Instructions
Please complete all the exercises below. Use the Venus RISC-V simulator to test your code. Note that
the simulator is 32-bit, and we do not consider overflow here.
Be sure to comment your code for clarity.
Once complete, upload your source code and PDF lab report on Sakai.
Exercises
1. [20 pts] Write a function in RISC-V that computes the following:
• When given a positive integer x as an input, return 10x using only add instructions.
• When given a negative integer y as an input, compute the opposite value (i.e. -y) without using
mul instructions.
Have a main function check the value of the input, perform the appropriate computations, and print
the output in the console. Note: you need to provide your own inputs and show screenshots of the
outputs based on the given inputs. (Each part worth 10 pts.)
2. [30 pts] Write a function exp in RISC-V that, when given a positive integer x, returns
x
5+6x3+3x+4. Your code should include the following:
• Write a main function to call the exp function and print the output in the console. [5 pts]
• Function exp will compute and return the expression. Function exp must call the following
additional functions: [10 pts]
o Call a power function to calculate x
n
. You may assume n will be positive. [10 pts]
o Call a times function to calculate n*x. [5 pts]
Note: you need to provide your own inputs and show screenshots of the outputs based on the given
inputs.
3. [50 pts] Write a function reorder in RISC-V that, when given an array {3, 7, 45, 66, 80,
1}, returns the array in reverse order (i.e. the first number is now the last). Your code should include
the following:
• Write a main function to perform the following tasks:
• Call an input function to write the given array values into a certain continuous memory
starting from 0(0x0fffffe8). Your input function should work for any sizes of the
array.
• Call the reorder function to reorder the array.
o Your function reorder must call a swap function to perform the necessary
operations to reorder two elements of the array.
• Call an output function to print the reordered array values in the console. Your output
function should work for any array size.
Note: you need to show screenshots of the outputs based on the given inputs.
(There are 5 functions in total, and each function worth 10pts.)