My 64-bit programming experience

[Patrice Terrier]

Since i am now programming in both 32 and 64-bit, there is something i would like to share with you about 64-bit.

While most of the common API structure TYPE are still the same in 64-bit, a few are using 8-byte alignment rather than 4-byte, causing major havoc if you are not aware of this.

While this is not a problem for those using C or C++, this could be much of an issue if ever there is a 64-bit version of PowerBASIC.

Let's take an example :

The BITMAP structure is using a size of 28-byte in 32-bit, but a size of 32-byte in 64.
This has a direct impact on the bm.bmBits pointer, especially when dealing with the GetObjectA API.
So always use first GetObjectA with a null pointer to retrieve the correct size to use, or your code won't work anymore and you will not understand why.

[Aslan Babakhanov]

Thank you Patrice!

[Patrice Terrier]

Aslan

Here is the TYPE i am using for BITMAP in 64-bit mode with another langage

BITMAP64 is structure
	bmType is int          //Type C : LONG
	bmWidth is int         //Type C : LONG
	bmHeight is int        //Type C : LONG
	bmWidthBytes is int    //Type C : LONG
	bmPlanes is 2-byte int //Type C : WORD
	bmBitsPixel is 2-byte int //Type C : WORD
	[COLOR="Red"][B]dummy is int[/B][/COLOR]           //add 4-byte for correct alignment in 64-bit
	bmBits is system int   //Type C : LPVOID
END

[Michael Mattias]

Isn't there some alignment/fill directive you can specify on the TYPE line?

Not that it matters with no PB/64 but I have to belive those interested in "someday" using a PB/64 would not box themselves in, opting to code something like..

#IF %SIXTY_FOUR
    TYPE BITMAP   alignment/fill option for 64
#ELSE
    TYPE BITMAP    32-bit values for same
#ENDIF
    member  
    member  
END TYPE 
#ENDIF

Ready to move when you are!

MCM

[James C Morgan]

interesting read

https://docs.microsoft.com/en-us/previous-versions/tn-archive/bb496995(v=technet.10)?redirectedfrom=MSDN