Update to nightly-2023-08-29

[LegNeato]

EDIT(@eddyb): initial PR by @LegNeato but I added to it to avoid creating another PR (#1091 (commits)).

[LegNeato]

This builds successfully for me locally but panics when using GPU stuff (CPU example works fine). I have never touched the compiler or this project so I don't really know what I am doing 😆

[LegNeato]

I'm fairly sure the problems are in the type pointer stuff, changed in rust-lang/rust@04303cf

[LegNeato]

I managed to get it further along by adding let ptr = self.pointercast(ptr, self.type_ptr_to(ty));
to various places. It looks like the above change removes those before calling things like load and store.

[LegNeato]

I also needed to add a new intrinsic compare_bytes due to rust-lang/rust@502af03.

[LegNeato]

When I don't add the pointer casts, it compiles but I get:

TODO: intcast not implemented yet: val=SpirvValue { kind: Def(14981), ty: 54 } val.ty=Adt { def_id: Some(DefId(0:34076 ~ core[e34c]::option::Option)), align: Align(4 bytes), size: Some(Size(8 bytes)), field_types: [4, 4], field_offsets: [Size(0 bytes), Size(4 bytes)], field_names: None } dest_ty=Integer(32, true) is_signed=false

When I do, it gets all the way to compiling the shader but bails on converting a *void to a *i32 IIRC.

[eddyb]

Hi, sorry to barge in with those commits, but I went ahead and finished this PR - it turned out to be pretty nasty and I'm not that happy with my approach (it's now conservative when creating pointers, but aggressive when accessing them).

So I really hope you didn't waste too much time trying to make it all work (also, feel free to poke me on Discord etc. any time, esp. if you want any feedback, I tend to mainly get GH notifs for a direct ping, i.e. @eddyb).

[LegNeato]

Thanks completing this! I like to dive into the deep end in codebases to try to learn them, so the time I spent poking at this was time well spent. Doubly so now that I've seen your changes and can compare them to the mental model I built up.