type Comp = LongInt;
Comp is a signed integer type which is longer than Integer. On some platforms it is 64 bits wide and thus has a range of -9223372036854775808 .. 9223372036854775807.
There are lots of other integer types in GPC, see Integer Types.
Comp is a Borland Pascal extension.
In some contexts, Borland Pascal treats Comp as a “real” type – this behaviour is not supported by GPC.
program CompDemo; var a: Comp; begin a := 42; WriteLn (a) end.
Integer Types, Subrange Types.