This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: that need no register writes; for these instructions the number of the destination register is simply a “random” choice between Rd or Rt). The MEM/WB register keeps the WB control signals, the value read from memory (or a “random” value if there was no memory read), the ALU result, and the number of the destination register. 4.20.2 Only RAW dependences can become data hazards. With forwarding, only RAW dependences from a load to the very next instruction become hazards. Without forwarding, any RAW dependence from an instruction to one of the following three instructions becomes a hazard: 2 4.21.2 We can move up an instruction by swapping its place with another instruction that has no dependences with it, so we can try to fill some nop slots with such instructions. We can also use R7 to eliminate WAW or WAR dependences so we can have more instructions to move up....
View Full Document
- Fall '09
- Trigraph, control signals, 16 bits, destination register, lowermost