#llvm #mlir #ir

melior

The rustic MLIR bindings in Rust

4 releases (2 breaking)

Uses new Rust 2021

0.3.1 Sep 24, 2022
0.3.0 Sep 23, 2022
0.2.0 Sep 23, 2022
0.1.0 Jul 10, 2022

#12 in #llvm

Apache-2.0

155KB
4.5K SLoC

Melior

GitHub Action Crate License

The rustic MLIR bindings for Rust

This crate is a wrapper of the MLIR C API.

use melior::{
    Context,
    dialect,
    ir::*,
    utility::register_all_dialects,
};

let registry = dialect::Registry::new();
register_all_dialects(&registry);

let context = Context::new();
context.append_dialect_registry(&registry);
context.get_or_load_dialect("func");

let location = Location::unknown(&context);
let module = Module::new(location);

let integer_type = Type::integer(&context, 64);

let function = {
    let region = Region::new();
    let block = Block::new(&[(integer_type, location), (integer_type, location)]);

    let sum = block.append_operation(
        operation::Builder::new("arith.addi", location)
            .add_operands(&[*block.argument(0).unwrap(), *block.argument(1).unwrap()])
            .add_results(&[integer_type])
            .build(),
    );

    block.append_operation(
        operation::Builder::new("func.return", Location::unknown(&context))
            .add_operands(&[*sum.result(0).unwrap()])
            .build(),
    );

    region.append_block(block);

    operation::Builder::new("func.func", Location::unknown(&context))
        .add_attributes(&[
            (
                Identifier::new(&context, "function_type"),
                Attribute::parse(&context, "(i64, i64) -> i64").unwrap(),
            ),
            (
                Identifier::new(&context, "sym_name"),
                Attribute::parse(&context, "\"add\"").unwrap(),
            ),
        ])
        .add_regions(vec![region])
        .build()
};

module.body().append_operation(function);

assert!(module.as_operation().verify());

Goals

Melior aims to provide a simple, safe, and complete API for MLIR with a reasonably sane ownership model represented by the type system in Rust.

Install

cargo add melior

Dependencies

LLVM/MLIR 15 needs to be installed on your system. On Linux and macOS, you can install it via Homebrew.

brew install llvm@15

Documentation

On GitHub Pages.

Contribution

Contribution is welcome! But, Melior is still in the alpha stage as well as the MLIR C API. Note that the API is unstable and can have breaking changes in the future.

Technical notes

  • We always use &T for MLIR objects instead of &mut T to mitigate the intricacy of representing a loose ownership model of the MLIR C API in Rust.
  • Only UTF-8 is supported as string encoding.
    • Most string conversion between Rust and C is cached internally.

Naming conventions

  • Mlir<X> objects are named <X> if they have no destructor. Otherwise, they are named <X> for owned objects and <X>Ref for borrowed references.
  • mlir<X>Create functions are renamed as <X>::new.
  • mlir<X>Get<Y> functions are renamed as follows:
    • If the resulting objects refer to &self, they are named <X>::as_<Y>.
    • Otherwise, they are named just <X>::<Y> and may have arguments, such as position indices.

References

License

Apache 2.0

Dependencies

~0–1.6MB
~32K SLoC