Description
Part A: Global Variables and Separate Compilation
A LIFO stack data structure can be implemented using an array, as shown in the following C program:
#include <stdio.h>
#include <stdlib.h>
#define STACKSIZE 5
#define FALSE 0
#define TRUE 1
/* Function Prototypes */
void push(int value);
int pop();
int stackFull();
int stackEmpty();
void display();
/* Global Variables */
int stack[STACKSIZE];
int top = -1;
int main()
{
int operation, value;
do {
system(“clear”);
printf(“### Stack Operations ###\n\n”);
printf(“Press 1 – Push, 2 – Pop, 3 – Display, 4 – Exit\n”);
printf(“Your option? “);
scanf(“%d”, &operation);
switch (operation) {
case 1:
printf(“\nEnter the positive integer value to be pushed: “);
scanf(“%d”, &value);
push(value);
break;
case 2:
value = pop();
if (value != -1)
printf(“\nPopped value is %d\n”, value);
break;
case 3:
display();
break;
case 4:
printf(“\nTerminating program\n”);
exit(0);
default:
printf(“\nInvalid option! Try again.\n”);
break;
}
printf(“\nPress the return key to continue . . . “);
getchar();
getchar();
} while (operation != 4);
return 0;
}
void push(int value)
{
if (stackFull())
printf(“\nStack overflow! Cannot push value onto stack.\n”);
else {
stack[++top] = value;
}
}
int pop()
{
register int value;
if (stackEmpty()) {
printf(“\nStack underflow! Cannot pop an empty stack.\n”);
return (-1);
} else {
value = stack[top];
top–;
return value;
}
}
int stackFull()
{
if (top == STACKSIZE – 1)
return TRUE;
else
return FALSE;
}
int stackEmpty()
{
if (top == -1)
return TRUE;
else
return FALSE;
}
void display()
{
register int i;
if (stackEmpty())
printf(“\nEmpty stack\n”);
else {
printf(“\nCurrent stack contents:\n”);
for (i = top; i >= 0; i–) {
printf(” %d”, stack[i]);
if (i == top) {
printf(” <– top of stack”);
}
printf(“\n”);
}
}
}
Translate all functions except main() into ARMv8 assembly language, and put them into a separate
assembly source code file called a5a.asm. These functions will be called from the main() function given
above, which will be in its own C source code file called a5aMain.c. Also move the global variables into
a5a.asm. Your assembly functions will call the printf() library routine. Be sure to handle the global
variables and format strings in the appropriate way. Input will come from standard input. Run the program
to show that it is working as expected, capturing its output using the script UNIX command, and name the
output file script1.txt.
Part B: External Pointer Arrays and Command-Line Arguments
Given the following declarations in C:
char *month[] = {“January”, “February”, “March”, “April”, “May”,
“June”, “July”, “August”, “September”, “October”,
“November”, “December”};
char *season[] = {“Winter”, “Spring”, “Summer”, “Fall”};
create an ARMv8 assembly language program to accept as command line arguments two strings
representing a date in the format mm dd. Your program will print the name of month, the day (with the
appropriate suffix), and the season for this date. For example:
./a5b 12 25
December 25th is Winter
Be sure to use the proper suffix for the day of the month. For example, one should distinguish the 11th
from the 1st, 21st, and 31st. Your program should exit, printing this error message, if the user does not
supply two command-line arguments:
usage: a5b mm dd
You will need to call atoi() to convert strings to numbers, and printf() to produce the output. Be sure to do
range checking for the day and month. Assume that Winter ranges from December 21 to March 20, Spring
from March 21 to June 20, Summer from June 21 to September 20, and Fall from September 21 to
December 20. Name your source code file a5b.asm. Run your program three times with different input to
illustrate that it works; capture the output using the script UNIX command. Name the output file script2.txt.
New Skills need for this Assignment:
Understanding and use of external variables in assembly
Separate compilation
Calling assembly functions from main()
Calling library functions from assembly routines
External arrays of pointers
Command line arguments
Submit the following:
1. Your source code and 2 scripts via electronic submission. Use the Assignment 5 Dropbox Folder in
D2L to submit electronically. Your TA will assemble and run your programs to test them. Name your
files a5aMain.c and a5a.asm for Part A, and a5b.asm for Part B, and the scripts as script1.txt and
script2.txt.
Computing Machinery I
Assignment 5 Grading
Student:__________________________________________
Part A:
Correct use of external variable(s) 4 ______
push() function in assembly 4 ______
pop() function in assembly 4 ______
stackFull() function in assembly 4 ______
stackEmpty() function in assembly 4 ______
display() function in assembly 8 ______
Linking of separate source code modules 2 ______
Correct manipulation of stack 4 ______
Part B:
Command line arguments 4 ______
Correct use of external pointer arrays 4 ______
Calls to library functions 2 ______
Range checking 3 ______
Correct output 4 ______
2 Scripts showing I/O 4 ______
Complete documentation and commenting 4 ______
Design quality 4 ______
Total 63 ______ _____%
