Thermometer
S.P. Song, Tanvir Ahmed Khan, Sara Mahdizadeh Shahri, Akshitha Sriraman, Niranjan Kumar Soundararajan, Sreenivas Subramoney, Daniel A. Jiménez, Heiner Litz, Baris Kasikci · 2022
Modern processors employ a decoupled frontend with Fetch Directed Instruction Prefetching (FDIP) to avoid frontend stalls in data center applications. However, the large branch footprint of data center applications precipitates frequent Branch Target Buffer (BTB) misses that prohibit FDIP from eliminating more than 40% of all frontend stalls. We find that the state-of-the-art BTB optimization techniques (e.g., BTB prefetching and replacement mechanisms) cannot eliminate these misses due to their inadequate understanding of branch reuse behavior in data center applications.