The Raspberry Pico Microcontroller: Hardware and GPIO Functions

The Raspberry Pi Pico, or shorthand Pico, is a new microcontroller from the Raspberry Pi foundation....

https://medium.com/geekculture/the-raspberry-pico-microcontroller-hardware-and-gpio-functions

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#raspberry #hardware #cpp

Free Geoip Api

Free ip geolocation api using c++ and php

https://github.com/Markus-Go/ip-countryside

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#cpp #php #geoip

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#meme #extra #cpp

C++ for Python

Cppyy is a python library to make C++ bindings for your application.

https://github.com/wlav/cppyy

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#cpp #library #python

Rust vs C++ – which is better and why

Both Rust and C++ are system programming languages, which means they can be used to write low-level code like kernels...

https://federicoterzi.com/blog/rust-vs-cpp-which-is-better-and-why/

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#rust #cpp #webasm

Google SAPI

Generate sandboxes for C/C++ libraries automatically.

https://github.com/google/sandboxed-api

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#google #tools #c #cpp

The Evolutions of Lambdas in C++14, C++17 and C++20

https://www.fluentcpp.com/2021/12/13/the-evolutions-of-lambdas-in-c14-c17-and-c20/

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#cpp #lambda #fp #learn

I Coded a Video Editor (and it kind of sucks)

Coding a video editor in a week 8 months with C++/OpenGL/Imgui.

https://youtu.be/iydG-e1dQGA

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#cpp #graphics #misc

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#meme #cpp #clang

Can you use a C++ class in C?

https://d4ckard.github.io/2023/08/11/can-you-use-a-class-in-c/

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#c #cpp #learn

Common programming mistakes (C++)

https://develop.kde.org/docs/getting-started/common-programming-mistakes/

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#learn #cpp #misc

Why German Strings are Everywhere

- Developed by Umbra (CedarDB's predecessor)
- Adopted by DuckDB, Apache Arrow, Polars, and Facebook Velox

German Strings are a custom string type highly optimized for data processing. They offer significant improvements over traditional C and C++ string implementations.

Key Features:
- 128-bit struct representation (vs. 192 bits in C++)
- Short string optimization for strings ≤12 characters
- Long string format with 4-char prefix for quick comparisons
- Immutable design for better performance and concurrency
- Storage classes: persistent, transient, temporary

Advantages:
- Space-efficient, fitting in two CPU registers
- Reduced allocations and data movement
- Easier parallelization due to immutability
- Flexible lifetime management with storage classes
- Optimized for common database operations (comparisons, sorting)

Trade-offs:
- Requires careful consideration of string usage and lifetime
- Updates are more expensive (but rare in database systems)
- Maximum string length limited to 4 GiB

https://cedardb.com/blog/german_strings/

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#cpp #data #misc

Counting Bytes Faster Than You'd Think Possible

- The author was able to significantly optimize a byte-counting program, achieving a ~550x speedup over a naive implementation.
- The key optimization was using an interleaved memory access pattern, reading from different 4KB pages in a round-robin fashion, instead of sequential access.
- This interleaved access pattern takes advantage of the "Streamer" hardware prefetcher in modern CPUs, which can maintain separate forward and backward access streams for each 4KB page.
- Interleaving 8 different 4KB pages was found to be the optimal approach, providing up to a 30% performance boost over sequential access.
- The author also unrolled the inner loop to process 2 cache lines (64 bytes) at a time, and added a prefetch instruction to fetch the next set of data.
- The final solution uses AVX2 SIMD instructions to perform the byte counting in a highly efficient manner.
- The author was able to achieve a ranking of #13 on the HighLoad leaderboard with this optimized solution.
- The interleaved memory access pattern seems to be an under-discussed optimization technique, with the author not recalling seeing it used in other code.
- The author encourages readers to share any other memory-based optimizations they are aware of, as the author is interested in learning about them.
- The document provides the full source code for the optimized byte-counting program, allowing readers to study and potentially apply the techniques in their own work.

https://blog.mattstuchlik.com/2024/07/21/fastest-memory-read.html

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#asm #cpp #optimization