TRANSITIONING FROM INSTRUCTION CACHE TO TRACE CACHE ON LABEL BOUNDARIES

摘要

Various embodiments of methods and systems for implementing a microprocessor (100) that includes a trace cache (160) and attempts to transition fetching from instruction cache (106) to trace cache (160) only on label boundaries are disclosed. In one embodiment, a microprocessor (100) may include an instruction cache (106), a branch prediction unit (132), and a trace cache (160). The prefetch unit (108) may fetch instructions from the instruction cache (106) until the branch prediction unit (132) outputs a predicted target address for a branch instruction. When the branch prediction unit (132) outputs a predicted target address, the prefetch unit (108) may check for an entry (162) matching the predicted target address in the trace cache (160). If a match is found, the prefetch unit (108) may fetch one or more traces (166) from the trace cache (160) in lieu of fetching instructions from the instruction cache (106).