Low Power Branch Target Buffer

• Main Authors: Yau-Chong Hu, 胡耀中
• Other Authors: Chung-Ping Chung
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/73207446248390639056

碩士 === 國立交通大學 === 資訊工程系所 === 93 === This research reduces power consumption of branch target buffer (BTB) --- a commonly used dynamic branch prediction component. Conventional BTB is looked up while instruction fetcher is fetching an instruction. The result returned from BTB tells instruction fetcher the address of the next instruction. Since branch instructions occupy a small portion of total executed instructions, most BTB look-up operations are only waste power. We can reduce its power consumption by reducing useless BTB look-up counts. By recording the positions of branch instructions during run time, we can determine what time should instruction fetcher perform BTB look-up operation. This design is evaluated by two metrics: energy consumption and performance loss. The experimental result shows this design effectively saves energy consumption with only a little performance loss.