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@eshelman
eshelman / latency.txt
Last active May 7, 2024 17:49 — forked from jboner/latency.txt
HPC-oriented Latency Numbers Every Programmer Should Know
Latency Comparison Numbers
--------------------------
L1 cache reference/hit 1.5 ns 4 cycles
Floating-point add/mult/FMA operation 1.5 ns 4 cycles
L2 cache reference/hit 5 ns 12 ~ 17 cycles
Branch mispredict 6 ns 15 ~ 20 cycles
L3 cache hit (unshared cache line) 16 ns 42 cycles
L3 cache hit (shared line in another core) 25 ns 65 cycles
Mutex lock/unlock 25 ns
L3 cache hit (modified in another core) 29 ns 75 cycles
@robrich
robrich / README.md
Last active May 7, 2024 13:24
the definitive deep dive into the .git folder

the definitive deep dive into the .git folder

Thanks for joining us for "the definitive deep dive into the .git folder". It's an incredible live-demo where we open every file in the .git folder and show what it does.

Links

Here's the links we saw:

@staltz
staltz / introrx.md
Last active May 7, 2024 09:38
The introduction to Reactive Programming you've been missing
@mbinna
mbinna / effective_modern_cmake.md
Last active May 6, 2024 17:19
Effective Modern CMake

Effective Modern CMake

Getting Started

For a brief user-level introduction to CMake, watch C++ Weekly, Episode 78, Intro to CMake by Jason Turner. LLVM’s CMake Primer provides a good high-level introduction to the CMake syntax. Go read it now.

After that, watch Mathieu Ropert’s CppCon 2017 talk Using Modern CMake Patterns to Enforce a Good Modular Design (slides). It provides a thorough explanation of what modern CMake is and why it is so much better than “old school” CMake. The modular design ideas in this talk are based on the book [Large-Scale C++ Software Design](https://www.amazon.de/Large-Scale-Soft

FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.


Effective Engineer - Notes

What's an Effective Engineer?

@nadavrot
nadavrot / Matrix.md
Last active May 5, 2024 08:37
Efficient matrix multiplication

High-Performance Matrix Multiplication

This is a short post that explains how to write a high-performance matrix multiplication program on modern processors. In this tutorial I will use a single core of the Skylake-client CPU with AVX2, but the principles in this post also apply to other processors with different instruction sets (such as AVX512).

Intro

Matrix multiplication is a mathematical operation that defines the product of

@shafik
shafik / WhatIsStrictAliasingAndWhyDoWeCare.md
Last active May 2, 2024 15:08
What is Strict Aliasing and Why do we Care?

What is the Strict Aliasing Rule and Why do we care?

(OR Type Punning, Undefined Behavior and Alignment, Oh My!)

What is strict aliasing? First we will describe what is aliasing and then we can learn what being strict about it means.

In C and C++ aliasing has to do with what expression types we are allowed to access stored values through. In both C and C++ the standard specifies which expression types are allowed to alias which types. The compiler and optimizer are allowed to assume we follow the aliasing rules strictly, hence the term strict aliasing rule. If we attempt to access a value using a type not allowed it is classified as undefined behavior(UB). Once we have undefined behavior all bets are off, the results of our program are no longer reliable.

Unfortunately with strict aliasing violations, we will often obtain the results we expect, leaving the possibility the a future version of a compiler with a new optimization will break code we th

@denji
denji / http-benchmark.md
Last active May 2, 2024 06:26
HTTP(S) Benchmark Tools / Toolkit for testing/debugging HTTP(S) and restAPI (RESTful)
@x0nu11byt3
x0nu11byt3 / elf_format_cheatsheet.md
Created February 27, 2021 05:26
ELF Format Cheatsheet

ELF Format Cheatsheet

Introduction

Executable and Linkable Format (ELF), is the default binary format on Linux-based systems.

ELF

Compilation