--- title: Benchmarking and optimizing the Carbon compiler -... description: Chandler Carruth walks through how the Carbon compiler team benchmarks and optimizes compiler performance, using hash table optimization as a detailed case... canonical: https://daily.dev/posts/benchmarking-and-optimizing-the-carbon-compiler---chandler-carruth---ndc-toronto-2026-i4ljgsvpo twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Benchmarking and optimizing the Carbon compiler - Chandler Carruth - NDC Toronto 2026 | daily.dev og:description: Chandler Carruth walks through how the Carbon compiler team benchmarks and optimizes compiler performance, using hash table optimization as a detailed case... og:url: https://daily.dev/posts/benchmarking-and-optimizing-the-carbon-compiler---chandler-carruth---ndc-toronto-2026-i4ljgsvpo og:image: https://api.daily.dev/og/posts/I4ljgSVPo.png og:image:alt: Benchmarking and optimizing the Carbon compiler - Chandler Carruth - NDC Toronto 2026 og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Benchmarking and optimizing the Carbon compiler - Chandler Carruth - NDC Toronto 2026 **[NDC Conferences](https://daily.dev/sources/ndc)** · 63 min read · 0 upvotes · 0 comments ## Summary Chandler Carruth walks through how the Carbon compiler team benchmarks and optimizes compiler performance, using hash table optimization as a detailed case study. Key topics include: designing representative microbenchmarks using Google Benchmark with latency vs. throughput awareness, batched benchmark loops to avoid cache skew, statistical noise reduction, and building a deterministic source code generator that samples real-world identifier length distributions from LLVM. The talk reveals that Swiss table hash maps shift the performance bottleneck from probing quality to hash latency, making weaker but faster hash functions preferable. Carbon's custom hash table outperforms Abseil's by ~23% on lookup hits and nearly 2x on insertion sequences. The compiler benchmark infrastructure generates synthetic Carbon/C++ source files parameterized by line count and code shape, achieving goals of 10M lines/sec for lexing and 1M lines/sec for semantic checking on Apple M4 hardware. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Writing a Fast Compiler](https://daily.dev/posts/writing-a-fast-compiler-5hnqshf7f) · Lobsters · 0 upvotes · 0 comments - [One Line x86 Change To GCC Compiler Nets \+12% Benchmark Win For Modern Intel/AMD CPUs](https://daily.dev/posts/one-line-x86-change-to-gcc-compiler-nets-12-benchmark-win-for-modern-intel-amd-cpus-hm9xklk3r) · Phoronix · 1 upvotes · 0 comments - [Leaving performance on the table](https://daily.dev/posts/leaving-performance-on-the-table-z6ieh43af) · Farid Zakaria’s Blog · 0 upvotes · 0 comments - [How We Beat HotSpot Performance \(By Cheating, But Not Like That\)](https://daily.dev/posts/how-we-beat-hotspot-performance-by-cheating-but-not-like-that--cmfnlzlgr) · Foojay.io · 1 upvotes · 0 comments --- Tags: [#c++](https://daily.dev/tags/c++), [#compiler](https://daily.dev/tags/compiler) [View this post on daily.dev](https://daily.dev/posts/benchmarking-and-optimizing-the-carbon-compiler---chandler-carruth---ndc-toronto-2026-i4ljgsvpo) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Benchmarking and optimizing the Carbon compiler - Chandler Carruth - NDC Toronto 2026","url":"https://daily.dev/posts/benchmarking-and-optimizing-the-carbon-compiler---chandler-carruth---ndc-toronto-2026-i4ljgsvpo","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/benchmarking-and-optimizing-the-carbon-compiler---chandler-carruth---ndc-toronto-2026-i4ljgsvpo"},"datePublished":"2026-07-23T11:02:41.283Z","dateModified":"2026-07-23T12:49:53.802Z","description":"Chandler Carruth walks through how the Carbon compiler team benchmarks and optimizes compiler performance, using hash table optimization as a detailed case...","image":"https://i.ytimg.com/vi/hN6KcAKfTN0/sddefault.jpg","thumbnailUrl":"https://i.ytimg.com/vi/hN6KcAKfTN0/sddefault.jpg","isAccessibleForFree":true,"articleSection":"NDC Conferences","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"NDC Conferences","logo":"https://media.daily.dev/image/upload/s--SiIyojEj--/f_auto/v1748760369/logos/ndc","url":"https://daily.dev/sources/ndc"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/benchmarking-and-optimizing-the-carbon-compiler---chandler-carruth---ndc-toronto-2026-i4ljgsvpo","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"c++,compiler","timeRequired":"PT63M","video":{"@type":"VideoObject","name":"Benchmarking and optimizing the Carbon compiler - Chandler Carruth - NDC Toronto 2026","description":"Chandler Carruth walks through how the Carbon compiler team benchmarks and optimizes compiler performance, using hash table optimization as a detailed case...","thumbnailUrl":"https://i.ytimg.com/vi/hN6KcAKfTN0/sddefault.jpg","uploadDate":"2026-07-23T11:02:41.283Z","duration":"PT63M","url":"https://api.daily.dev/r/I4ljgSVPo","embedUrl":"https://www.youtube.com/embed/hN6KcAKfTN0"}} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"NDC Conferences","item":"https://daily.dev/sources/ndc"},{"@type":"ListItem","position":3,"name":"Benchmarking and optimizing the Carbon compiler - Chandler Carruth - NDC Toronto 2026"}]} ```