The code in Part A has two data dependencies (R3 and R4), and can be resolved using forwarding and double-pumped register file. However, we still have control dependency for "beq" instruction. To solve the control dependency issue, we add a "nop" after the "beq" instruction, as showsn in Part B. Question: We would like to keep the pipeline full as much as possible and improve the performance. Can we reorder the instructions to avoid NOPs? If so, how?

For the whole question, pseudo-instructions are not allowed except “j target_label”and “jr ra”. One suggestion for assembly programming problems is that you can includecomments to one or a block of instructions. Consider a RISC-V assembly function func1. func1 has three passingarguments stored in registers a0, a1 and a2, uses temporary registers t0-t3 andsaved registers s4–s10. func1 needs to call func2 and other functions may call func1also. func2 has two passing arguments stored in registers a0 and a1, respectively. Infunc1, after the program returns to func1 from func2, the code needs the originalvalues stored in registers t1 and a0 before it calls func2. (a) How many words are the stack frames of function func1?(b) Indicate which registers are stored on the stack of func1.

In some instruction sets, call and return instructions make use of a RR register to hold the return address rather than doing so on the stack. Show how the code in the above problem should be changed if call and return instructions used a RR register for return addresses rather than the stack. Don't change the program's function. 500 MOV R1, X 501 MOV R2, Y 502 MOV R3, Z 503 PUSH R1 504 CALL 550 505 POP R3 506 CALL 560 507 HALT · · 550 PUSH R2 551 CALL 560 552 POP R2 553 RET · · 560 PUSH R3 561 PUSH R1 562 POP R2 563 POP R1 564 RET

How many trap service routines could theoretically be created for the LC-3, given the format of the TRAP instruction? (hint: how many bits are used for the trap vector?) 8 64 O 256 О 16к 32