UNIT64 - what is it?

SFSxOI · Post by **SFSxOI** » Fri Aug 01, 2008 1:08 pm

I've run into some stuff in the new API's for Vista I don't know how to represent in PureBasic. One of them is UNIT64.

What is UNIT64? How is it represented in PureBasic? Is UNIT64 a quad in PureBasic?

How would a constant something like this be represented:

Code: Select all

someconstant (0x00001ui64)

Simply like this?

Code: Select all

#someconstant = $00001

?????

ts-soft · Post by **ts-soft** » Fri Aug 01, 2008 1:30 pm

UNIT64? or UINT64?
UINT64 is a unsigned Quad, not available in PB, but you can use Quad, is
the same memory but not the same valuerange

Progi1984 · Post by **Progi1984** » Fri Aug 01, 2008 1:30 pm

UNIT64 must be replaced by UINT64;

Yes, it's a quad;

Reference : http://www.purebasic.fr/english/viewtop ... ght=uint64

SFSxOI · Post by **SFSxOI** » Fri Aug 01, 2008 2:02 pm

UNIT64, so that is a quad. Oki dokee then.

But what about the strange constant like: someconstant (0x00001ui64)

what is the ui64?

Thanks for your help

Kale · Post by **Kale** » Fri Aug 01, 2008 4:33 pm

SFSxOI wrote:what is the ui64?

The "i64" and "ui64" extensions are non-standard, Microsoft compiler specific extensions used for specifing 64bit integer constants.

SFSxOI · Post by **SFSxOI** » Fri Aug 01, 2008 6:42 pm

Kale wrote:
SFSxOI wrote:what is the ui64?
The "i64" and "ui64" extensions are non-standard, Microsoft compiler specific extensions used for specifing 64bit integer constants.

well, crap....I was in the progress of converting the managment portion of the Windows Filtering Platform API for Vista and Server 2008, for use with PureBasic. Was going pretty smooth for a bit, had some basic functions working too, then I encountered the 'ui64' thing. So...if its microsoft compiler specific...well...just Great!

gotta find some way to work around it.

Thanks Folks

jack · Post by **jack** » Sat Aug 02, 2008 2:40 am

SFSxOI I don't see the problem, 0x00001ui64 simply means that the hex value is a Quad.

Kale · Post by **Kale** » Sat Aug 02, 2008 11:32 am

jack wrote:SFSxOI I don't see the problem, 0x00001ui64 simply means that the hex value is a Quad.

The problem is it's unsigned. There is no problem storing a 64bit number but retrieving a meaningful value from the quad is a little tricky.

SFSxOI · Post by **SFSxOI** » Tue Feb 03, 2009 9:01 pm

I know this thread is a bit old, but rather then starting a new one for the same subject...

I'm just getting back to working on the Windows Filtering Platform API for Vista, had put it aside for a while. I can't figure out how to get a useful value from the ui64 thing. Any ideas anyone?

Kaeru Gaman · Post by **Kaeru Gaman** » Tue Feb 03, 2009 9:18 pm

a problem only occurs when the highest bit is set.

then, PB will interpret it as negative value.

so, when you need to check a uint64 value, you could e.g. check for the highest bit with
If Val < 0

depending on the case you need it, you should get from the documentation if the highest bit could be set by any chance.

declaring a function to use a uint64 does not mean that every value passed will have the highest bit set...

pdwyer · Post by **pdwyer** » Wed Feb 04, 2009 1:46 am

shifting will work differently too, the sign bit doesn't shift with the rest of the value (I don't think, something like that)

Kaeru Gaman · Post by **Kaeru Gaman** » Wed Feb 04, 2009 5:15 am

with shifting via PB the signbit remains set, iirc.
but you can call the asm command for unsigned shift.

anyhow, checking for single bits doesn't know any difference in signed or unsigned,
so checking a 64bit Flag register will work without problems.

I think the approach to deal with this will strongly depend on the purpose of this uint64 value.

pdwyer · Post by **pdwyer** » Wed Feb 04, 2009 6:01 am

what is the ASM command for unsigned shifting? that would be handy

Thalius · Post by **Thalius** » Wed Feb 04, 2009 2:45 pm

isnt the result of lpperformancecounter also a UINT64 ?

i found this on a quick google - maybe useful.

http://books.google.ch/books?id=avDkMnu ... 1-PA114,M1

Kaeru Gaman · Post by **Kaeru Gaman** » Wed Feb 04, 2009 4:00 pm

> what is the ASM command for unsigned shifting?

don't know by heart... read it in a topic here not long ago.

> isnt the result of lpperformancecounter also a UINT64 ?

for handling a counter, it is meaningless if you notate it signed or unsigned.
handling the overflow is almost the same.
tho I'm unsure right now, if an overflow of some 64bit counter even can occur within the next thousand years...