When it comes to writing high-performance code, I’ve received a lot of advice over the years, and have heard a lot of qualified people express a lot of very strong opinions about what makes a…

Community Picks is a section on daily.dev where our community members share the most interesting and valuable content they've discovered online. From insightful articles to handy tools, every post is a gem curated by our dedicated coomunity. To contribute to Community Picks, you need to have at least 250 reputation points, ensuring that only active and trusted members can share their finds.

Community Picks

Writing high-performance code involves understanding which common performance tips are actually effective. The post discusses several common myths and realities regarding programming performance, including the cost of virtual function calls, the benefits of function inlining and compile-time polymorphism, and the complexities of auto-vectorization and memory usage. It emphasizes the importance of verifying performance claims through rigorous testing and the use of platform-specific optimizations.

Programming Performance Myths vs. Realities

Myth: “Virtual function calls are free/cheap”

Reality: “Reading/writing local variables is faster than reading/writing member variables”

Myth: “Auto-vectorization can match/beat explicit vectorization”

Reality: “Platform specificity is good”

<p>All those myths (in tandem with the abundance of resources) are the very reason that modern applications (and even websites!) require progressively more resources.  Optimization and understanding of performance issues were a must in the good old days (and still are in embedded, bare metal) because you simply didn’t have that much of L1-3 cache or RAM.</p>
