Question

CSE/EEE230 Assignment11

Due Date

Thursday, April 25th, 5pm

Note: the lowest scored assignment will be dropped.

Important: This is an individual assignment. Please do not collaborate.

It must be submitted on-line (Blackboard).

No late assignment will be accepted

Minimal Submitted Files

You are required to turn in the following source file:

assignment11.s

Objectives:

-write assembly language programs to:
            -perform arithmetic on floating point numbers
            -use syscall operations to display floating point numbers and strings on the console window
            -use syscall operations to read floating point numbers from the keyboard.

Assignment Description:

Write a MIPS assembly language program that prompts for a user to enter how many floating point numbers to enter, then prompts to enter a series of floating point numbers and reads in numbers and store them in an array, then asks a user how many small numbers to print, and computes and prints them.

Consult the green sheet and the chapter 3 for assembly instructions for floating point numbers. Here is one instruction that you might use:

c.lt.s   $f2, $f4
bc1t   Label1

Here if the value in the register $f2 is less than the value in $f4, it jumps to the Label1. If it should jump when the value in the register $f2 is NOT less than the value in $f4, then it should be:

c.lt.s   $f2, $f4
bc1f   Label1

To load a single precision floating point number (instead of lw for an integer), you might use:

l.s   $f12, 0($t0)

To store a single precision floating point number (instead of sw for an integer), you might use:

s.s   $f12, 0($t0)

To assign a constant floating point number (instead of li for an integer), you might use:

li.s    $f12, 123.45

To copy a floating point number from one register to another (instead of move for an integer), you might use:

mov.s    $f10, $f12

The following shows the syscall numbers needed for this assignment.

System Call           System Call                           System Call
Number                  Operation                              Description

2                              print_float             $v0 = 2, $f12 = float number to be printed
4                              print_string           $v0 = 4, $a0 = address of beginning of ASCIIZ string
6                              read_float              $v0 = 6; user types a float number at keyboard; value is stored in $f0
8                              read_string            $v0 = 8; user types a string at keybd; addr of beginning of string is stored in $a0; len in $a1

------------------------------------------
C program will ask a user how many floating numbers will be entered,
then read floating point numbers and store them in an array.
Then it asks a user how many smallest numbers to print, then print that many smallest numbers.
-------------------------------------------
void main( )
 {
 int arraysize = 25;
 float array[arraysize];
 int i, j, howMany, howManySmall;
 float num, temp;
 
 printf("Specify how many numbers should be stored in the array (at most 25):\n");
 scanf("%d", &howMany);
 
 //The following loop reads in floating point numbers
 //and stores them into the array
 i = 0;
 while (i < arraysize && i < howMany)
   {
     printf("Enter a number:\n");
     
     //read an integer from a user input and store it in num
     scanf("%f", &num);
     
     array[i] = num;
     i++;
   }
     
 //Print out each number in the array
 printf("The original array contains the following:\n");
 i = 0;
 while (i < arraysize && i < howMany)
   {
     printf("%f\n", array[i]);
     i++;
   }
     
     
  printf("Specify how many small numbers to print:\n");
  scanf("%d", &howManySmall);
     
  int minIndex;
  for (i = 0; i < howManySmall && i < arraysize-1 && i < howMany; i++)
   {
     minIndex = i;
     for (j = i+1; j < arraysize && j < howMany; j++)
       {
         if (array[j] < array[minIndex])
           {
             minIndex = j;
           }
       }
     temp = array[i];
     array[i] = array[minIndex];
     array[minIndex] = temp;
     
     printf("The smallest #%d : %f\n", (i+1), array[i]);
   }

   return;
 }

Here are sample outputs (user input is in bold): -- note that you might get some rounding errors.

