State of Swift Internals: Swift 4 & 5

on YouTube ↗49m

" summary

Shows concrete findings: compiler emits Swift Intermediate Language (SIL) then LLVM IR and assembly, with reproducible examples and code on GitHub; documents that ABI ~90% complete in Swift 4.2 and that data layout is often reordered for 64‑bit alignment (struct packing and stack allocation observed, including a mysterious double-init and copy‑out pattern); calling conventions largely follow System V so the runtime is callable from other languages; notes ownership/exclusivity in 4.2 and precise library‑evolution rules that specify what changes are ABI‑safe.

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" chapters (20)

1. 0:00Introduction
2. 2:20Outline
3. 5:08Systems Programming Language
4. 8:09Swift Intermediate Language
5. 9:45API Stability
6. 11:27Data Layouts
7. 13:56Game Spacing
8. 16:50Init
9. 18:05Read
10. 25:00Alignment
11. 28:20Structure
12. 29:33Compiler
13. 33:22Calling Convention
14. 35:33Registers
15. 37:36Swift Intermediate
16. 38:39Intermediate Swift
17. 40:25Library
18. 42:39Lifetimes
19. 46:20Swift C
20. 46:48Swift Runtime

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