Assume there is full forwarding. Indicate hazards and add NOP instructions to eliminate them.

In this exercise, we examine how data dependences affect execution in the basic 5-stage pipeline described in Section 4.5. Problems in this exercise refer to the following sequence of instructions:

5 stage pipeline described in Section 4.5

The same principles apply to processors where we pipeline instruction execution. MIPS instructions classically take five steps:
1. Fetch instruction from memory.
2. Read registers while decoding the instruction. The regular format of MIPS instructions allows reading and decoding to occur simultaneously.
3. Execute the operation or calculate an address.
4. Access an operand in data memory.
5. Write the result into a register.

a. b. Without Forwarding 250ps 180ps With Full Forwarding With ALU-ALU Forwarding Only 300ps 240ps 290ps 210ps