Allocating processor resources during speculative execution using a temporal ordering policy

摘要

One embodiment provides a system which uses a temporal ordering policy for allocation of limited processor resources. The system starts by executing instructions for a program during a normal-execution mode. Upon encountering a condition which causes the processor to enter a speculative-execution mode, the processor performs a checkpoint and commences execution of instructions in the speculative-execution mode. Upon encountering an instruction which requires the allocation of an instance of a limited processor resource during the execution of instructions in the speculative-execution mode, the processor checks a speculative-use indicator associated with each instance of the limited processor resource. Upon finding the speculative-use indicators asserted for all instances of the limited processor resource which are available to be allocated for the instruction, the processor aborts the instruction. On the other hand, upon finding the speculative-use indicator is deasserted for an instance of the limited processor resource which is available to be allocated for the instruction, the processor asserts the speculative-use indicator associated with the instance and executes the instruction.