Part 2. Swift Compiler Internals. LLVM

LLVM (Low-Level Virtual Machine) is a widely used compiler infrastructure project designed for compiling high-level programming languages to machine code. Its modular design and extensive toolset make it a popular choice for compiler developers and programming language enthusiasts alike. This article aims to provide a detailed overview of LLVM, its architecture, components, and its significance in the realm of modern compiler technology.

What is LLVM?

LLVM is an open-source project initially developed at the University of Illinois at Urbana-Champaign by Chris Lattner in the early 2000s. It serves as both a compiler infrastructure and a set of reusable libraries for building compilers, optimizers, and runtime environments. Unlike traditional compilers that translate source code directly to machine code, LLVM adopts an intermediate representation (IR) approach. This IR, known as LLVM IR, is designed to be platform-independent, facilitating optimization and code generation for various target architectures.

Architecture

The LLVM compiler infrastructure comprises several key components, each playing a vital role in the compilation process.

1. Frontend

The frontend is responsible for translating source code written in high-level…