性能优化 之 无分支编程 Branchless Programming by 彭于斌（ @archibate ） 两种代码写法：分支 vs 三目运算符 两种使用方式：排序 vs 不排序 测试结果（均为 gcc -O3 ） 测试结果可视化 图表比较：分支 vs 无分支 分支 无分支 0 0.01 0.02 0.03 耗时（越低越好） 乱序 有序 • 传统的分支方法实现的

as embedded devices, IOS, Android, etc. It is an inevitable choice for our business to choose a language that can support multiple platforms. Share Logic 利用 Rust 重塑移动应用开发 Keystone App is a mobile application image / chart Rust FFI Rust FFI (Foreign Function Interface) refers to the ability of Rust programming language to interface with code written in other languages, typically C or C++. FFI allows Rust to languages. - JNI JNI is an interface that allows Java to interact with code written in another language. Motivation for JNI is code reusability and performance. WIth JNI, you can reuse existing/legacy

to free that? Enabling two or more disparate entities to work together.Why interoperability? No language or platform is good for everything. Fast inner loop Makes UX easy Has tooling for workload 2002, 2005 JVM – Java Native Access (JNA) – 2007 Go – cgo – permit C in the .go source file – 2009 Swift – share a runtime and be like C – 2014There is no one approach. Make it suck less by recognizing that later.What assumptions are being made? void get_size(size_t dev, long* size); Non-C/C++ language. Caller of get_size(). C/C++ binary. Provides get_size(). gcc and clang, sizeof(long) == sizeof(size_t)

oExtending with plugins oDebugging JavaScript Why are we here? How did NativeScript come to be? Swift/Obj-C Java .NET We ❤ Web. But… We need: • Better offline support • Access to all device APIs

abstract software entity, and accidental tasks, the representation of the abstract entities in programming languages and the mapping of these onto machine languages within space and speed constraints have made the accidental tasks inordinately hard, such as severe hardware constraints, awkward programming languages, lack of machine time. How much of what software engineers now do is still devoted difficulties.”Solutions to Accidental Difficulties • High-level languages • The most a high-level language can do is to furnish all the constructs the programmer imagines in the abstract program • Time-sharing

Background ERC Project "RustBelt" 2015-2021 Unlike C/C++, Rust is a safe language But, like C/C++, Rust is also an unsafe language There are guaranteed memory safety, thread safety, ... There are plenty Foundations of the Rust Programming Language. In POPL 2018: ACM SIGPLAN Symposium on Principles of Programming Languages Ralf Jung. Understanding and Evolving the Rust Programming Language. PhD dissertation Dissertation Award Recipient of the 2021 Otto Hahn Medal Ralf Jung Assistant professor, Institute for Programming Languages and Systems, ETH Zürich RustBelt Project Background Iris: A Higher-Order Concurrent

containerd runnc+Nabla OCI Solution OCI Compa tible Dedicated Docker Image Impleme ntation Language Open source Hot plug Direct access to HW Required Hyperviso rs Backed by Runc Yes Yes Golang common virtualization components which implements a Rust-based VMM. • Written in Rust: Memory-safe language • Secure: Minimal hardware emulation • Flexible: Easy to customize to fit various network, storage New language with a focus on correctness and performance • Compiled to native code offering performance similar to C • Memory management without garbage collection • Designed for systems programming Rust

memory • One test case panics, crashes all the other AT jobs • High maintenance due to programming language 大公司 API 测试的需求 软件测试工具 • 模拟数据规则 • 自动化测试 • Use rust to compile wasm and send to wasm mock memory • A test suite panic will not implicate the others • Can be compiled from many programming language • Store wasm files prevent maintenance issues API 测试 - Wasm Mock Server 用 rust, 好处多

 Recently, focus on infrastructure of Cloud/Edge Computing, AI, IoT, Programming Languages & Runtimes, Network, Virtualization, RISC-V, EDA, 5G/6G… Who Am I Source: https://sel4.systems/About/seL4-whitepaper.pdf I. Background  Capability Distribution Language tools for seL4 https://github.com/seL4/capdl CapDL I. Background  https://sel4

now Cryptape Rust My work experience • Strongly interested in programming languages implementation • My solutions to EOPL My experience • 2014 ~ 2018 Some small 年写一本编程语言实现的书 Crafting Interpreters • Essentials of Programming Languages • rui314/9cc: A Small C Compiler Great resources for programming languages Thank you ！