Hi, I am getting very low IPCs for PARSEC benchmarks, with serializing instructions being the main culprit. And I found from the discussion on the mailing list that scoreboarding HW_MFPR/HW_MTPR instructions could help with the low IPC problem. The IPR implementation in M5 is based on Alpha 21164 and scoreboarding was used in Alpha 21264. Basically in Alpha 21164 the IPR index was calculated from <15:0> bits but in Alpha 21264 <15:8> bits were used for IPR index and <7:0> bits were used for scoreboard mask. I think I will have to change the pal code and logic for handling IPR registers. So, I want to know if it is worthwhile to put effort in this direction ? Also, I do not see a correspondence in the IPR encodings in 21164 and 21264. For instance
ITB_TAG <15:0> bits in 21264 is 0000 0000 0100 0000 ITB_TAG <15:0> bits in 21164 is 0000 0001 0000 0001 Thanks, -- -Abhishek Graduate Student Computer Science University of Virginia --------------------------------------------------------------------------------------------------------------------- simplicity is the ultimate sophistication -Leonardo da Vinci
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