Memory Consistency Verification of Chip Multi-Processor

Memory consistency verification is an important part of functional validation of CMP (chip multi- processor). Since checking an execution of a parallel program against a memory consistency model is known to be an NP-hard problem, in practice, incomplete verification methods with higher than O(n3) time complexity are used to deal with memory consistency verification. In this paper, a linear time complexity memory consistency verification tool LCHECK is introduced. In the multi-processor system which supports store atomicity, there must be a time order between two operations with disjoint execution periods: The former operation in time order must be observed by the latter operation. LCHECK localizes memory consistency verification based on time order. It infers edges of orders and checks correctness in bounded operations. LCHECK is used in the verification of an industrial CMP, Godson-3, and finds many bugs of memory subsystem of Godson-3.

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