64bitised

64bitised is a term used to describe the process of converting software, systems, or data to operate on 64-bit computing architectures. It typically involves enabling 64-bit pointers and integers, enlarging the addressable memory space, and adjusting code to accommodate the LP64 or LLP64 data models used by target platforms such as x86-64, ARM64, or others.

It can include recompiling source code with a 64-bit compiler, porting a program to a 64-bit ABI, updating data structures to use appropriate sizes for types such as long and pointers, and replacing or rebuilding third-party libraries. Some 64-bit transitions also rely on compatibility layers or emulation when 64-bit native execution is not feasible. Important considerations include differences in structure packing, endianness, and calling conventions, which can affect binary compatibility and require changes in code, build systems, and tests.

64bitisation often enables access to more memory and can improve performance on memory-intensive workloads, though benefits are workload-dependent. It poses challenges such as maintaining cross-platform compatibility, ensuring accurate size and alignment of data structures, and managing legacy dependencies. In practice, many operating systems and software ecosystems undertake 64-bit ports as part of modernization, with major transitions historically seen in the move from 32-bit to 64-bit Windows, Linux, and macOS environments.