Migrating 32-bit Applications to 64-bit
Migration Steps

Longptr

In the 32-bit platform, longptr is the same as long; you can continue using long wherever longptr is required in 32-bit applications. In 64-bit applications, however, using long to hold longptr variables will lead to data truncation from 8 bytes to 4 bytes, or memory corruption if you pass a long ref variable when a longptr ref is required. If you want to migrate to 64-bit, use longptr wherever required as it does no harm to 32-bit.

Since PowerBuilder does not have a datatype corresponding to the C++ pointer type, and there are no pointer operations in PowerBuilder, longptr is not a full-fledged PowerBuilder datatype. You can use it to hold/pass window handles, database handles, and other objects that are essentially memory addresses. Doing complex operations on longptr type might not work. If you want to represent/compute 8-byte long integers, use longlong.

LongLong

To take advantage of the 64-bit architecture, you can change your Long datatype variables to LongLong. Because this datatype is for 64-bit signed integers, from -9223372036854775808 to 9223372036854775807.

Keep in mind that LongLong continues using literals as for integers, but longer numbers are permitted.

Using 1-byte structure member alignment in external function (read more)

When you use a structure or structure array as parameters to external function in the older versions of PowerBuilder, the structure member alignment was one byte. However, the default alignment is 8 bytes on Windows platform, which means that most (if not all) Windows standard APIs use this value to align arguments with structure members. This will cause a mismatch between Windows APIs and PB applications in PowerBuilder 12.5 and earlier versions. A well adopted solution to this issue was to add some bytes within PowerBuilder structures manually to fill those gaps. Such gap filling can be complex and error-prone if involving complex nested structures. And what is worse, this solution fails with the introduction of 64-bit application development in PowerBuilder because the number of bytes you have to fill may be different between 64-bit and 32-bit applications. This was the major reason to make this change in PowerBuilder. The default structure member alignment for Windows APIs and Visual C++ is now on an 8 byte boundary. The structure member alignment was changed to 8 bytes for both 64-bit and 32-bit applications. This was an intentional change so that you can now call Windows APIs easier and use the same code for both 64-bit and 32-bit applications.

Customers can switch to the old behavior in two ways:

progmapack(1) is 1-byte alignment, progmapack(8) is an 8-byte boundary (double-word) alignment. These settings only affect an external function declaration’s alignment usage.