| 摘要 |
PROBLEM TO BE SOLVED: To provide a branch predicting system using a PHT capable of improving the precision of branch prediction by preventing any entry interference while using a memory capacity which is as small as possible. SOLUTION: A branch predicting device is provided with a history register for holding the history of the past branch instructions, an index generating circuit for generating a first index from the history held by the history register and an instruction address, a history table for storing a tag being a part of the instruction address and a first value indicating the easiness of branching with respect to the first index, a branch destination buffer for storing the branch destination address of the instruction indicated by the instruction address and a second value indicating the easiness of branching by using at least a part of the instruction address as a second index, and a selecting unit for executing branch prediction by selecting either the first value or the second value.
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