Midterm Exam, CSCI 312, Spring 2011

• Make sure you answer each question completely and thoughtfully.
• Please make sure your answers are clearly labeled with the question number.
• Please write neatly and make any diagrams as neat as you can. If I can't read it, it is wrong.
• Point values are listed by each question.

1. (8 points) Name and describe the factors that influence a programs run time. This discussions should be related to the timing model discussed. (This is not a discussion about CPI, clock speed, ..., but these items should be part of the discussion)
2. (16 points) Describe and critique each of the following performance benchmarks:
   1. Clock Speed
   2. MIPS
   3. Execution time for a target program
   4. SPEC CPU Benchmark
3. (5 points each) A program running on a 2GHz processor has the following characteristics:

   	FP Inst	Int Inst	Load/Store Inst	Branch Inst
   Count	6x108	2 x 109	1x109	2x106
   CPI	5	1	3	2

   1. Calculate the CPI for this program on this processor.
   2. Calculate the time for this program on this processor.
4. (5 points) Represent the instruction addi $t5, $a0, -192 in MPIS as a 32 bit MIPS machine instruction.
5. (15 points) Label the diagram representing the DB-1 CPU. Describe (in approximately two sentences each) the function of all components of this machine.
6. (6 points) Describe the steps required to execute the instruction add R3, imm, R1 ( R[R3] ← M[imm] + R[R1]) in the simple (DB-1) CPU.
7. (5 points) How can a large instruction set be reduced in size. Give examples.
8. (10 points) Name and describe the major tasks accomplished by an assembler. When possible, give an example of the task as it relates to MIPS assembly language.