mirl

mirl is the intermediate representation and code generator of the mach toolchain. It is a library and a program written in mach. A front end builds mirl IR through the builder API, or writes it as text, and mirl optimises it, legalises it for a target, selects instructions, allocates registers, lays out frames, applies calling conventions and produces debug information.

Place in the toolchain

mach -> mirl -> masc -> mink

• mach is the language front end. It hands mirl the IR.
• mirl is the IR and code generation. It hands masc assembly in masc's model.
• masc is the assembler. It owns instruction sets, registers and encodings, and hands mink objects.
• mink is the linker. It owns object formats, architecture identity and relocations.

mirl never reaches past masc. A front end asks mirl for data layout and calling conventions and never computes either itself.

Parts

• mirl.ir holds the types, values, instructions and modules, and mirl.ir.text the text form. The IR is in SSA form with block parameters, and every opcode's typing rule and effects live in one table.
• mirl.build is the builder and mirl.verify the verifier.
• mirl.target is the target record. A target declares its capabilities, data layout and calling conventions as data, and the pipeline is chosen from those declarations. Each family sits in mirl.target.<family>, with the register family's members, such as RISC-V, one level below it.
• mirl.pass holds the pass contract and schedule, mirl.opt the optimisation passes and mirl.legal legalisation.
• mirl.machine is the machine form below the IR, with selection, register allocation, frames, block layout and emission as its children.
• mirl.debug produces debug information from the IR's debug tables, and mirl.ct preserves and validates secrecy and constant time.
• mirl.structure turns any control flow graph into structured regions for the SPIR-V (mirl.target.spirv) and WebAssembly (mirl.target.wasm) families.

The IR is specified in doc/ir.md.

Building

mirl builds with mach 6.10.1 or later.

mach dep pull .
mach build .
mach test . -a '*'