; Arguments:
; [Furthest from EBP]
;   1.  U32             Stepping
;   0.  U32             Affected Value
; [Nearest to EBP]
;
; Returns:
;   - EAX: The next higher multiple of the stepping,
;          as calculated from affected value.
ceil_to:
.prolog:
    push esi
    sub esp, 16

    mov esi, esp
    mov [esi + (16 - 4)], ecx
    mov [esi + (16 - 8)], edx
.check_values:
    mov eax, [ebp - 4]
    cmp eax, 0
    jne .affected_value_is_valid
    xor eax,  eax
    jmp .epilog
.affected_value_is_valid:
    mov ecx, [ebp - 8]
    cmp ecx, 0
    jne .calculate
    xor eax, eax
    jmp .epilog
.calculate:
    ; Calculate how much needs ot be added to the
    ; affected value for it to become a multiple of
    ; the stepping using the remainder part of the division.
    div ecx
    ; EDX now contains how much the affected value
    ; 'goes over' the last multiple of the stepping.

    ; Now, it can be calculated how much has to be added
    ; to the affected value to make it the next multiple
    ; of the stepping.
    mov ecx, [ebp - 8]
    sub ecx, edx

    mov eax, [ebp - 4]
    add eax, ecx
.epilog:
    mov edx, [esi + (16 - 8)]
    mov ecx, [esi + (16 - 4)]
    add esp, 16
    pop esi
    ret