MANAGING INSTRUCTION ORDER IN A PROCESSOR PIPELINE

摘要

Executing instructions in a processor includes classifying, in at least one stage of a pipeline of the processor, operations to be performed by instructions. The classifying includes: classifying a first set of operations as operations for which out-of-order execution is allowed, and classifying a second set of operations as operations for which out-of-order execution with respect to one or more specified operations is not allowed, the second set of operations including at least store operations. Results of instructions executed out-of-order are selected to commit the selected results in-order. The selecting includes, for a first result of a first instruction and a second result of a second instruction executed before and out-of-order relative to the first instruction: determining which stage of the pipeline stores the second result, and committing the first result directly from the determined stage over a forwarding path, before committing the second result.

主权项

1. A method for executing instructions in a processor, the method comprising:
classifying, in at least one stage of a pipeline of the processor, operations to be performed by instructions, the classifying including:
classifying a first set of operations as operations for which out-of-order execution is allowed, andclassifying a second set of operations as operations for which out-of-order execution with respect to one or more specified operations is not allowed, the second set of operations including at least store operations; and selecting results of instructions executed out-of-order to commit the selected results in-order, the selecting including, for a first result of a first instruction and a second result of a second instruction executed before and out-of-order relative to the first instruction:
determining which stage of the pipeline stores the second result, andcommitting the first result directly from the determined stage over a forwarding path, before committing the second result.