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Passes and Implementation

This section focuses on custom LLVM passes, detailing how to create them effectively. If you encounter any difficulties, feel free to reach out via email at info@compilersutra.com.

Tutorials and Resources​

  1. Creating an LLVM Pass to Count Functions in C/C++ Code
    Learn how to develop a custom LLVM pass that counts the number of functions in a C/C++ codebase. This tutorial provides step-by-step guidance, complete with examples and best practices for implementation. Ensure you follow along with the setup instructions to avoid any issues.

  2. Creating an LLVM Pass to Count Instructions in the Pass
    Discover how to implement an LLVM pass that counts the number of instructions executed in the analyzed code. This guide includes practical examples, configuration steps, and tips for effective usage.

📘 LLVM Documentation

Welcome to the LLVM Documentation section! This guide is designed to provide foundational knowledge, setup instructions, and insights into LLVM's capabilities.

🛠️ Getting Started with LLVM​

  • What is LLVM?
    Discover the essentials of LLVM, its role in compiler development, and why it’s a powerful choice for building modular and reusable compiler frameworks.

  • Why LLVM?
    Understand the key reasons behind LLVM's popularity, from its flexibility and optimizations to its wide range of applications in compilers, tools, and beyond.

🚀 Building and Deploying​

  • Build Guide
    Step-by-step instructions to build LLVM from source, covering prerequisites, configuration, and troubleshooting tips to ensure a smooth setup.

  • Learning Compilers
    Learn how to compiler works and your LLVM-based projects and documentation, with tips options and best practices..

🎉 Pass​

What Are LLVM Passes?​

LLVM passes are modular components that analyze and transform the Intermediate Representation (IR) of code within the LLVM framework. They are crucial for optimization, code analysis, and generation.

Categories of Passes​

  1. Analysis Passes

    • Provide insights into the code without modifying it.
    • Examples: Loop Analysis, Alias Analysis.

  2. Transformation Passes

    • Modify the IR to optimize or restructure the code.
    • Examples: Dead Code Elimination, Inlining.

  3. Utility Passes

    • Assist other passes by providing useful utilities.
    • Examples: Verifier Pass, Print Module Pass.

Commonly Used Passes​

  • Function Inlining: Replaces function calls with the function’s body to reduce call overhead.
  • Dead Code Elimination: Removes code that does not affect program results.
  • Loop Unrolling: Expands loops to decrease loop overhead and increase performance.

How to Work with Passes​

  1. Enable Passes: Use opt command-line tool to apply passes to an IR file. 
    opt -passes=<pass-name> input.ll -o output.ll


📚 Overview​

This documentation is structured to support both newcomers and seasoned developers working with LLVM. Start with the foundational concepts in What is LLVM?, and progress through setup, deployment, and advanced Markdown features.

🚀 Let's Dive In!​

Select a document to begin your journey in LLVM, or start from the basics to build a solid understanding of this powerful infrastructure.