#include "bigint.h"
#include "bigintprivate.h"
.global BigInt_add
.code 32


BigInt_larger:
        cmp     r4, r3  @if (iLength1 > iLength2)
        movlt   r4, r3  @iLarger = iLength1;
        b BigInt_for1


BigInt_add:
        @program initials
        push    {r3, r4, r5, r6, r7, lr}
        ldr     r4, [r0]
        ldr     r3, [r1]
        b BigInt_larger
        cmp     r4, #0
        mov     lr, r4
        ble     exit1           @exit the program
        mov    r6, #0
        mov     r7, r2
        mov     r3, r6


BigInt_for1:
                cmp     r4, #0 @for (i = 0; i < iSumLength; i++)
        mov     lr, r4
        ble     exit1           @exit the loop
        movs    r6, #0
        mov     r7, r2
        mov     r3, r6

BigInt_for2:
        adds    r6, r6, #1              @i++
        ldr     r5, [r0, #4]!           @oAddend1->auiDigits[i]
        ldr     r4, [r1, #4]!           @oAddend2->auiDigits[i];
        add     r3, r3, r5              @uiSum += oAddend1->auiDigits[i];
        cmp     r5, r3                  @if (uiSum < oAddend1->auiDigits[i]
        movls   r5, #0                  @uiCarry = 0;
        movhi   r5, #1                  @uiCarry = 1;
        adds    r4, r3, r4              @uiSum += oAddend2->auiDigits[i];
        str     r4, [r7, #4]!
        movcc   r3, r5                  @oSum->auiDigits[i] = uiSum;
        movcs   r3, #1
        cmp     r6, lr                  @i < iSumLength
        bne     BigInt_for2             @new for loop iterration
        cmp r3, #1                      @if (uiCarry == 1)
        beq if1
exit1:
        str     lr, [r2]
        movs    r0, #1                  @return True
        pop     {r3, r4, r5, r6, r7, pc}        @exit
if1:
        cmp     lr, #32768              @if (iSumLength == MAX_DIGITS)
        beq     return_f                                @return FALSE;
        add     r1, r2, lr, lsl #2      @auiDigits[iSumLength]
        add     lr, lr, #1              @iSumLength++;
        str     r3, [r1, #4]            @oSum->auiDigits[iSumLength] = 1;
        str     lr, [r2]
        movs    r0, #1
        pop     {r3, r4, r5, r6, r7, pc}
return_f:
        movs    r0, #0                  @return FALSE;
        pop     {r3, r4, r5, r6, r7, pc}