Advanced Computer Architecture, Imperial College 2001
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Predication
- issues
•Predication is useful when
–conditional body is short
–branch prediction accuracy is poor
•Predication requires space in the instruction encoding
•Particularly valuable with wide multi-issue (why?)
•Can affect the prediction accuracy of other branches
•Not to be confused with speculative execution:
–with predication, depends on preceding instructions
–with speculation, depends on later instructions