Lookahead Prefetching with Signature Path

Existing data prefetchers speculate on spatial and temporal locality by tracking past memory accesses. Relying on the past memory accesses restricts the scope of prefetching and potentially further performance improvement. In this paper, we propose a lookahead prefetching algorithm called Signature Path Prefetching (SPP) that accurately predicts the next memory access pattern and exploits this future access to initiate lookahead prefetching. Unlike prior lookahead algorithms, SPP is purely based on the memory access stream and does not require additional support from branch history, PC, or metadata to lookahead future memory access. Within a 32KB storage limit, we evaluate SPP under different memory constrained scenarios and find SPP outperforms the previous competition winner AMPM prefetcher by 4% performance improvement.