df923f18ca
* aarch64: constant generation cleanup Add support for MOVZ and MOVN generation via ISLE. Handle f32const, f64const, and nop instructions via ISLE. No longer call Inst::gen_constant from lower.rs. * riscv64: constant generation cleanup Handle f32const, f64const, and nop instructions via ISLE. * s390x: constant generation cleanup Fix rule priorities for "imm" term. Only handle 32-bit stack offsets; no longer use load_constant64. * x64: constant generation cleanup No longer call Inst::gen_constant from lower.rs or abi.rs. * Refactor LowerBackend::lower to return InstOutput No longer write to the per-insn output registers; instead, return an InstOutput vector of temp registers holding the outputs. This will allow calling LowerBackend::lower multiple times for the same instruction, e.g. to rematerialize constants. When emitting the primary copy of the instruction during lowering, writing to the per-insn registers is now done in lower_clif_block. As a result, the ISLE lower_common routine is no longer needed. In addition, the InsnOutput type and all code related to it can be removed as well. * Refactor IsleContext to hold a LowerBackend reference Remove the "triple", "flags", and "isa_flags" fields that are copied from LowerBackend to each IsleContext, and instead just hold a reference to LowerBackend in IsleContext. This will allow calling LowerBackend::lower from within callbacks in src/machinst/isle.rs, e.g. to rematerialize constants. To avoid having to pass LowerBackend references through multiple functions, eliminate the lower_insn_to_regs subroutines in those targets that still have them, and just inline into the main lower routine. This also eliminates lower_inst.rs on aarch64 and riscv64. Replace all accesses to the removed IsleContext fields by going through the LowerBackend reference. * Remove MachInst::gen_constant This addresses the problem described in issue https://github.com/bytecodealliance/wasmtime/issues/4426 that targets currently have to duplicate code to emit constants between the ISLE logic and the gen_constant callback. After the various cleanups in earlier patches in this series, the only remaining user of get_constant is put_value_in_regs in Lower. This can now be removed, and instead constant rematerialization can be performed in the put_in_regs ISLE callback by simply directly calling LowerBackend::lower on the instruction defining the constant (using a different output register). Since the check for egraph mode is now no longer performed in put_value_in_regs, the Lower::flags member becomes obsolete. Care needs to be taken that other calls directly to the Lower::put_value_in_regs routine now handle the fact that no more rematerialization is performed. All such calls in target code already historically handle constants themselves. The remaining call site in the ISLE gen_call_common helper can be redirected to the ISLE put_in_regs callback. The existing target implementations of gen_constant are then unused and can be removed. (In some target there may still be further opportunities to remove duplication between ISLE and some local Rust code - this can be left to future patches.)
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 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
-
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.
-
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.
-
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.
-
WASI. Wasmtime supports a rich set of APIs for interacting with the host environment through the WASI standard.
-
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:
- 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
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.