My apologies if this has already been addressed.

The following



generates the following qwords:



It appears that FASM sign-extended the current address. This could lead to subtle bugs, breaks code that was written for the lower 2GB of address space when that code is assembled for the top half of memory, and it seems like it wouldn't work well for x86-64.

For instance, the construct:



Where foo is a label, works just fine when the foo is below 2GB, but generates an error when foo is above 2GB.

Priv, do you plan on changing this feature?

This is only because current fasm versions store "org" base address as 32-bit value. This has of course to be changed in the fasm version with 64-bit code generation. And with 32-bit code it shouldn't cause a problems, as you usually don't use 64-bit addresses in this mode.