Patent ID: 7984338

Claim:
A system comprising: a first processor configured to output a plurality of program counter (PC) trace records, wherein the plurality of PC trace records provide data indicating the PCs of instructions retired by the first processor; and a trace unit coupled to receive the plurality of PC trace records from the first processor, wherein the trace unit comprises a trace memory into which the trace unit is configured to store the plurality of PC trace records; and wherein each PC trace record includes an encoding that identifies a PC trace record type, wherein one encoding identifies the PC trace record as a loss recovery record which was generated in response to one or more PC trace records being dropped in a lossy trace mode, and wherein at least one other encoding identifies the PC trace record as a retire record which indicates successfully retired instructions including taken branches; and wherein the first processor is configured to output the loss recovery record, wherein the loss recovery record indicates the recovery PC at which tracing is recovered after the one or more dropped PC trace records.