OpenEuphoria

RE: QWORD (int64) question

• Posted by Matthew Lewis <matthewwalkerlewis at YAHOO.COM> Oct 28, 2002
• 501 views

> From: Elliott Sales de Andrade [mailto:quantum_analyst at hotmail.com]

Sorry for the late reply (been out of town).

> Alright, one last set of questions. These QWORD's will, most 
> probably, be 
> signed. So, I'll guess that instead of the line:
>     ret = peek4u({q_fptr_retval, 2})
> I'd need to put:
>     ret = {peek4u(q_fptr_retval), peek4s(q_fptr_retval + 4)}
> to get {unsigned low dword, signed high dword}.
> And, last question,  how would i then put those two values 
> together, if I 
> needed to? I need to test for -1 values. Just multiplying the 
> high dword and 
> adding it to the low dword is good enough? Would that account for the 
> negative?

Getting the hi word signed should work fine.  Then you could just try:

if hi_word < 0 then
  lo_word = -lo_word
end if

qword = lo_word + hi_word * #100000000

Of course, make sure that qword is an atom.  If the numbers get too big, you
will lose some precision (after 15 decimal digits).

Matt Lewis