Cherry: checkpointed early resource recycling in out-of-order microprocessors

This paper presents CHeckpointed Early Resource RecYcling (Cherry), a hybrid mode of execution based on ROB and checkpointing that decouples resource recycling and instruction retirement. Resources are recycled early, resulting in a more efficient utilization. Cherry relies on state checkpointing and rollback to service exceptions for instructions whose resources have been recycled. Cherry leverages the ROB to (1) not require in-order execution as a fallback mechanism, (2) allow memory replay traps and branch mispredictions without rolling back to the Cherry checkpoint, and (3) quickly fall back to conventional out-of-order execution without rolling back to the checkpoint or flushing the pipeline. We present a Cherry implementation with early recycling at three different points of the execution engine: the load queue, the store

• Type: Conference
• Year: 2002
• Where: MICRO
• Authors: José F. Martínez, Jose Renau, Michael C. Huang, Milos Prvulovic, Josep Torrellas
• Keywords: Cherry, Cherry Checkpoint, Hardware, MICRO 2002, Resources