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Summary: DAP Spr.`98 ©UCB 1
Lecture 4:
Tomasulo Algorithm and Dynamic
Branch Prediction
Professor David A. Patterson
Computer Science 252
Spring 1998
DAP Spr.`98 ©UCB 2
Review: Summary
· Instruction Level Parallelism (ILP) in SW or HW
· Loop level parallelism is easiest to see
· SW parallelism dependencies defined for program,
hazards if HW cannot resolve
· SW dependencies/compiler sophistication determine if
compiler can unroll loops
Memory dependencies hardest to determine
· HW exploiting ILP
Works when can't know dependence at run time
Code for one machine runs well on another
· Key idea of Scoreboard: Allow instructions behind stall
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