A power-aware branch predictor by accessing the btb selectively 一個有選擇性訪問btb的功耗敏感型分枝預測器
This paper proposes a power-aware branch predictor, which is based on the gshare predictor, by accessing the btb branch target buffer selectively 本文提出的是一個功耗敏感型的分枝預測器,它是基于gshare的一個有選擇性訪問btb的預測器。
Microarchitects should consider power consumption, together with accuracy, when designing a branch predictor, especially in embedded processors 在設(shè)計分枝預測器時,尤其是在設(shè)計嵌入式處理器中的分枝預測器時,微電子設(shè)計師應該考慮功耗及精度。
The proposed branch predictor reduces the power consumption with little hardware overhead, not incurring additional delay and never harming prediction accuracy 本文提出的分枝預測器能夠降低功耗,硬件開銷很小,不會招致額外的延遲而且決不會影響預測精度。
In the proposed branch predictor, if the previous instruction was not a branch and the prediction from the pht is untaken, the btb is not accessed to reduce power consumption 在本文提出的分枝預測器中,如果前一條指令不是一個分枝且pht的預測尚未執(zhí)行,那么btb就不被訪問以降低功耗。
Dongrui fan, hongbo yang, guangrong gao et al ., “ evaluation and choice of various branch predictors for low-power embedded processor ”, journal of computer science & technology, vol . 18 no . 6, nov . 2003 范東睿,“不同層面上處理器功耗評估工具的對比研究”,第八屆計算機科學與技術(shù)學術(shù)研討會,大連,2004年7月。
Tpbtp mechanism evaluates branch target from a direct branch in advance, so to make up the insufficiency of branch predictor and branch target buffer, and constructs instruction traces before program execution tpbtp機制從直接分支指令中提取目標地址,彌補分支預測和分支目標緩存的不足,加速指令讀取,實現(xiàn)trace預構(gòu)。
Then, the work researches multithread processor architecture based on the armp . this dissertation focused on the branch predictor of high performance processor and fetch unit of selective execution of multithread architecture 接著,本文以armp為基礎(chǔ)深入了解國內(nèi)外目前最先進的多線程處理器系統(tǒng)結(jié)構(gòu)研究工作,明確了該領(lǐng)域研究的發(fā)展方向和研究難點。
To enable the selective access to the btb, the pht pattern history table in the proposed branch predictor is accessed one cycle earlier than the traditional pht if the program is executed sequentially without branch instructions 如果程序是在無分枝指令情況下順序執(zhí)行,為了使能對btb有選擇性的訪問,本文提出的分枝預測器中的pht要比傳統(tǒng)的pht提早一個周期訪問。
Several other implementation issues, including instruction window size, issue width and branch predictor are also addressed and simulated . simulation results indicate that data value predictors act differently under different configurations 值預測是一種預測機制,它基于指令已產(chǎn)生結(jié)果的特征預測指令未來將要產(chǎn)生結(jié)果,從而使后續(xù)相關(guān)指令得以利用預測值前瞻執(zhí)行。