Method and system using hardware assistance for instruction tracing by revealing executed opcode or instruction

摘要

A method, system, apparatus, and computer program product is presented for assisting instruction tracing operations. A mechanism is provided within the processor for revealing the most recently executed instruction. After the instruction is completed, the opcode of the instruction or the entire instruction is revealed in one of a variety of manners, such as by writing the opcode or instruction to a register that may be read by application-level code. Alternatively, a series of instructions may be stored in a trace buffer within the processor upon the completion of each instruction. In another alternative, the size and address of a trace buffer in memory may be placed into configuration registers, and a series of instructions may be stored in the trace buffer after the completion of each instruction. The tracing operation for the series of instructions may be qualified so that it is performed only in a taken-branch tracing mode.