Abstract

Aggressive program optimization requires accurate profile information, but such accuracy requires many samples to be collected. We explore a novel profiling architecture that reduces the overhead of collecting each sample by including a programmable co-processor that analyzes a stream of profile samples generated by a microprocessor. From this stream of samples, the co-processor can detect correlations between instructions (e.g., memory dependence profiling) as well as those between different dynamic instances of the same instruction (e.g., value profiling). The profiler's programmable nature allows a broad range of data to be extracted, post-processed, and formatted, as well as provides the flexibility to tailor the profiling application to the program under test. Because the co-processor is specialized for profiling, it can execute profiling applications more efficiently than a general-purpose processor. The co-processor should not significantly impact the cost or performance of the ...

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