;
;     CPE 221 Assembly Example
;     
;     This program counts the number of negative and positive values in an 
;     array and stores them in neg_count and pos_count, respectively
;
        AREA   COUNT_NEG_POS, CODE, READONLY
        ENTRY            
        ADR       r10, nums              ; pointer to first element of array
        LDR       r1, size               ; holds size of array
        LDR       r2, i                ; i = 0
        LDR       r3, =0                ; neg = 0
        MOV    r4, #0               ; pos = 0
loop    CMP    r2, r1                ; Check to see whether i < size.
        BPL    store                    ; If not, done.
        ADD       r5, r10, r2, LSL #2    ; Add index to base array pointer.
        LDR    r5, [r5]                ; Load nums[i] into r5.
        ADD    r2, r2, #1            ; i++
        CMP    r5, #0                ; Set status bits
        ADDPL  r4, r4, #1            ; pos++
        ADDMI  r3, r3, #1             ; neg++
        B      loop                    ; Go back to loop.
store   STR    r3, neg
        STR    r4, pos
done    B      done
size    DCD    10
neg     SPACE  4
pos	    SPACE  4
i       DCD    0
nums    DCD    5, 3, -1, 2, 4, 37, -100, 13, -5, 0
        END