Files
wasmtime/lib/frontend/src/lib.rs
Dan Gohman c7655c4928 Add minimal README.md files to published crates.
This will put descriptions on the packages' crates.io pages.
2018-02-21 20:50:03 -08:00

153 lines
4.6 KiB
Rust

//! Cretonne IL builder library.
//!
//! Provides a straightforward way to create a Cretonne IL function and fill it with instructions
//! translated from another language. Contains an SSA construction module that lets you translate
//! your non-SSA variables into SSA Cretonne IL values via `use_var` and `def_var` calls.
//!
//! To get started, create an [`IlBuilder`](struct.ILBuilder.html) and pass it as an argument
//! to a [`FunctionBuilder`](struct.FunctionBuilder.html).
//!
//! # Example
//!
//! Here is a pseudo-program we want to transform into Cretonne IL:
//!
//! ```cton
//! function(x) {
//! x, y, z : i32
//! block0:
//! y = 2;
//! z = x + y;
//! jump block1
//! block1:
//! z = z + y;
//! brnz y, block2;
//! z = z - x;
//! return y
//! block2:
//! y = y - x
//! jump block1
//! }
//! ```
//!
//! Here is how you build the corresponding Cretonne IL function using `ILBuilder`:
//!
//! ```rust
//! extern crate cretonne;
//! extern crate cton_frontend;
//!
//! use cretonne::entity::EntityRef;
//! use cretonne::ir::{ExternalName, CallConv, Function, Signature, AbiParam, InstBuilder};
//! use cretonne::ir::types::*;
//! use cretonne::settings;
//! use cton_frontend::{ILBuilder, FunctionBuilder};
//! use cretonne::verifier::verify_function;
//! use std::u32;
//!
//! // An opaque reference to variable.
//! #[derive(Copy, Clone, PartialEq, Eq, Debug)]
//! pub struct Variable(u32);
//! impl EntityRef for Variable {
//! fn new(index: usize) -> Self {
//! assert!(index < (u32::MAX as usize));
//! Variable(index as u32)
//! }
//!
//! fn index(self) -> usize {
//! self.0 as usize
//! }
//! }
//!
//! fn main() {
//! let mut sig = Signature::new(CallConv::Native);
//! sig.returns.push(AbiParam::new(I32));
//! sig.params.push(AbiParam::new(I32));
//! let mut il_builder = ILBuilder::<Variable>::new();
//! let mut func = Function::with_name_signature(ExternalName::user(0, 0), sig);
//! {
//! let mut builder = FunctionBuilder::<Variable>::new(&mut func, &mut il_builder);
//!
//! let block0 = builder.create_ebb();
//! let block1 = builder.create_ebb();
//! let block2 = builder.create_ebb();
//! let x = Variable(0);
//! let y = Variable(1);
//! let z = Variable(2);
//! builder.declare_var(x, I32);
//! builder.declare_var(y, I32);
//! builder.declare_var(z, I32);
//! builder.append_ebb_params_for_function_params(block0);
//!
//! builder.switch_to_block(block0);
//! builder.seal_block(block0);
//! {
//! let tmp = builder.ebb_params(block0)[0]; // the first function parameter
//! builder.def_var(x, tmp);
//! }
//! {
//! let tmp = builder.ins().iconst(I32, 2);
//! builder.def_var(y, tmp);
//! }
//! {
//! let arg1 = builder.use_var(x);
//! let arg2 = builder.use_var(y);
//! let tmp = builder.ins().iadd(arg1, arg2);
//! builder.def_var(z, tmp);
//! }
//! builder.ins().jump(block1, &[]);
//!
//! builder.switch_to_block(block1);
//! {
//! let arg1 = builder.use_var(y);
//! let arg2 = builder.use_var(z);
//! let tmp = builder.ins().iadd(arg1, arg2);
//! builder.def_var(z, tmp);
//! }
//! {
//! let arg = builder.use_var(y);
//! builder.ins().brnz(arg, block2, &[]);
//! }
//! {
//! let arg1 = builder.use_var(z);
//! let arg2 = builder.use_var(x);
//! let tmp = builder.ins().isub(arg1, arg2);
//! builder.def_var(z, tmp);
//! }
//! {
//! let arg = builder.use_var(y);
//! builder.ins().return_(&[arg]);
//! }
//!
//! builder.switch_to_block(block2);
//! builder.seal_block(block2);
//!
//! {
//! let arg1 = builder.use_var(y);
//! let arg2 = builder.use_var(x);
//! let tmp = builder.ins().isub(arg1, arg2);
//! builder.def_var(y, tmp);
//! }
//! builder.ins().jump(block1, &[]);
//! builder.seal_block(block1);
//!
//! builder.finalize();
//! }
//!
//! let flags = settings::Flags::new(&settings::builder());
//! let res = verify_function(&func, &flags);
//! println!("{}", func.display(None));
//! match res {
//! Ok(_) => {}
//! Err(err) => panic!("{}", err),
//! }
//! }
//! ```
#![deny(missing_docs)]
extern crate cretonne;
pub use frontend::{ILBuilder, FunctionBuilder};
mod frontend;
mod ssa;