MAPPING INSTRUCTION BLOCKS INTO INSTRUCTION WINDOWS BASED ON BLOCK SIZE

摘要

A processor core in an instruction block-based microarchitecture utilizes instruction blocks having headers including an index to a size table that may be expressed using one of memory, register, logic, or code stream. A control unit in the processor core determines how many instructions to fetch for a current instruction block for mapping into an instruction window based on the block size that is indicated from the size table. As instruction block sizes are often unevenly distributed for a given program, utilization of the size table enables more flexibility in matching instruction blocks to the sizes of available slots in the instruction window as compared to arrangements in which instruction blocks have a fixed sized or are sized with less granularity. Such flexibility may enable denser instruction packing which increases overall processing efficiency by reducing the number of nops (no operations, such as null functions) in a given instruction block.