4
Liebranca
156d

I'm in a big fat fucking stinking rut, as in progress on this project has absolutely stagnanted.

Gonna rubber face your duck now **UNZIPS** excepts I don't have zippers, as joggers are the one true way; fake Adidas til I fucking drop.

Brain damage aside, I understand both how I've layed out the data and what I'm supposed to do with it. We have a virtual machine, an array of instructions and arguments for a given process within it, and we need to walk this array and map values to registers.

We also need to spill values inside registers to stack, IF they are required at a further point within that block. This also isn't terribly complex. We simply look forward in the array and see if the value is an argument to any instruction that *needs* this value to be loaded (ie, within a register).

So this implies multiple iterations; we need to better understand how one particular value is used throughout an F before we can make a final decision on how many registers and stack space are actually needed for the whole block.

Here's where it gets tricky. If there's a call, we need to be certain that the symbol being invoked has already been fully processed. Besides the obvious fact that recursion fucks me up, there's another matter: say a private method gets invoked by another private method. We can take advantage of this, by which I mean, sacrilege incoming so put on this toga.

Looking at the output for C compilers, it would seem this is not done in practice, I would assume because it's a pain in the ass. But when you have the guarantee that F will only be called internally, as that's what "private" means, there's two ways it can go:

0. It's well below the 13-20 cycle threshold, so you inline the fucker. No suprises there.
1. It's a more involved affaire, and invoked in more than one place, so you don't inline it. Codesize matters.

Recursion and [1] are the big deal things holding me back. Not because it's too hard, like I said this is kindergarten level abstraction. I'm just slow and fanatical, which is how I prefer to spell "constant obsessive paranoid delusions". I can see the potential optimization I can pull here, so I'm stuck trying to figure it out.

Idea would be, handling the register allocation and stack spill for an internal-internal (or deep internal; what we like to call a "guts" method) in synchronization with the *calling* processes. This is, fundamentally, violating all conventions -- but so under the hood no one will notice.

Let me give you an example. If we were to pass some value to a function, expecting to mutate it and get a different value back, in a lot of cases it'd be stupid to make an implicit copy by using two registers, one for input and another for the output. Dude, it's one cycle. Multiply it by a million, say sixty times per second, for every time you __needlessly__ make a copy of a value that we've already stated is mutable.

Clearly unacceptable. This is, in the strictest sense, everywhere in every single codebase. Premature micro optimization is the root of all goodness, God is great and praiseworthy. So how do we go about it?

Answer is I know and I don't know. By which I mean to say, this very thing I've done by hand. Assembly is fun. Now the issue is teaching a calculator how to do it. Not so fun.

There is a dependency chain between processes, as I believe I've kind of alluded to. I'm trying to make decisions on the side of the caller depending on the details of the callee, which is why recursion is rawdogging my soul. This is the same situation, it's inverting the direction of one or more links in the dependency chain, which makes no fucking sense.

And yet it does.
Brain, explain yourself.

How do *you* handle this without crashing?
Brain?

<<ME STEWPED; BEEP-BOOP>>

Alright then, that was a useless attempt at fuckery. Let's have a nap then, maybe it'll come to me in the morning. That's what I've been saying to myself for almost a month now.

Perhaps it is a hardcoded fuk.

Comments
  • 1
    This confirms what I have always feared: working with that low-level stuff will ultimately drive you barking mad.
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