COMPSCI 2000 Computer Systems - Practical Assignment 5: Hack Assembly - Add, Substract, Multiply and Assembler
Practical Assignment 5
Assessment Overview
Task description:
Write Assembly programs to complete the tasks described below and an Assembler to convert those programs to Machine code. Doing so should help you to:
Understand how programs run at a low level.
Understand how programs efficiency can be affected at a low level.
Please post your questions on Piazza or ask during your workshop.
Your Task
You've built the computer, now it's time to start programming it!
Your task for this practical assignment is to write assembly programs for the Hack machine you've built.
1. Download this zip file containing the template and test files for this assignment.
2. Complete the ASM files and Assembler as described and as outlined below.
Testing Requirement
To help you develop, understand, and debug your own code you'll also need to write several test cases for each task.
These test cases will be manually reviewed after the assignment due date.
Marks for each task may be scaled down as much as 50% for poor/missing testing.
The Gradescope autograder will run your test cases and provide some basic feedback.
The additional resources section below includes basic instructions and guides on writing test cases. We also recommend asking your workshop supervisors for advice on testing if you're unsure.
Low level code can be especially prone to errors.
Part 1 - Basic Programs (4 points)
In this part you'll be familiarise yourself with Hack assembly by writing a basic arithmetic program.
You'll also need to write your own tests. Take a look at the sample test file provided to see how to write your own test cases.
Task 1.1 - Add and Subtract (4 points)
Write a program in Hack assembly to calculate Complete the code in AddSub.asm
Inputs:
R1 contains the value for R2 contains the value for R3 contains the value for
Outputs:
Write your final answer to R0
Part 2 - Conditionals & Loops (24 points) In this part you'll be writing more complex programs that involve jumps.
Task 2.1 - Absolute Value (8 points)
Write a program in Hack assembly to calculate the absolute value Complete the code in Abs.asm
Inputs:
R1 contains the number
Outputs:
Write your final answer to R0
Test Cases:
(https://en.wikipedia.org/wiki/Absolute_value) of a given number.
Write at least 3 test cases.
A sample test case is provided in Abs00.tst
Each test case should be in a file named AbsXX.tst where XX is a number starting at 01 . You should also submit any supporting files such as CMP files.
Your mark for this task may be scaled down for poor/missing testing.
Task 2.2 - Multiply (16 points)
Write a program in Hack assembly to multiply 2 numbers. Complete the code in Mult.asm
Inputs:
R1 contains the first number
R2 contains the second number Outputs:
Write your final answer to R0
Test Cases:
Write at least 5 test cases.
A sample test case is provided in Mult00.tst
Each test case should be in a file named MultXX.tst where XX is a number starting at 01 . You should also submit any supporting files such as CMP files.
Your mark for this task may be scaled down for poor/missing testing.
Part 3 - Arrays (28 points)
It's time to apply your knowledge of Memory to work with array data structures.
Your solutions to this part will also be evaluated on efficiency; number of instructions used, with bonus points available.
Task 3.1 - Array Largest (12 points)
Write a program in Hack assembly to calculate the largest value in a given array. Complete the code in ArrMax.asm
Inputs:
R1 contains the RAM address of the first element in the array
R2 contains the length of the array Outputs:
Write your final answer to R0
Efficiency:
Your code runs, but how efficient is it? Your code will be tested on a large data set to measure its performance compared to a basic solution. You will gain/lose as much as 2 points depending on the efficiency of your code.
Make sure you have a working solution before trying to optimise!
Task 3.2 - Array Sort (16 points)
Write a program in Hack assembly to sort a given array in-place in descending order (largest to smallest). You may implement any sorting algorithm but should aim for a complexity of O(n2) or better.
Complete the code in ArrSort.asm
Inputs:
R1 contains the RAM address of the first element in the array
R2 contains the length of the array Outputs:
Write your True (-1) to R0 when your program finishes.
The correctly sorted array should replace the original array in its location.
Part 4 - Assembler (24 points)
We've written programs in assembly, but do we understand how to convert those to machine code?
Using your preferred programming language (Python, C++ or Java) implement an assembler as described below. Template files are provided for each of these programming languages.
Download the Python version HERE Download the Java version HERE Download the C++ version HERE
You will need to complete the methods provided.
Submit your completed source and test files in the same directory as your files from Parts 1-3. Only submit files for 1 programming language.
Task 4.1 - Basic Machine Code Translator (12 points)
Write code to implement the basic parsing and translation of A and C instructions.
Use the provided template files in your preferred programming language Complete the following methods:
doSecondPass/generateMachineCode
parseInstructionType
parseInstructionDest
parseInstructionJump
parseInstructionComp
parseSymbol
translateDest
translateJump
translateComp
translateSymbol
You may add methods, but do not modify the provided method signatures
You do not need to implement the Symbol Table or L-instructions
Submit your completed source and test files in the same directory as your files from Parts 1-3. Only submit files for 1 programming language.
Task 4.2 - Full 2-Pass Assembler (12 points)
Write code to implement the first pass and Symbol Table.
Use the provided template files in your preferred programming language
Complete the SymbolTable class and doFirstPass methods, as well as updating the translateSymbol method. You may add methods, but do not modify the provided method signatures
Submit your completed source and test files in the same directory as your files from Parts 1-3.
Only submit files for 1 programming language.
