| 摘要 |
A microprocessor capable of out-of-order instruction decoding and in-order dependency checking is disclosed. The microprocessor may include an instruction cache, two decode units, a reorder queue, and dependency checking logic. The instruction cache is configured to output cache line portions to the decode units. The decode units operate independently and in parallel. One of the decode units may be a split decoder that receives all instruction bytes from instructions that extend across cache line portion boundaries. The split decode unit may be configured to reassemble the instruction bytes into instructions. These instructions are then decoded by the split decode unit. A reorder queue may be used to store the decoded instructions according to their relative cache line positions. The decoded instructions are read out of the reorder queue in program order, thereby enabling the dependency checking logic to perform dependency checking in program order.
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