kj800x

preface: Posting these online since it sounds like these notes are somewhat interesting based on a few folks I've shared with. These are semi-rough notes that I basically wrote for myself in case I ever needed to revisit this fix, so keep that in mind.

I recently bought an LG ULTRAGEAR monitor secondhand off of a coworker. I really love it and it's been great so far, but I ran into some minor issues with it in Linux. It works great on both Mac and Windows, but on Linux it displays just a black panel until I use the second monitor to go in and reduce the refresh rate down to 60 Hz.

This has worked decent so far but there's some issues:

• It doesn't work while linux is booting up. The motherboards boot sequence is visible just fine, but as soon as control is handed over to Linux and I'd normally see a splash screen while I'm waiting for my login window, I see nothing.
• It doesn't work on the login screen. This would be fine if login consistently worked on my second screen, but I need to manually switch

VictorTaelin

Implementing complex numbers and FFT with just datatypes (no floats)

In this article, I'll explain why implementing numbers with just algebraic datatypes is desirable. I'll then talk about common implementations of FFT (Fast Fourier Transform) and why they hide inherent inefficiencies. I'll then show how to implement integers and complex numbers with just algebraic datatypes, in a way that is extremely simple and elegant. I'll conclude by deriving a pure functional implementation of complex FFT with just datatypes, no floats.

FCLC

Context

I was helping a few computer science students and enthusiasts understand “how” modern processors got to be “so fast” outside of clock speed increases.  

Here is the main ;p exert  

Acronyms:  

SIMD: Single Instruction, Multiple Data  

Marc-B-Reynolds

click for range breakdown

checking on [3f800000,40000000] [1.000000e+00,2.000000e+00]

func	e	max ULP	CR	FR	2 ULP	> 2 ULP	CR%	FR%	2 ULP%	> 2 ULP%
vrsqrte_f32	--	4947968	103	225	216	8388065	0.001228	0.002682	0.002575	99.993515
FRSR_Mon0	--	564177	3	8	6	8388592	0.000036	0.000095	0.000072	99.999797
FRSR_Deg0	--	403258	0	0	0	8388609	0.000000	0.000000	0.000000	100.000000
FRSR_Mon1	--	14751	230	464	466	8387449	0.002742	0.005531	0.005555	99.986172

lithdew

const std = @import("std");

const sparse = @This();

/// This is an implementation of a paged sparse set that stores the payload in
/// the sparse array.
//
/// A sparse set has a dense and a sparse array. The sparse array is directly
/// indexed by a 64 bit identifier. The sparse element is linked with a dense
/// element, which allows for liveliness checking. The liveliness check itself

zingaburga

ARM’s Scalable Vector Extensions: A Critical Look at SVE2 For Integer Workloads

Scalable Vector Extensions (SVE) is ARM’s latest SIMD extension to their instruction set, which was announced back in 2016. A follow-up SVE2 extension was announced in 2019, designed to incorporate all functionality from ARM’s current primary SIMD extension, NEON (aka ASIMD).

Despite being announced 5 years ago, there is currently no generally available CPU which supports any form of SVE (which excludes the [Fugaku supercomputer](https://www.fujitsu.com/global/about/innovation/

bitonic

// Copyright (c) 2021 Francesco Mazzoli <f@mazzo.li>
//
// Permission to use, copy, modify, and distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

slotrans

/*
Replace "your_schema" with whatever schema is appropriate in your environment.
It is possible to use "public"... but you shouldn't!
*/


/*
Function to stamp a "modified" timestamp. Adjust the name to suit your environment,
but that name is hard-coded so it is assumed that you only use _one_ such name.

chrispsn

WAR ON RAZE

This is the story of what happened when I went down a rabbit hole.

It starts with k7. If you press Ctrl-] in the k7 WASM console, this appears:

x^x*/:x:2_!100

That's a prime number filter. There are faster ones - kparc.com's x,1_&&/80#'!:'x is beautiful - but this one is really short.

pervognsen

A traditional table-based DFA implementation looks like this:

uint8_t table[NUM_STATES][256]

uint8_t run(const uint8_t *start, const uint8_t *end, uint8_t state) {
    for (const uint8_t *s = start; s != end; s++)
        state = table[state][*s];
    return state;
}