Specify how many numbers should be stored in the array (at most 25):
14
Enter a number:
3.2
Enter a number:
6.43
Enter a number:
-3.23
Enter a number:
4.3
Enter a number:
4.3
Enter a number:
-3.24
Enter a number:
-5.4
Enter a number:
3.2
Enter a number:
3.2
Enter a number:
5.1
Enter a number:
6.5
Enter a number:
8.8
Enter a number:
8.8
Enter a number:
9.9
The original array contains the following:
3.200000
6.430000
-3.230000
4.300000
4.300000
-3.240000
-5.400000
3.200000
3.200000
5.100000
6.500000
8.800000
8.800000
9.900000
Specify how many small numbers to print:
4
The smallest #1 : -5.400000
The smallest #2 : -3.240000
The smallest #3 : -3.230000
The smallest #4 : 3.200000

Answer 1

smallest.asm:

.data

string1:.asciiz "\nSpecify how many numbers should be stored in the array (at most 25):"
string2:.asciiz "\nThe original array contains the following:"
string3:.asciiz "\nSpecify how many small numbers to print:"
string4: .asciiz "\nThe smallest #"
string5: .asciiz "\nEnter a number:"
col: .asciiz " : "
newline: .asciiz "\n"
array: .float 40000
val:   .float 10000.00
.text
   li $t0,1
  
   l.s $f10,val
   la $t1, array
   li $v0,4
   la $a0,string1 #print string 1
   syscall  
  
  
   li $v0, 5
   syscall
   move $s0,$v0 #store user number of array elements
  
while:   bgt $t0,$s0,init
  
   li $v0,4
   la $a0,string5 #print string 5
   syscall  
   li $v0, 6 #gets user input floating point number and stores it into $f0
   syscall
   s.s $f0,0($t1) #store floating point number in array
   addi $t1,$t1,4
   addi $t0,$t0,1
   j while
  
  
init:   li $v0,4
   la $a0,string2 #print string 2
   syscall
   la $t1, array
   li $t0,1
  
print:   bgt $t0,$s0,final
   li $v0,4
   la $a0,newline #print new line
   syscall
  
   li $v0, 2         
   l.s $f12, ($t1)         #print array elements
   syscall  
   addi $t1,$t1,4
   addi $t0,$t0,1
   j print  
  
final:   li $v0,4
   la $a0,string3 #print string 3
   syscall
  
   li $v0, 5
   syscall
   move $s1,$v0 #store number of smallest elements to be printed
  
   li $t2,1
  
loop:   bgt $t2,$s1,end
   la $t1, array
   l.s $f6, ($t1)   #min
   li $t0,1  
in:   bgt $t0,$s0,brk
   l.s $f8,($t1)
   c.le.s $f8,$f6
   bc1t swap
   bc1f update
brk:   #add.s $f8,$f8,$f10
   s.s $f10,0($t7)  
   li $v0,4
   la $a0,string4 #print string 4
   syscall
  
   li $v0,1
   move $a0,$t2
   syscall
  
   li $v0,4
   la $a0,col #print colon
   syscall
  
   li $v0, 2         
   mov.s $f12,$f6         #print smallest element
   syscall  
   addi $t2,$t2,1
   j loop
update: addi $t1,$t1,4
   addi $t0,$t0,1
   j in  
swap:     mov.s $f6,$f8
   move $t7,$t1
   j update
end:   li $v0, 10#stop the program and exit
         syscall
        

Output:

Mars Messages Run /O ecify how many numbers should be stored in the array (at most 25):14 ter a number:3.2 nter a number:6.43 nter a number:-3.23 er a number:4.3 Clear

Mars Messages Run I/O ter a number:4.3 ter a number:-3.24 Clear Enter a number:-5.4 ter a number:3.2 ter a number:3.2

Mars Messages Run I/O ter a number:5.1 ter a number:6.5 ter a nunber:8.8 ter a number:8.8 ter a number:9.9 Clear

Mars Messages Run Vo If checked, will display line number for each line of text. The original array contains the following: 3.2 6.43 3.23 Clear 3.24 5.4 3.2

Mars Messages Run l/O 5 12.4 8 43.93 Clear Specify how many small numbers to print:4 e smallest #1 : -5.4 e smallest #2 : -3.24 e smallest #3 : -3.23 smallest #4 : 3.2