CSC231 Homework 6 2014

--D. Thiebaut (talk) 18:42, 4 November 2014 (EST)

---

This homework assignment is due on Tuesday, Nov 11, at 11:55 p.m.

Note: All problems are similar to the problems of Homework 5, with the exception of a few important details:

• All the functions must return their result in the stack, and not eax.
• All the functions must save all the registers they modify.
• The functions that compute the sum of the series x + (x-1) + (x-2) + ... + 2 + 1 must do so recursively.

Problem #1

Write a program called Hw6_1.asm that contains 1 function called f1 that will compute f1( x ) = (3 * x) - 1, and returns the result in the stack.

Your program cannot contain a main program with a label _start. You have to create your own main program to test your function.

Your function cannot modify any of the registers.

You only submit Hw6_1.asm to Moodle, and keep your test program.

Problem #2

Write a program called Hw6_2.asm that contains 1 function called f2 that computes f2( x ) = x + (x-1) + (x-2) + ... + 2 + 1, and returns the result in eax. We assume that x will always be strictly positive, and your function does not have to deal with negative numbers.
Examples:

f(1) = 1
f(2) = 2+1 = 3
f(3) = 3+2+1 = 6
f(4) = 4+3+2+1 = 10
f(5) = 5+4+3+2+1 = 15
etc.

Your function cannot modify any of the registers besides eax.

Submit your Hw6_2.asm program to Moodle, and keep your test program.

Problem #3

Write a program called Hw6_3.asm that contains 2 functions, f3 and f4, defined as follows:

• f3( x, y ) = 2 x + 3 y
• f4( x ) = 3 f3( x, 3 ) + f3( x-1, x+1 )

Your functions cannot modify any of the registers besides eax. for f3, x is pushed first, then y, when the function is called

Submit your program to Moodle, and keep your test program.

Problem #4

Write a program called Hw6_4.asm that contains 2 functions, f5, and f6, defined as follows:

• f5( x ) = x + (x-1) + (x-2) + ... + 2 + 1
• f6( x ) = f5( x ) + f5( x-1 ) + f5( x-2 ) + ... + f5( 2 ) + f5( 1 )

Your functions cannot modify any of the registers besides eax.

Submit your Hw6_4.asm program to Moodle, and keep your test program.

Testing & Verifying with Python

If you implement the functions in Python and test them for specific values, this is what they output:

f1( 3 ) = 8
f2( 10 ) = 55
f3( 5, 7 ) = 31
f4( 5 ) = 83
f5( 10 ) = 55
f6( 5 ) = 35