ESP-S: Squeezing Performance Out of LX SIMD in

The year is and the ESP-S, a popular microcontroller in the ESP family, is making waves. Why all the hype? Well, this little chip packs a punch with its upgraded Cadence Xtensa LX processor core. But here’s the real kicker: LX’s SIMD instructions. SIMD, or Single Instruction Multiple Data, is like having a team of tiny chefs in your processor kitchen, all chopping veggies (or, in our case, processing data) simultaneously. This means faster processing, smoother performance, and happier developers.

Now, imagine harnessing this power to turbocharge video processing on a microcontroller! That’s precisely what developer extraordinaire, Shranav Palakurthi, set out to do. His mission? To make the ESP-S an even bigger beast in image processing.

Hunting Corners with SIMD: A Speedrun

Shranav wasn’t messing around. He dove headfirst into a classic computer vision problem: corner detection. Think of it like this – your phone uses corner detection to recognize faces, track objects, and even unlock with a quick scan. Shranav, being the absolute chad he is, chose the FAST method (Features from Accelerated Segment Test) for his experiment. Now, FAST is already pretty darn fast, but with LX SIMD, Shranav knew he could crank things up to eleven. His secret sauce? He strategically migrated specific operations, ripe for parallelization, to optimized LX assembly code. It was like translating a recipe from English to chef’s kiss emoji–level efficiency.

The SIMD Struggle is Real

Working with LX SIMD instructions is kinda like trying to assemble IKEA furniture… in the dark… with instructions in a language you barely understand. Yeah, it’s a vibe. The biggest hurdle? Documentation. Imagine needing to bake a cake but only having half the recipe and a cryptic note from your grandma saying, “You’ll figure it out.” That’s the LX SIMD experience in a nutshell. To make matters worse, accessing the good stuff (read: detailed documentation) requires signing an NDA with Cadence, the creators of LX. Talk about hoops to jump through!

Shranav, being the absolute trooper he is, persevered. He found himself wrangling with limitations like the lack of direct support for misaligned reads – imagine trying to read a recipe book but only being able to see every other letter! On top of that, the absence of an instruction for comparing unsigned -bit numbers was another head-scratcher. It’s like trying to bake a cake without knowing if you have enough sugar!