| # turn until you get three hexagons changed to get here | |
| H1 = ["AC", "AB", "ACD"] | |
| # turn until you get two hexagons changed to get here | |
| H2 = ["BCF", "ACF", "BF"] | |
| # turn until you get three hexagons changed to get here | |
| H3 = ["CD", "BC", "AB", "AF", "EF", "CDE"] | |
| # this is my status, look at the hexagons to determine which ones are open | |
| status = set("ABDE") # 110110 |
| I was drawn to programming, science, technology and science fiction | |
| ever since I was a little kid. I can't say it's because I wanted to | |
| make the world a better place. Not really. I was simply drawn to it | |
| because I was drawn to it. Writing programs was fun. Figuring out how | |
| nature works was fascinating. Science fiction felt like a grand | |
| adventure. | |
| Then I started a software company and poured every ounce of energy | |
| into it. It failed. That hurt, but that part is ok. I made a lot of | |
| mistakes and learned from them. This experience made me much, much |
This is a collection of the things I believe about software development. I have worked for years building backend and data processing systems, so read the below within that context.
Agree? Disagree? Feel free to let me know at @JanStette. See also my blog at www.janvsmachine.net.
Keep it simple, stupid. You ain't gonna need it.
| Mute these words in your settings here: https://twitter.com/settings/muted_keywords | |
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This document was originally written several years ago. At the time I was working as an execution core verification engineer at Arm. The following points are coloured heavily by working in and around the execution cores of various processors. Apply a pinch of salt; points contain varying degrees of opinion.
It is still my opinion that RISC-V could be much better designed; though I will also say that if I was building a 32 or 64-bit CPU today I'd likely implement the architecture to benefit from the existing tooling.
Mostly based upon the RISC-V ISA spec v2.0. Some updates have been made for v2.2
The RISC-V ISA has pursued minimalism to a fault. There is a large emphasis on minimizing instruction count, normalizing encoding, etc. This pursuit of minimalism has resulted in false orthogonalities (such as reusing the same instruction for branches, calls and returns) and a requirement for superfluous instructions which impacts code density both in terms of size and
| /** | |
| 1. Install the Stylish(https://chrome.google.com/webstore/detail/stylish/fjnbnpbmkenffdnngjfgmeleoegfcffe?hl=en) extension for Chrome. | |
| 2. Open up extension options and paste the CSS mentioned below. | |
| 3. Specify the "URLs on the domain" to be `github.com`. | |
| 4. Add a title and save. | |
| */ | |
| .dashboard-sidebar { | |
| float: right; | |
| padding-right: 10px; |
why doesn't radfft support AVX on PC?
So there's two separate issues here: using instructions added in AVX and using 256-bit wide vectors. The former turns out to be much easier than the latter for our use case.
Problem number 1 was that you positively need to put AVX code in a separate file with different compiler settings (/arch:AVX for VC++, -mavx for GCC/Clang) that make all SSE code emitted also use VEX encoding, and at the time radfft was written there was no way in CDep to set compiler flags for just one file, just for the overall build.
[There's the GCC "target" annotations on individual funcs, which in principle fix this, but I ran into nasty problems with this for several compiler versions, and VC++ has no equivalent, so we're not currently using that and just sticking with different compilation units.]
The other issue is to do with CPU power management.
Run the following in the terminal:
Install the gcc-7 packages:
sudo apt-get install -y software-properties-common
sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt update
sudo apt install g++-7 -y
Set it up so the symbolic links gcc, g++ point to the newer version: