Reorder Buffer Simulation

Interactive Out-of-Order Execution with Precise Interrupts

How to Use This Simulator

Key Concepts:

  • ROB States: Issue → Execute → Complete → Commit
  • Register Renaming: RAT maps registers to ROB entries
  • Out-of-Order Execution: Instructions complete when ready
  • In-Order Commit: Results written in program order
  • Precise Interrupts: Exact program state maintained

Instructions:

  1. Load sample programs or write custom assembly
  2. Click "Load Program" to parse instructions
  3. Use "Step" for cycle-by-cycle execution
  4. Use "Run" for continuous execution
  5. Watch ROB entries and register renaming
  6. Observe commit order vs execution order

Instruction Input

Select a sample, click Load, then press "Load Program" below to parse.

Simulation Control

Delay: 1000ms per cycle

Test precise interrupt handling

Performance Metrics

Instructions Issued: 0
Instructions Completed: 0
Instructions Committed: 0
ROB Utilization: 0%
Average CPI: -
Total Cycles: 0
0%

Reorder Buffer Occupancy

Instruction Queue

No instructions loaded

Reorder Buffer (ROB)

Entry Instruction State Destination Value Exception

Register Alias Table

Reg ROB# Value

Instruction Execution Timeline

Start simulation to see execution timeline

Commit Log

No instructions committed yet