 fuzzing donated by Google's OSS Fuzz. As features stabilize they become part of a release, and when things go wrong we have a well-defined security policy in place to quickly mitigate and patch any issues. We follow best practices for defense-in-depth and integrate protections and mitigations for issues like Spectre. Finally, we're working to push the state-of-the-art by collaborating with academic researchers to formally verify critical parts of Wasmtime and Cranelift.
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Configurable. Wasmtime uses sensible defaults, but can also be configured to provide more fine-grained control over things like CPU and memory consumption. Whether you want to run Wasmtime in a tiny environment or on massive servers with many concurrent instances, we've got you covered.
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WASI. Wasmtime supports a rich set of APIs for interacting with the host environment through the WASI standard.
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Standards Compliant. Wasmtime passes the official WebAssembly test suite, implements the official C API of wasm, and implements future proposals to WebAssembly as well. Wasmtime developers are intimately engaged with the WebAssembly standards process all along the way too.
Language Support
You can use Wasmtime from a variety of different languages through embeddings of the implementation.
Languages supported by the Bytecode Alliance:
- Rust - the
wasmtimecrate - C - the
wasm.h,wasi.h, andwasmtime.hheaders, CMake orwasmtimeConan package - C++ - the
wasmtime-cpprepository or usewasmtime-cppConan package - Python - the
wasmtimePyPI package - .NET - the
WasmtimeNuGet package - Go - the
wasmtime-gorepository - Ruby - the
wasmtimegem
Languages supported by the community:
- Elixir - the
wasmexhex package
Documentation
📚 Read the Wasmtime guide here! 📚
The wasmtime guide is the best starting point to learn about what Wasmtime can do for you or help answer your questions about Wasmtime. If you're curious in contributing to Wasmtime, it can also help you do that!
It's Wasmtime.