Looking ahead bytecode stream to generate and update prediction information in branch target buffer for branching from the end of preceding bytecode handler to the beginning of current bytecode handler

摘要

A bytecode interpreter is provided. The interpreter assists in branch prediction by a host processor reducing branch misprediction and achieving high performance. The bytecode branch processor includes an interpreter configured to process a program in a bytecode format in a virtual machine, a branch information generator configured to obtain, while a predefined number of bytecodes are read prior to a current bytecode being processed by the interpreter, a branch address and a target address of a predicted path of a branch corresponding to a preceding bytecode, the branch address being of a branch code included in a preceding handler that processes the preceding bytecode, and the target address being of a current handler that processes the current bytecode to which the preceding handler branches, and a branch target buffer updater configured to update a branch target buffer in the bytecode branch processor with the obtained branch address and target address.

主权项

1. A bytecode branch processor, the bytecode branch processor comprising:
an interpreter configured to process a program in a bytecode format in a virtual machine; a branch information generator configured to obtain, while a predefined number of bytecodes are read prior to a current bytecode being processed by the interpreter, a branch address and a target address of a predicted path of a branch corresponding to a preceding bytecode preceding the current bytecode by using a table that comprises a preceding opcode, a length of the preceding bytecode, and the branch address, which are mapped according to the order of bytecode processing, the branch address being of a branch code included in a preceding handler that processes the preceding bytecode, and the target address being of a current handler that processes the current bytecode to which the preceding handler branches; and a branch target buffer (BTB) updater configured to update a branch target buffer (BTB) in the bytecode branch processor with the obtained branch address and target address, wherein the interpreter is further configured to process a branch prediction and to remove a branch misprediction by checking whether the obtained branch address and target address in the BTB is validated in the branch prediction of the current bytecode.