Microprocessor with improved data stream prefetching
US7177985B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | May 30, 2003 |
| Grant date | Feb 13, 2007 |
| Priority date | — |
| Expiry date | Jun 23, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/6028
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A microprocessor with multiple stream prefetch engines each executing a stream prefetch instruction to prefetch a complex data stream specified by the instruction in a manner synchronized with program execution of loads from the stream is provided. The stream prefetch engine stays at least a fetch-ahead distance (specified in the instruction) ahead of the program loads, which may randomly access the stream. The instruction specifies a level in the cache hierarchy to prefetch into, a locality indicator to specify the urgency and ephemerality of the stream, a stream prefetch priority, a TLB miss policy, a page fault miss policy, a protection violation policy, and a hysteresis value, specifying a minimum number of bytes to prefetch when the stream prefetch engine resumes prefetching. The memory subsystem includes a separate TLB for stream prefetches; or a joint TLB backing the stream prefetch TLB and load/store TLB; or a separate TLB for each prefetch engine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.