Top all-time · #7157
Follow me down the optimization rabbit hole
Personal blog · bitbanksoftware.blogspot.comprogramminghardware
Follow me down the optimization rabbit hole is a personal blog at bitbanksoftware.blogspot.com about programming and hardware. Since 2018, 11 different Hacker News readers have linked it 26 times, most often “ESP32-S3 has a few SIMD instructions”. It is still writing: the last post was on 2026-10-11, and you can follow it by feed.
Too few sampled comments (6) to say how often HN recommends it.?
Why HN links it
HN readers link Larry Bank's blog for posts on SIMD and optimization on the ESP32-S3 microcontroller, including its Xtensa instructions and compiler overflow behaviour. Comments point to these posts as references.
Summarised by Claude from a sample of 6 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
I optimize software for a living. This blog is to share some personal projects which others may find interesting.
Most-linked posts?
- ESP32-S3 has a few SIMD instructions4 people · 4 mentions · first linked 2024-05-05
- ESP32-P4 SIMD Explained2 people · 2 mentions · first linked 2026-04-11
What Hacker News says?
Also see this short post about SIMD on ESP32-S3, discussed previously. https://bitbanksoftware.blogspot.com/2024/01/surprise-esp32-...
Comment linking /2024/01/surprise-esp32-s3-has-few-simd.html
on “SIMD-accelerated computer vision on a $2 microcontroller”Submitted ESP32-S3 has a few SIMD instructions as a story · 189 points
HN discussionI think the reason that signed integer overflow is undefined is that it wasn't uncommon at the time to have architectures that didn't represent signed integers with 2's complement. Even today you may find issues with signed integers. The ESP32 vector extensions seem to saturate signed integer overflow [1]. [1]: https://bitbanksoftware.blogspot.com/2024/01/surprise-esp32-...
Comment linking /2024/01/surprise-esp32-s3-has-few-simd.html
on “Clang vs. Clang”Submitted My adventures in writing an OTA bootloader for the ATmega128RFA1 as a story · 7 points
HN discussionInteresting. Since this was implemented on the S3, which uses the ISA XTensa LX instead of the RISC-V of most newer ESP32 series chips, I looked into how Espressif is handling SIMD on the latter ISA. Apparently it is only present in limited fashion as a processor extension on the P4 and S31 [0]. The S31 datasheet claims SIMD [1] and the P4 datasheet [2] files them as "Processor Instruction Extensions." 0. https://bi…
Comment linking /2026/04/esp32-p4-simd-explained.html
on “SIMD-accelerated computer vision on a $2 microcontroller”Submitted Building the Pocket CO2 Project as a story · 5 points
HN discussionThere's also a follow-up blog post "ESP32-S3 SIMD Minimal Example" [0]. 0: https://bitbanksoftware.blogspot.com/2024/01/esp32-s3-simd-m...
Comment linking /2024/01/esp32-s3-simd-minimal-example.html
on “ESP32-S3 has a few SIMD instructions”Submitted Fast GPIO on Linux as a story · 3 points
HN discussionESP32-S3 already had SIMD, but Xtensa wasn't quite friendly about it. https://bitbanksoftware.blogspot.com/2024/01/surprise-esp32-...
Comment linking /2024/01/surprise-esp32-s3-has-few-simd.html
on “ESP32-S31”Submitted A 'Low Memory' GIF Decoder as a story · 3 points
HN discussionFor a moment I was confused why the text sounded so familiar, but then realized the author is Larry Bank and I read the post on his blog https://bitbanksoftware.blogspot.com/2021/05/the-case-of-mis... before.
Comment linking /2021/05/the-case-of-missing-simd-code.html?m=1
on “The Case of the Missing SIMD Code”Submitted Optimizing access to serial (SPI/I2C) displays as a story · 3 points
HN discussionSubmitted Optimizing your nRF24 range with a simple test rig as a story · 3 points
HN discussionSubmitted How low can you go? (Optimizing for power) as a story · 3 points
HN discussionSubmitted A few words about using SIMD instructions in your code as a story · 3 points
HN discussionSubmitted How much power does gzip save on IoT web access? as a story · 2 points
HN discussionSubmitted The Last Mile – The Problem with FOSS as a story · 2 points
HN discussionSubmitted Mind the cache (optimizing write speed on Intel CPUs) as a story · 2 points
HN discussionSubmitted ESP32-P4 SIMD Explained as a story · 1 points
HN discussionSubmitted My BLE Adventures as a story · 1 points
HN discussionSubmitted Controlling lots of I2C OLED displays with a few GPIO pins as a story · 1 points
HN discussionSubmitted Optimizing hobbyist IoT parts for power usage as a story · 1 points
HN discussionSubmitted With software, there's always a better way to do it as a story · 1 points
HN discussionSubmitted Pushing the I2C SSD1306 OLED to the limit with bit banging as a story · 1 points
HN discussionSubmitted Practical Animation on I2C SSD1306 OLED Displays as a story · 1 points
HN discussionSubmitted Optimizing JPEG Entropy Decoding as a story · 1 points
HN discussion
