Consider the following MIPS code segment that is executed on a 5-stage pipeline architecture that does not implement forwarding or stalling in hardware. (1) add $4, $1, $1 (2) add $7, $4, $9 (3) lw $2, 40($8) (4) sub $8, $1, $2 (5) sw $8, 80($2) (6) sub $2, $8, $4 (7) lw $8, 2($1) (8) add $8, $4, $2 a. [6 marks] Identify the data dependences that cause hazards. You are to use the following format to inform each dependency reported: instruction (y) depends on instruction (z) caused by register $ b. [8 marks] If the hazards identified in (a.) are to be prevented by the compiler through no-op insertions but without reordering the instructions, indicate where would the compiler add no-ops. You are to use the following format to inform each dependency reported: insert x no-ops between instructions (y) and (z). c. [6 marks] Now assume a more intelligent compiler that can move instructions in the code. Can such a compiler reduce the number of added no-ops?

Ap practice - performance task response the ap create performance task asks you to write about an abstraction that you developed and wrote into your code. most of the time that means identifying a function or procedure you wrote to "manage complexity" in your program. here is the actual prompt from the create performance task: 2d. capture and paste a program code segment that contains an abstraction you developed individually on your own (marked with a rectangle). this abstraction must integrate mathematical and logical concepts. explain how your abstraction manage the complexity of your program. (must not exceed 200 words) below is a segment of code from an "under the sea" program with a rectangle drawn around a portion of the code identifying an abstraction. imagine that you wrote this and are composing an ap response about how this abstraction manages complexity. (note: ignore the requirement that the abstraction integrate "mathematical and logical concepts" for this practice response. just write about managing complexity). explain how the abstraction marked with the rectangle in the code above manage complexity of this program. write your response here submit

3. bob is arguing that if you use output feedback (ofb) mode twice in a row to encrypt a long message, m, using the same key each time, it will be more secure. explain why bob is wrong, no matter what encryption algorithm he is using for block encryption (15 points).

The great length of north america causes the climate to be varied. true false