I'm still playing with this MC
Now i want to count positive/negative numbers and 0's in a given array. In c, i did something like this and it worked perfectly:
int A[15], pos, neg, nul, i;
[...]
pos = 0;
neg = 0;
nul = 0;
for for (i = 0; i < 15; i++) {
if (A[i] > 0) {
pos++;
}
if (A[i] < 0) {
neg++;
}
if (A[i] == 0) {
nul++;
}
}
So, the next step is to make something similar but in assembly code, i was thinking about this:
RWM EQU $0
ROM EQU $C000
RESET EQU $FFFE
QUANTITY EQU 200
ORG RWM
POSITIVES RMB
NEGATIVES RMB
ZEROS RMB
ORG ROM
Main:
END BRA END
ARRAY DW 1,4,8,-87,0,0,1,4,5,8,7,4,4,1,-9
ORG RESET
DW Main
i'm a little confused right here because i would need to consider the worst cases, i mean: all are positive, or all negative or all zero. So, i should define variable sizes according to the information to be saved. I think the end of the array should be ARRAY + QUANTITY-1.
EDIT#1:
For this case i would like to obtain this output:
Since th ARRAY contains these elements:
1,4,8,-87,0,0,1,4,5,8,7,4,4,1,-9
I should get this output:
POSITIVES 11
NEGATIVES 2
ZEROS 2
But remember:
i must consider the worst cases, i.e: all are positive, or all negative or all zero
Another different case:
Suppose that i want to obtain the absolute values of all the elements that are stored in a specific array.
I can achieve that using 'C',i mean, i could perform something like this:
#include <stdio.h>
#include <math.h>
int absolute(int *array, int N);
int main()
{
int array[16] = {0,1,2,3,-4,5,6,7,-8,9,-10,11,12,13,14,20};
int ray[16];
int i;
for ( i = 0; i < 16; i++ )
ray[i]=absolute(array,16);
printf("the absolute value is %d\n", ray[i]);
return 0;
}
int absolute(int *array, int N)
{
int i;
for(i=0; i<N; i++)
if (array[i]<0)
array[i] = array[i] * (-1);
}
I tried to do that in assembly (using 68hc11 instructions)
RWM EQU $0
ROM EQU $C000
RESET EQU $FFFE
ORG RWM
ABSOLUTE RMB
ORG ROM
Start:
END BRA END
ARRAY DW 4,144,447,-14,-555,-1147
ORG RESET
DW Start
I want to store inside ABSOLUTE all the absolute elements from ARRAY
PS: i have not defined the size for ABSOLUTE
I would like to see these values inside ABSOLUTE:
4,144,447,14,555,1147 (UNSIGNED NUMBERS)
The definition of QUANTITY as 200 seems pointless in your example because you hard code your array so it has a known number of elements regardless of what QUANTITY says. It would be better to have the assembler define QUANTITY to the actual number of elements like shown below (but not used in my ASM11 based example).
RAM equ $0
ROM equ $C000
Vreset equ $FFFE
;*******************************************************************************
#ROM
;*******************************************************************************
org ROM
ARRAY dw 4,144,447,-14,-555,-1147
;QUANTITY equ *-ARRAY/2
;*******************************************************************************
#RAM
;*******************************************************************************
org RAM
absolute rmb ::ARRAY
zeros rmb 1
positives rmb 1
negatives rmb 1
;*******************************************************************************
#ROM
;*******************************************************************************
Start ldx #ARRAY ;X -> source
ldy #absolute ;Y -> destination
;-------------------------------------- ;initialize all counters to zero
clr zeros
clr positives
clr negatives
;--------------------------------------
Loop ldd ,x ;D = word to test
beq CountZero ;go count zero
bpl CountPositive ;go count positive number
;--------------------------------------
inc negatives ;count negative number
; negd ;make it positive (abs)
coma
comb
addd #1
bra Cont
;--------------------------------------
CountZero inc zeros
bra Cont
;--------------------------------------
CountPositive inc positives
; bra Cont
;--------------------------------------
Cont std ,y ;save absolute value
ldab #2 ;B = word size
abx ;X -> next word
aby ;Y -> next word
cpx #ARRAY+::ARRAY ;check for end of array
blo Loop ;repeat for all elements
bra *
org Vreset
dw Start
BTW, your C code is incorrect. I think you meant to write something like this:
#include <stdio.h>
#define SIZE 16
int absolute(int array[], int ray[], int N)
{
for (int i=0; i<N; i++)
ray[i] = array[i] * (array[i]<0?-1:1);
}
int main()
{
int array[SIZE] = {0,1,2,3,-4,5,6,7,-8,9,-10,11,12,13,14,20};
int ray[SIZE];
absolute(array,ray,SIZE);
for (int i = 0; i < SIZE; i++ )
printf("The absolute value of %3i is %3i\n", array[i],ray[i]);
return 0;
}