The author dramatically improved the debug build speed of their C++ project, achieving up to 100x faster execution. The primary culprit was excessive logging, specifically the use of a logging library with a slow formatting implementation, exacerbated by unnecessary string formatting even when logs weren't being written. By switching to a faster logging library (spdlog), deferring string formatting until after log level checks, and optimizing other minor inefficiencies, they brought their debug build performance to a usable level, allowing for significantly faster iteration times during development.
Wild is a new, fast linker for Linux designed for significantly faster linking than traditional linkers like ld. It leverages parallelization and a novel approach to symbol resolution, claiming to be up to 4x faster for large projects like Firefox and Chromium. Wild aims to be drop-in compatible with existing workflows, requiring no changes to source code or build systems. It also offers advanced features like incremental linking and link-time optimization, further enhancing development speed. While still under development, Wild shows promise as a powerful tool to accelerate the build process for complex C++ projects.
HN commenters generally praised Wild's speed and innovative approach to linking. Several expressed excitement about its potential to significantly improve build times, particularly for large C++ projects. Some questioned its compatibility and maturity, noting it's still early in development. A few users shared their experiences testing Wild, reporting positive results but also mentioning some limitations and areas for improvement, like debugging support and handling of complex linking scenarios. There was also discussion about the technical details behind Wild's performance gains, including its use of parallelization and caching. A few commenters drew comparisons to other linkers like mold and lld, discussing their relative strengths and weaknesses.
Summary of Comments ( 16 )
https://news.ycombinator.com/item?id=43087482
Commenters on Hacker News largely praised the author's approach to optimizing debug builds, emphasizing the significant impact build times have on developer productivity. Several highlighted the importance of the described techniques, like using link-time optimization (LTO) and profile-guided optimization (PGO) even in debug builds, challenging the common trade-off between debuggability and speed. Some shared similar experiences and alternative optimization strategies, such as using pre-compiled headers (PCH) and unity builds, or employing tools like ccache. A few also pointed out potential downsides, like increased memory usage with LTO, and the need to balance optimization with the ability to effectively debug. The overall sentiment was that the author's detailed breakdown offered valuable insights and practical solutions for a common developer pain point.
The Hacker News post "Making my debug build run 100x faster so that it is finally usable" generated a lively discussion with several compelling comments. Many commenters shared their own experiences and insights related to debug build performance.
A recurring theme was the importance of build optimization and the significant impact it can have on developer productivity. One commenter highlighted the frustration of slow debug builds, stating that it disrupts the flow of development and makes debugging a painful process. They praised the author of the original article for sharing their optimization techniques, emphasizing the value of such knowledge in the developer community.
Several commenters discussed specific strategies for improving debug build times. Suggestions included disabling link-time optimization (LTO), using pre-compiled headers (PCH), and minimizing the use of debug symbols. One commenter pointed out that the choice of build system can also significantly affect build times, with some systems being inherently faster than others. Another commenter shared their experience with incremental builds, noting that they can dramatically reduce build times when implemented correctly.
The discussion also touched upon the trade-offs between debug build speed and debugging capabilities. While faster builds are generally desirable, some commenters cautioned against sacrificing essential debugging information for the sake of speed. They argued that a balance must be struck between build performance and the ability to effectively debug code. One commenter suggested using different build configurations for different stages of development, with faster builds optimized for rapid iteration and slower, more comprehensive builds reserved for in-depth debugging.
Some commenters expressed skepticism about the author's claim of a 100x speedup, suggesting that such a dramatic improvement might be specific to the author's particular project or environment. They encouraged others to try the author's techniques and share their own results, emphasizing the importance of empirical evidence.
Overall, the comments on the Hacker News post reflect a shared concern among developers about the performance of debug builds and a desire for effective strategies to improve them. The discussion provided valuable insights into various optimization techniques and sparked a productive exchange of ideas and experiences.