# R3-DLA (Reduce, Reuse, Recycle): A More Efficient Approach to Decoupled Look-Ahead Architectures

## TL;DR

This paper introduces R3-DLA, an optimized decoupled look-ahead architecture that significantly improves single-thread performance by making look-ahead agents more efficient, achieving an average speedup of 1.4 over existing microarchitectures.

## Contribution

It proposes a set of optimizations for decoupled look-ahead architectures, enhancing efficiency and utility, leading to notable performance improvements.

## Key findings

- Achieves an average speedup of 1.4 over state-of-the-art microarchitecture.
- Enhances single-thread performance across diverse benchmarks.
- Demonstrates broad applicability of optimized DLA in general-purpose computing.

## Abstract

Modern societies have developed insatiable demands for more computation capabilities. Exploiting implicit parallelism to provide automatic performance improvement remains a central goal in engineering future general-purpose computing systems. One approach is to use a separate thread context to perform continuous look-ahead to improve the data and instruction supply to the main pipeline. Such a decoupled look-ahead (DLA) architecture can be quite effective in accelerating a broad range of applications in a relatively straightforward implementation. It also has broad design flexibility as the look-ahead agent need not be concerned with correctness constraints. In this paper, we explore a number of optimizations that make the look-ahead agent more efficient and yet extract more utility from it. With these optimizations, a DLA architecture can achieve an average speedup of 1.4 over a state-of-the-art microarchitecture for a broad set of benchmark suites, making it a powerful tool to enhance single-thread performance.