What Every Programmer Should Know about How CPUs Work • Matt Godbolt • GOTO 2024

Matt Godbolt explains how modern CPU features like caches and branch prediction work, and how compilers optimize code to leverage them.

This presentation was recorded at GOTO Chicago 2024. #GOTOcon #GOTOchgo gotochgo.com Matt Godbolt - Low-level Latency Geek @MattGodbolt RESOURCES bsky.app/profile/matt.godbolt.org xania.org github.com/mattgodbolt linkedin.com/in/godbolt twitter.com/mattgodbolt godbolt.org ABSTRACT When programming these days it’s easy to forget the many layers of abstractions between what you type and what the computer you run your code on is actually doing. In this talk, Matt will describe some of the performance features of modern CPUs and explain how your code is already benefiting from them. We’ll look at real-world server performance, the tooling available to measure their impact, and how compilers are often already doing the right thing for us. By the end of the talk you’ll appreciate the amazing work of chip designers and compiler authors, but you’ll also know how to diagnose when things go awry, and what to do about it. [...] TIMECODES 00:00 Intro 00:25 What to get out of this talk 01:13 A modern CPU pipeline 11:47 Branch prediction 21:27 Demo 26:15 Execution 28:56 Demo 34:53 Can the compiler save us? 35:08 Demo 36:46 Memory 37:52 Results 40:11 Top-down analysis 41:12 Perf 42:06 Conclusion 43:11 Outro Download slides and read the full abstract here: gotochgo.com/2024/sessions/3281 RECOMMENDED BOOKS Bjarne Stroustrup • Programming: Principles and Practice Using C++ • amzn.to/3Tya5G6 Bjarne Stroustrup • Tour of C++ • amzn.to/47w28Hd Bjarne Stroustrup • The C++ Programming Language • amzn.to/4ebJwyU John Horton • Beginning C++ Game Programming • amzn.to/3B8fvBd bsky.app/profile/gotocon.com twitter.com/GOTOcon linkedin.com/company/goto- instagram.com/goto_con facebook.com/GOTOConferences #CPU #CPUPipeline #HowCPUsWork #ChipDesign #x86 #x86ASM #Compiler #BranchPrediction #BloomFilter #SMT #CacheCoherency #Cache #SIMD #kcachegrind #uICA #MattGodbolt CHANNEL MEMBERSHIP BONUS Join this channel to get early access to videos & other perks: youtube.com/channel/UCs_tLP3AiwYKwdUHpltJPuA/join Looking for a unique learning experience? Attend the next GOTO conference near you! Get your ticket at gotopia.tech Sign up for updates and specials at gotopia.tech/newsletter SUBSCRIBE TO OUR CHANNEL - new videos posted almost daily. youtube.com/user/GotoConferences/?sub_confirmation=1