LongWord

A longWord is an unsigned integer data type which is larger than a word.¹ Larger refers to both the permissible range of values and the size occupied in a packed structure.

Definition

GNU Pascal Compiler

In GNU Pascal a longWord is compatible to GNU C’s long long unsigned int. On some platforms it is 64 bits wide and thus has a range of 0..18446744073709551615 ($\mathbb{Z} \cap \left[0, 2^{64}\right)$).

Free Pascal Compiler

For compatibility with Delphi, the FPC always defines longWord as a 32-bit quantity, thus it may assume a value in the range 0..4294967295 ($\mathbb{Z} \cap \left[0, 2^{32}\right)$). The defunct {$mode GPC} compiler compatibility mode did not change this. In this definition, dWord (double word) is an alias for longWord. As of version 3.2.0 the data type cardinal is an unconditional alias for longWord.

Application

• Because the FPC’s definition is fixed in size, it is frequently used when defining the exact memory layout of record data types that will be passed to foreign language libraries. If the external library is written C, use of the cTypes unit is recommended.
• Likewise, the GPC guarantees compatibility of certain integer data types with GNU C.² For maximum range, the GPC also defines longestWord.

See Also

• longInt
• pLongWord
• types.tLongWordDynArray

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From the Free Pascal wiki, page "LongWord", as it stood on 2023-12-22 after a change by Alextpp, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's Licensing page. If you have concerns about this material, message the admin.