This week on the newsletter: "How not to mandate device-based age assurance"
https://educatedguesswork.org/posts/device-based-age-assurance/
In this post, we examine a number of enacted or proposed requirements for device-based age assurance and some of the ways they can go wrong.
Now up on the newsletter: Let's build a tool-using agent
In this post, I walk through in some detail how AI agent tool calling works, including digging into the inputs and outputs of the LLM before they get translated into a coherent-looking JS API.
Now up on the newsletter: Now up on the newsletter. "I automatically generated minutes for five years of IETF meetings (using AI)"
Now up on the newsletter, the final post in my series on memory management: Understanding Memory Management, Part 7: Advanced Garbage Collection
@hovav @pervognsen
Firefox on Linux x86-64 uses the gsbase for rlbox library sandboxing [1] because we got a pretty nice perf boost --- eliminates roughly 75% of wasm's overhead on some workloads [2] (but to be clear, it is not used by Firefox's Wasm JIT to run Wasm in websites)
Re your question about possible negative displacements --- given that Wasm's memory op supports an linear memory offset specified as the sum of 32-bit variable `offset` and 32-bit `constant`, the straightforward encoding `gs: constant(%reg_offset)` is possible only when the constant is <= INT32_MAX (which is true most of the time).
If we run into a larger constant than that, I expect that we just fall back to using two instructions
```
reg_tmp = offset + constant
val = gs:reg_tmp
```
The nice bit is that the wasm2c implementation doesn't really need to think about any of this, and can just defer to clang due to the `__seg_gs` syntax [3] i.e., named address space support :)
[1] https://hacks.mozilla.org/2021/12/webassembly-and-back-again-fine-grained-sandboxing-in-firefox-95/
[2] https://shravanrn.com/pubs/seguecg.pdf
[3] https://github.com/WebAssembly/wabt/blob/main/src/template/wasm2c.declarations.c#L55C48-L55C56
Now up on the newsletter, part 6 in my series on memory management, this time covering basic garbage collection techniques.
Now up on the newsletter, the fifth post in my series on memory management: Fighting With Rust
Now up, part 4 of my series on memory management: Rust Ownership and Borrowing
Joseph Lorenzo Hall, PhD
Shravan Ravi Narayan
