五种执行机制下的指令级并行性

Execution Mechanisms and Instruction-level Parallelism

指令级并行性是保证处理器性能不断改进的重要途径.我们利用研制的S&S模拟系统,针对不同执行机制对八个基准程序中潜在指令级并行性存在、开发情况的影响,在多方面进行了定量分析,结果表明推测式执行和多控制流并行是充分挖掘出程序中潜在并行性的关键。

Using the System, we studied the parallelism in 8 programs and approach to utilize the exposed ILP(instruction-level parallelism) in a deep and thorough going way. We see that speculative execution can increase the average amount of single control - flow ILP to about 3 times,with branch prediction rate 85 %. And, for non-scientific programs,multiple control-flow mechanism can sustain in excess of 6 instructions per cycle(IPC);Further incorporating with speculative execution strategy ; IPCs of most programs are greater than 10. So, we believe that speculative execution and multi-control flows is the key to exploit the ILP.