Ivan Pribec ivan-pi

macOS Internals

Understand your Mac and iPhone more deeply by tracing the evolution of Mac OS X from prelease to Swift. John Siracusa delivers the details.

Starting Points

How to use this gist

You've got two main options:

ANSI Escape Sequences

Standard escape codes are prefixed with Escape:

Ctrl-Key: ^[
Octal: \033
Unicode: \u001b
Hexadecimal: \x1B
Decimal: 27

Two schools

There are two schools how to write numerical code, which in this document we will call the IEEE school and the Fortran school.

One end of the spectrum: no changes in floating point by the compiler, the developer must express exact intent. This is the IEEE school.

On the other end of the spectrum: Developer specifies math, the compiler is

How to add an image to a gist

Create a gist if you haven't already.

Clone your gist:

# make sure to replace `<hash>` with your gist's hash
git clone https://gist.github.com/<hash>.git # with https
git clone [email protected]:<hash>.git     # or with ssh

	const std = @import("std");

	// Can also try:
	// 8 x 64
	// 16 x 64
	// Top GFLOPs/s on an Intel® Core™ i7-13620H Processor = 300.9 GFLOPs/s
	// Comments were added using Claude.
	// To run simply run zig build-exe -O ReleaseFast matmul_FP32.zig, then run the binary ./matmul_FP32
	// To test simply run zig test -O ReleaseFast matmul_FP32.zig
	// To test performance on a generated binary, run : sudo perf stat -e cache-misses,cache-references,instructions,cycles ./matmul_FP32

	// compile with g++ -o bisect.cxx poly.o -I<path/to/boost>

	#include <cmath>
	#include <iostream>

	#include <boost/math/tools/roots.hpp>

	// Functor providing termination condition
	// Determines convergence in x based on if the relative or absolute tolerance are satisfied
	template<class T>

	\#!/bin/bash

	whatscr() { echo "gccprefab - Wil's GCC easy build script"; }
	whenscr() { echo "Last updated: Jun 11, 2022 (WYP)"; }

	usage() { echo "Usage: $0 [options] configfile"; }

	helptext() {
	echo "Available options:"
	echo " -h, --help Display this help text"

	# 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

	/* Allocate aligned memory in a portable way.
	*
	* Memory allocated with aligned alloc MUST be freed using aligned_free.
	*
	* @param alignment The number of bytes to which memory must be aligned. This
	* value must be <= 255.
	* @param bytes The number of bytes to allocate.
	* @param zero If true, the returned memory will be zeroed. If false, the
	* contents of the returned memory are undefined.
	* @returns A pointer to `size` bytes of memory, aligned to an `alignment`-byte