Adaptive test generation for functional coverage closure

A system comprising one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising:

• obtaining graph data representing a coverage dependency graph associated with a hardware design for an integrated circuit;
• and
• at each of a plurality of simulation cycles, performing operations comprising:
• obtaining a set of coverage statistics as of the simulation cycle;
• updating, using the coverage dependency graph and the coverage statistics, respective distribution constraints for one or more random variables in a set of random variables;
• after the updating, generating one or more test stimuli by, for each test stimulus, sampling a respective value for each of the random variables in the set of random variables based on the respective distribution constraints;
• and
• simulating a performance of the integrated circuit for each of the test stimuli.

One or more non-transitory computer storage media encoded with instructions that, when executed by one or more computers, cause the one or more computers to perform operations comprising:

• obtaining graph data representing a coverage dependency graph associated with a hardware design for an integrated circuit;
• and
• at each of a plurality of simulation cycles, performing operations comprising:
• obtaining a set of coverage statistics as of the simulation cycle;
• updating, using the coverage dependency graph and the coverage statistics, respective distribution constraints for one or more random variables in a set of random variables;
• after the updating, generating one or more test stimuli by, for each test stimulus, sampling a respective value for each of the random variables in the set of random variables based on the respective distribution constraints;
• and
• simulating a performance of the integrated circuit for each of the test stimuli.