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Converting Java to MIPS - User prompt displayed over and over again

mips java converting java list loop problems new

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3 replies to this topic

#1 flyntcoal

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Posted 27 September 2015 - 01:32 PM

To be honest, this isn't my first attempt to post and get help, but the other site decided to close my post because it wasn't a good enough question and because I decided to bump it. Be awesome if you could help me out, been trying to figure this out.

When I go to assemble and run the code, the program loops back up to the user prompt over and over again. I can only edit the Search section of the code. Basically the program should take the user input and tell where in the list the number that the is, if the number is in the list. When I ran it line by line, it went past the part it was stuck at, but it just printed the entire list. You will be considered awesome and get an internet high five from me. cheers.gif

Here is the MIPS Code: 

		.data
list:		.word 5
		.word 7
		.word 4
		.word 6
		.word 3
		.word 8
		.word 2
		.word 9
		.word 0
		.word 30
		.word 31
		.word 39
		.word 32
		.word 38
		.word 33
		.word 37
		.word 34
		.word 36
		.word 35
		.word 20
		.word 21
		.word 29
		.word 22
		.word 28
		.word 23
		.word 27
		.word 24
		.word 26
		.word 25
		.word 10
		.word 11
		.word 19
		.word 12
		.word 18
		.word 13
		.word 17
		.word 14
		.word 16
		.word 15
		.word 1			# last array element
		.word -1			# not part of array
prompt1:	.asciiz "\nPlease enter an array element: "
prompt2:	.asciiz "\nPlease enter a search target: "
space:	.asciiz " "
nfound:	.asciiz "\nThe target was not found."
found:	.asciiz "\nThe target was found at array location "

		.text
		.globl main
main:		add $t0, $zero, $zero	# [main]
		add $t1, $zero, $zero	#
		addi $t2, $zero, 39	#
		addi $t3, $zero, 39	#
		add $t4, $zero, $zero	#
		add $t5, $zero, $zero	#
		add $t6, $zero, $zero	#
#		add $t7, $zero, $zero	#
		la $t8, list

read:		addi $v0, $zero, 4	# [read]
		la $a0, prompt1		#
		syscall
		addi $v0, $zero, 5	#
		syscall
		sll $t7, $t0, 2		#
		add $t9, $t8, $t7
		sw $v0, 0($t9)
		addi $t0, $t0, 1		#
		ble $t0, $t2, read	#
		
# add the code that is missing from right here
		add $t0, $zero, $zero	#
		
search:		add $t1, $zero, $zero

search2:	lw $t4, 0($t9)
		lw $t5, 1($t9)
		sgt $t7, $t4, $t5
		sw $t4, 0($t9)
		sw $t5, 1($t9)
		add $t1, $t1, 1
		blt $t1, $t3, search2
		sub $t3, $t3, 1
		add $t0, $t0, 1
		blt $t0, $t2, search
		
print:		addi $v0, $zero, 1	# [print]
		sll $t7, $t0, 2		#
		add $t9, $t8, $t7
		lw $a0, 0($t9)
		syscall
		addi $v0, $zero, 4	#
		la $a0, space		#
		syscall
		addi $t0, $t0, 1		#
		ble $t0, $t2, print	#

end:		addi $v0, $zero, 10	# [end]
		syscall

Here is the Java Code:

	import java.io.*;
	
	public class CIS2233StarterCode2Java {
	
	public static void main (String [] args) throws IOException {
	
	BufferedReader kbd = new BufferedReader (new InputStreamReader (System.in));
	int [] list = {5,7,4,6,3,8,2,9,0,20,21,29,22,28,23,27,24,26,25,30,31,39,32,38,33,37,34,36,35,10,11,19,12,18,13,17,14,16,15,1};
	String prompt1 = "\nPlease enter an array element: ";
	String prompt2 = "\nPlease enter a search target: ";
	String space = " ";
	String nfound = "\nThe target was not found.";
	String found = "\nThe target was fount at array location ";
	int t0 = 0;
	int t1 = 0;
	int t2 = 39;
	int t3 = 39;
	int t4;
	int t5;
	int t6;
	int a0;
	int v0;
	// address calculation register t7
	// base address of array register t8
	// address calculation register t9
	do {
		System.out.print (prompt1);
		v0 = Integer.parseInt(kbd.readLine());
		list [t0] = v0;
		t0 ++;
	} while (t0 <= t2);
	t0 = 0;
	do {
		t1 = 0;
		do {
			t4 = list [t1];
			t5 = list [t1 + 1];
			if (t4 > t5) {
				list [t1 + 1] = t4;
				list [t1] = t5;
			}
			t1 ++;
		} while (t1 < t3);
		t3 --;
		t0 ++;
	} while (t0 < t2);
	t0 = 0;
	do {
		a0 = list [t0];
		System.out.print (a0);
		System.out.print (space);
		t0 ++;
	} while (t0 <= t2);
        }
        }


