Tesla has started rolling out Full Self-Driving (Supervised) v14.3 to HW4 vehicles, and the headline change is under the hood: Tesla rewrote the AI compiler and runtime from scratch on MLIR, which the automaker says delivers a 20% faster reaction time. The update, shipping as software version 2026.2.9.6, also brings a new parking spot pin on the map, better behavior around emergency vehicles and school buses, and Tesla’s first public acknowledgement that it’s leaning on MLIR — the compiler infrastructure built by Chris Lattner, who briefly led Tesla Autopilot back in 2017. What’s new in FSD v14.3 Here are Tesla’s official release notes for Full Self-Driving (Supervised) v14.3, shipping on build 2026.2.9.6 for HW4 Model S, 3, X, Y, and Cybertruck: Upgraded the Reinforcement Learning (RL) stage of training the FSD neural network, resulting in improvements in a wide variety of driving scenarios. Upgraded the neural network vision encoder, improving understanding in rare and low-visibility scenarios, strengthening 3D geometry understanding, and expanding traffic sign understanding. Rewrote the AI compiler and runtime from the ground up …