发明授权
- 专利标题: Using a modified value GPR to enhance lookahead prefetch
- 专利标题(中): 使用修改值GPR来增强前瞻预取
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申请号: US12061290申请日: 2008-04-02
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公开(公告)号: US07620799B2公开(公告)日: 2009-11-17
- 发明人: Richard James Eickemeyer , Hung Qui Le , Dung Quoc Nguyen , Benjamin Walter Stolt , Brian William Thompto
- 申请人: Richard James Eickemeyer , Hung Qui Le , Dung Quoc Nguyen , Benjamin Walter Stolt , Brian William Thompto
- 申请人地址: US NY Armonk
- 专利权人: International Business Machines Corporation
- 当前专利权人: International Business Machines Corporation
- 当前专利权人地址: US NY Armonk
- 代理商 Stephen J. Walder, Jr.; Diana R. Gerhardt
- 主分类号: G06F9/30
- IPC分类号: G06F9/30 ; G06F9/40 ; G06F15/00
摘要:
Mechanisms to identify and speculatively execute future instructions during a stall condition are provided. In speculative mode, instruction operands may be invalid due to a number of reasons. Dependency and dirty bits are tracked and used to determine which speculative instructions are valid for execution. A modified value register storage and bit vector are used to improve the availability of speculative results that would otherwise be discarded once they leave the execution pipeline because they cannot be written to the architected registers. The modified general purpose registers are used to store speculative results when the corresponding instruction reaches writeback and the modified bit vector tracks the results that have been stored there. Younger speculative instructions that do not bypass directly from older instructions use this modified data when the corresponding bit in the modified bit vector indicates the data has been modified. Otherwise, data from the architected registers is used.
公开/授权文献
- US20080250230A1 Using a Modified Value GPR to Enhance Lookahead Prefetch 公开/授权日:2008-10-09