Sergei Shulepov

TBH, I don't fully understand the idea. > This problem is not just about page size. For ewasm contracts, set-up time (instantiation including parsing, memory allocation, importing, etc) often dominates...

Isn’t this operations are partial, i.e not defined on the full input domain space? If so, these operators should trap instead of return non deterministic results?

yeah i mean that these operators are already act deterministically on all of their inputs. So I’m not sure what you mean

Sorry for terse answers, I was commuting. 1. Let's take [`idiv_un(i1, i2)`](https://webassembly.github.io/spec/core/exec/numerics.html#op-idiv-u) for example. 2. It states, that if i2 is 0, then the result is undefined. 3. In context...

Yeah, sure, for example take a look at [this one](https://github.com/WebAssembly/testsuite/blob/8958a44bf8b3dbf9e48dd1c44ee566e8bf682abe/i32.wast#L82)

I think that's not a bug but just unfortunate wording issue: [partial **functions**](https://en.wikipedia.org/wiki/Partial_function) are "undefined" on some of their inputs, and the instructions are always traps when functions they invoking...

regarding this: ``` In the WebAssembly Javascript API however the start function is executed right during instantiation, which leaves no time for the client to acquire the memory area. ```...

Hey! I think docs in stack-height instrumentation do pretty good job explaining the solution. https://github.com/paritytech/wasm-utils/blob/0380e4fa8e6a1cb5ed6bf609900015d3ae7c1ebd/src/stack_height/mod.rs#L1-L49 But If you (or anyone) run into questions pleask ask!

Thank you for taking a look! Yes, @alexcrichton, this PR is very raw right, way much less that I prefer right now. Sorry about that. I was eager to create...

Oh, yes, definitely. On top of that, the query should be a bit more smarter. It should only return true if `pc` is in a wasm module that defines r15...