CS 3853 Spring 2010, Homework 5

1. Multiple Issue. Case Study Problems 2.3, 2.4, 2.5.
2. Register Renaming. Case Study Problem 2.9
3. Dynamic Scheduling
   • Optional Extra Credit: Case Study Problem 2.12 parts a through e.
   • (This part is not optional.) Do the following problem related to dynamic scheduling. Assume we have a MIPS machine that uses the speculative version of Tomasulo's algorithm. It can issue up to two instructions per clock cycle. Make the following assumptions about the machine:
     1. FP addition executes in 3 cycles
     2. FP multiplication executes in 5 cycles
     3. Integer operations and effective address addition execute in 1 cycle
     4. Data can be accessed in the data cache in 1 cycle
     5. The FPUs are fully pipelined and there are 2 FP adders (FA1,FA2), 1 FP multiplier (FM1)
     6. There are two ALUs (A1,A2), which handle effective address calculation along with all other integer operations.
     7. There are 8 entries in the reorder buffer
     8. The Issue and Commit columns of the table can handle up to two instructions (each) per cycle
     9. The CDB can handle up to two instructions per clock cycle
     10. At most one instruction may be accessing the data cache in each clock cycle
     11. The remaining FUs all have two reservation stations are, named: FMUL[1,2], FAD[1,2], ALU[1,2], ST[1,2], LD[1,2]
     Copy and fill in the following table indicating the cycles in which each instruction performs each step. Note that this table has been augmented to allow you to track the funtional unit, reservation station and ROB entry being used, which should ease your job of finding hazards. Notice that the FU/EX entry indicates what functional unit is performing computation for the instruction, and what cycles it begins on and ends on.

     Tomasulo Worksheet

     Instruction	Issue	ROB/ResStat	FU/EX	MEM	CDB	Commit
     L.D F1,0(R1)
     MUL.D F1,F1,F6
     L.D F2,0(R2)
     ADD.D F2,F2,F1
     S.D F2,0(R1)
     DADDIU R1,R1,#8
     DADDIU R2,R2,#8

Your assignment should be nicely typed or word-processed. Turn in this assignment at the beginning of class on April 26, 2010. You must turn in the assignment on paper at the beginning of class.

Late assignments will not be accepted.