Assembly IO instruction refactoring

[bobbinth]

IO operations are the only ones currently left still use "dot-format" (underscore format). As discussed in #329, it might be good to move them to the underscore format as well. Additionally, I think it might be a good opportunity for a bigger refactoring. Specifically, I'm thinking we could do the following:

• push operation stays as is now.
• push.env.sdepth -> sdepth
• push.env.locaddr -> locaddr
• push.mem -> mem_load
• pushw.mem delete
• loadw.mem -> mem_loadw
• push.mem -> mem_store
• popw.mem delete
• storew.mem -> mem_storew
• push.local -> loc_load
• pushw.local delete
• loadw.local -> loc_loadw
• pop.local -> loc_store
• popw.local -> delete
• storew.local -> loc_storew

The motivation behind removing some operations is that these are expensive operations and frequently their use can be eliminated by more efficient use of load and store operations.

[itzmeanjan]

I think this will make instructions look more familiar --- cognitive parsing becomes easier.

[grjte]

I'm in favor of getting rid of pushw and popw. They both have a big performance penalty that's a bit opaque right now, so it's probably better if people have to explicitly pad the stack & see the cycle cost whenever they need this functionality.

If we're getting rid of pushw/popw, I'd change push/pop for memory & locals to to load/store for the same reason. Otherwise I think the same performance issue is likely to manifest itself in those instructions.

As mentioned in the other issue, I'm also in favor of switching to underscores, and I think the change to the env instructions makes sense here as well.

[bobbinth]

I'd change push/pop for memory & locals to to load/store

Agreed! I've updated the original post.

[bobbinth]

Closed by #393