ReSlice: Selective Re-Execution of Long-Retired Misspeculated Instructions Using Forward Slicing

As more data value speculation mechanisms are being proposed to speed-up processors, there is growing pressure on the critical processor structures that must buffer the state of the speculative instructions. A scalable solution is to checkpoint the processor and retire speculative instructions. However, in this environment, misprediction recovery becomes very wasteful, as it involves discarding and re-executing all the instructions executed since the checkpoint. To speed-up execution in this environment, this paper presents a novel architecture (ReSlice) that selectively re-executes only the speculatively-retired instructions that directly depended on the mispredicted value, namely its Forward Slice. ReSlice buffers the (typically very few) instructions in the forward slice of the predicted value as such instructions initially execute. Then, potentially thousands of instructions later, ReSlice can quickly re-execute the slice if a misprediction is declared, and merge its state with th...

• Type: Conference
• Year: 2005
• Where: MICRO
• Authors: Smruti R. Sarangi, Wei Liu, Yuanyuan Zhou
• Keywords: Forward Slice, Hardware, MICRO 2005, Retire Speculative Instructions, Speculative Instructions