#2 flyntcoal

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Posted 27 September 2015 - 02:05 PM

narrowed it down to this line

		ble $t0, $t2, read	#

Edited by flyntcoal, 27 September 2015 - 02:10 PM.


#3 flyntcoal

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Posted 27 September 2015 - 03:00 PM

Never mind scratch that. Seriously just figured it out. The instructor made it so that the user has to enter 39 prompts. 
 
I have a new error though
 
Here is the updated MIPS Code
 
    .data
    list: .word 5
     .word 7
     .word 4
     .word 6
     .word 3
     .word 8
     .word 2
     .word 9
     .word 0
     .word 30
     .word 31
     .word 39
     .word 32
     .word 38
     .word 33
     .word 37
     .word 34
     .word 36
     .word 35
     .word 20
     .word 21
     .word 29
     .word 22
     .word 28
     .word 23
     .word 27
     .word 24
     .word 26
     .word 25
     .word 10
     .word 11
     .word 19
     .word 12
     .word 18
     .word 13
     .word 17
     .word 14
     .word 16
     .word 15
     .word 1 # last array element
     .word -1 # not part of array
    prompt1: .asciiz "\nPlease enter an array element: "
    prompt2: .asciiz "\nPlease enter a search target: "
    space: .asciiz " "
    nfound: .asciiz "\nThe target was not found."
    found: .asciiz "\nThe target was found at array location "
    
     .text
     .globl main
    main: add $t0, $zero, $zero # [main]
     add $t1, $zero, $zero #
     addi $t2, $zero, 1 #
     addi $t3, $zero, 39 #
     add $t4, $zero, $zero #
     add $t5, $zero, $zero #
     add $t6, $zero, $zero #
     add $t7, $zero, $zero #
     la $t8, list
    
    read: addi $v0, $zero, 4 # [read]
     la $a0, prompt1 #
     syscall
     addi $v0, $zero, 5 #
     syscall
     sll $t7, $t0, 2 #
     add $t9, $t8, $t7
     sw $v0, 0($t9)
     addi $t0, $t0, 1 #
     blt $t0, $t2, read #
     
     add $t0, $zero, $zero #
     
    search: add $t1, $zero, $zero
    
    search2: lw $t4, 0($t9)
     lw $t5, 1($t7)
     sgt $t7, $t4, $t5
     sw $t4, 0($t9)
     sw $t5, 1($t9)
     add $t1, $t1, 1
     blt $t1, $t3, search2
     sub $t3, $t3, 1
     add $t0, $t0, 1
     blt $t0, $t2, search
     
    print: addi $v0, $zero, 1 # [print]
     sll $t7, $t0, 2 #
     add $t9, $t8, $t7
     lw $a0, 0($t9)
     syscall
     addi $v0, $zero, 4 #
     la $a0, space #
     syscall
     addi $t0, $t0, 1 #
     ble $t0, $t2, print #
    
    end: addi $v0, $zero, 10 # [end]
     syscall
 
 
I am now getting an error message, so I have made a bit of progress.
Not quote sure what to make of this message I am getting with the runtime error saying : fetch address not aligned on word boundary 0x00000001

I should probably say it is on line 139
 
lw $t5, 1($t7)

how do i say this in MIPS?
 
t5 = list [t1 + 1];


#4 dargueta

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Posted 29 September 2015 - 02:49 AM

This means you're trying to read a word from an address that isn't a multiple of four. You forgot to multiply by four because that's how many bytes an integer takes up. Java does this for you behind your back, MIPS does not. Thus:

t5 = list[0] === lw $t5, ($t7)
t5 = list[1] === lw $t5, 4($t7)
t5 = list[2] === lw $t5, 8($t7)
t5 = list[3] === lw $t5, 12($t7)

Does this make sense?


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