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##### Integer Types and Compatibility

If you care about ISO compliance, only use `Integer` and subranges of `Integer`.

Some of GPC's non-ISO integer types exist in Borland Pascal, too: `Byte`, `ShortInt`, `Word`, and `LongInt`. The sizes of these types, however, are not the same as in Borland Pascal. Even for `Byte` this is not guaranteed (while probable, though).

When designing GNU Pascal, we thought about compatibility to Borland Pascal. Since GNU Pascal is (at least) a 32-bit compiler, `Integer` must have (at least) 32 bits. But what to do with `Word`? Same size as `Integer` (like in BP) or 16 bits (like in BP)? We decided to make `Word` the “natural-sized” unsigned integer type, thus making it (at least) 32 bits wide. Similarly, we decided to give `LongInt` twice the size of `Integer` (like in BP) rather than making it 32 bits wide (like in BP). So `LongInt` has 64 bits, and `ShortInt` has 16 bits on the IA32 platform.

On the other hand, to increase compatibility to Borland Pascal and Delphi, GPC provides the alias name `Comp` for `LongInt` (64 bits on IA32) and `SmallInt` for `ShortInt` (16 bits on IA32). Note that BP treats `Comp` as a “real” type and allows assignments like `MyCompVar := 42.0`. Since we don't consider this a feature, GPC does not copy this behaviour.