摘要:
The present invention relates to an information processing apparatus predicting a branch destination of a branch instruction using a branch history register to realize effective replacement by enabling an unnecessary entry to be selected as an entry, which is an object of replacement, without using new resources in a full-associative memory device. The invention includes a selector for selecting one entry from all entries of a past branch history memory section if all entries of the past branch history memory section are in use when a branch history about a new branch instruction is registered into the past branch history memory section and a replacing section for registering the branch history about the new branch instruction into one entry selected by said selector, wherein the selector has a first selecting function of selecting one entry based on the branch history held by the past branch history memory section.
摘要:
A branch history stores execution history information of branch instructions, and predicts presence of a branch instruction and a corresponding branch destination. A first return address stack stores, when an execution of a call instruction of a subroutine is completed, address information of a return destination of a corresponding return instruction. A second return address stack stores, when presence of a call instruction of a subroutine is predicted, address information of a return destination of a corresponding return instruction. An output selecting unit selects, when presence of a return instruction is predicted, if address information is stored in the second return address stack, the address information as a result of the branch prediction with a highest priority, and outputs the address information selected.
摘要:
The present invention is a branch prediction device comprising a branch history storage device for storing branch history information in order to predict branch behavior, an error detection mechanism for detecting the reading error of the branch history information, and an erasure mechanism for erasing the storage region of the branch history information in which the reading error is detected.
摘要:
A memory access method is employed in a multiprocessor system which includes a plurality of system modules coupled via a crossbar module, where each of the system modules includes a buffer which holds data and a plurality of processors having a cache memory which temporarily holds data. The memory access method includes a step, responsive to a read request from a processor within an arbitrary system module, holding data preread from a system module other than the arbitrary system module in a buffer within the crossbar module.
摘要:
A branch history stores execution history information of branch instructions, and predicts presence of a branch instruction and a corresponding branch destination. A first return address stack stores, when an execution of a call instruction of a subroutine is completed, address information of a return destination of a corresponding return instruction. A second return address stack stores, when presence of a call instruction of a subroutine is predicted, address information of a return destination of a corresponding return instruction. An output selecting unit selects, when presence of a return instruction is predicted, if address information is stored in the second return address stack, the address information as a result of the branch prediction with a highest priority, and outputs the address information selected.
摘要:
A branch history stores execution history information of branch instructions, and predicts presence of a branch instruction and a corresponding branch destination. A first return address stack stores, when an execution of a call instruction of a subroutine is completed, address information of a return destination of a corresponding return instruction. A second return address stack stores, when presence of a call instruction of a subroutine is predicted, address information of a return destination of a corresponding return instruction. An output selecting unit selects, when presence of a return instruction is predicted, if address information is stored in the second return address stack, the address information as a result of the branch prediction with a highest priority, and outputs the address information selected.
摘要:
A branch prediction apparatus includes a branch information receiving unit that receives simultaneously, branch information for each of a plurality of branch instructions that are completed simultaneously, and a parallel branch predicting unit that performs branch prediction in parallel for the branch instructions completed simultaneously, based on the branch information received and a branch history of the respective branch instructions, to obtain branch prediction results.
摘要:
The present invention relates to an information processing apparatus predicting a branch destination of a branch instruction using a branch history register to realize effective replacement by enabling an unnecessary entry to be selected as an entry, which is an object of replacement, without using new resources in a full-associative memory device. The invention includes a selector for selecting one entry from all entries of a past branch history memory section if all entries of the past branch history memory section are in use when a branch history about a new branch instruction is registered into the past branch history memory section and a replacing section for registering the branch history about the new branch instruction into one entry selected by said selector, wherein the selector has a first selecting function of selecting one entry based on the branch history held by the past branch history memory section.