;
;	CPE 221 Assembly Example
;	
;	This program finds the number with the maximum absolute value in an array
;
;       #include <iostream>
;       using namespace std;
;
;       int main()
;       {
;         const int size = 10;
;         int max;
;         int nums[size] = {100, 3, -1, 2, 4, 37, -100, 13, -5, 0};
;         int temp;
;         int i = 0;
;         max = nums[0];
;         if (max < 0)
;           max = -max;
;         for (i = 1; i < size; i++)
;         {
;           temp = nums[i];
;           if (temp < 0)
;             temp = -temp;
;           if (temp > max)
;             max = temp;
;         }
;       }   

		.org	200
size:		.equ	10
aamax:		.dw	1
array:	.dc	5, 3, -1, 2, 4, 37, -100, 13, -5, 0
orig:		.org	1000
		la	r30, done
		la	r29, loop
		la	r28, inc
                la      r27, pos2
                la      r26, pos1

		lar	r10, array		; pointer to first element of array
		la	r1, size		; holds size of array
		ld	r2, 0(r10)		; max = num[0]
                brpl    r26, r2                 ; If r2 > 0 jump to pos1
                neg     r2, r2                  ; r2 = -r2
pos1:		la	r4, 1			; r4 = 1, index1 into array

loop:		sub	r5, r4, r1		; Check to see whether index < size.
		brpl	r30, r5		        ; If not, done.
		shl	r6, r4, 2		; Multiply index by 4 to access entry 
						; in array by byte address.
		add	r6, r6, r10		; Add index to base array pointer.
		ld	r7, 0(r6)		; Load array[index] into r7.
                brpl    r27, r7                 ; If array[index] > 0 jump to pos2
                neg     r7, r7                  ; r7 = -r7
pos2:		sub	r8, r7, r2              ; test to see whether r7 is greater than r2
		brmi	r28, r8                 ; If not, go to i++       
            	addi	r2, r7, 0               ; r2 gets new max
inc:		addi	r4, r4, 1               ; i++
		br	r29                     ; Go to next iteration of the loop
done:		st	r2, amax                ; store computed max into variable
		stop