ClarkThan

# IDA (disassembler) and Hex-Rays (decompiler) plugin for Apple AMX
#
# WIP research. (This was edited to add more info after someone posted it to
# Hacker News. Click "Revisions" to see full changes.)
#
# Copyright (c) 2020 dougallj


# Based on Python port of VMX intrinsics plugin:
# Copyright (c) 2019 w4kfu - Synacktiv

ClarkThan

" cat

   lac 017777 i            " Load accumulator (AC) with argument count
   sad d4                  " Skip next if we have more than 4 words of args
   jmp nofiles             " Otherwise, jump to nofiles
   lac 017777              " Load AC with address of args
   tad d1                  " Increment AC by 1, past argument count
   tad d4                  " Increment AC by 4, now AC points to first real arg
   dac name                " Save arg pointer from AC into 'name'

ClarkThan

Why stack grows down

Any running process has several memory regions: code, read-only data, read-write data, et cetera. Some regions, such as code and read-only data, are static and do not change over time. Other regions are dynamic: they can expand and shrink. Usually there are two such regions: dynamic read-write data region, called heap, and a region called stack. Heap holds dynamic memory allocations, and stack is mostly used for keeping function frames.

Both stack and heap can grow. An OS doesn't know in advance whether stack or heap will be used predominantly. Therefore, an OS must layout these two memory regions in a way to guarantee maximum space for both. And here is the solution:

1. Layout static memory regions at the edges of process's virtual memory
2. Put heap and stack on edges too, and let them grow towards each other: one grows up, one grows down

ClarkThan

(This is a translation of the original article in Japanese by moratorium08.)

(UPDATE (22/3/2019): Added some corrections provided by the original author.)

Writing your own OS to run on a handmade CPU is a pretty ambitious project, but I've managed to get it working pretty well so I'm going to write some notes about how I did it.

ClarkThan

type term =
  | Lam of (term -> term)
  | Pi of term * (term -> term)
  | Appl of term * term
  | Ann of term * term
  | FreeVar of int
  | Star
  | Box

let unfurl lvl f = f (FreeVar lvl)

ClarkThan

const std = @import("std");
const builtin = @import("builtin");

pub const Config = struct {
    /// Whether to synchronize usage of this allocator.
    /// For actual thread safety, the backing allocator must also be thread safe.
    thread_safe: bool = !builtin.single_threaded,

    /// Whether to warn about leaked memory on deinit.
    /// This reporting is extremely limited; for proper leak checking use GeneralPurposeAllocator.

ClarkThan

type binder = Lam | Pi

(* The syntax of our calculus. Notice that types are represented in the same way
   as terms, which is the essence of CoC. *)
type term =
  | Var of string
  | Appl of term * term
  | Binder of binder * string * term * term
  | Star
  | Box

ClarkThan

Memory Optimization (Christer Ericson, GDC 2003)
http://realtimecollisiondetection.net/pubs/GDC03_Ericson_Memory_Optimization.ppt

Cache coherency primer (Fabian Giesen)
https://fgiesen.wordpress.com/2014/07/07/cache-coherency/

Code Clinic 2015: How to Write Code the Compiler Can Actually Optimize (Mike Acton)
http://gdcvault.com/play/1021866/Code-Clinic-2015-How-to

ClarkThan

Achieving warp speed with Rust

Contents:

• Number one optimization tip: don't
• Never optimize blindly
• Don't bother optimizing one-time costs
• Improve your algorithms
• CPU architecture primer
• Keep as much as possible in cache
• Keep as much as possible in registers

ClarkThan

#![feature(test)]
extern crate test;

#[cfg(test)]
mod tests {
    use super::*;
    use std::fs::{File};
    use std::io::{BufWriter, Write, BufRead, BufReader};

    #[bench]