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{{Longword}} A '''{{Doc|package=RTL|unit=system|identifier=longword|text=<syntaxhighlight lang="delphi" inline>longWord</syntaxhighlight>}}''' is an unsigned integer data type which is ''larger'' than a [[Word|<syntaxhighlight lang="delphi" inline>word</syntaxhighlight>]].^{[https://www.gnu-pascal.de/gpc/LongWord.html]} Larger refers to both the permissible range of values and the [[SizeOf|size]] occupied in a [[Packed|<syntaxhighlight lang="pascal" inline>packed</syntaxhighlight>]] structure. == Definition == === GNU Pascal Compiler === In [[GNU Pascal]] a <syntaxhighlight lang="delphi" inline>longWord</syntaxhighlight> is compatible to GNU [[Pascal for C users|C]]’s {{Doc|package=RTL|unit=ctypes|identifier=culonglong|text=<syntaxhighlight lang="c" inline style="whitespace: nowrap;">long long unsigned int</syntaxhighlight>}}. On ''some'' platforms it is 64&nbsp;bits wide and thus has a range of <syntaxhighlight lang="pascal" inline>0..18446744073709551615</syntaxhighlight> (<math>\mathbb{Z} \cap \left[0, 2^{64}\right)</math>). === Free Pascal Compiler === For compatibility with [[Delphi]], the [[FPC]] ''always'' defines <syntaxhighlight lang="delphi" inline>longWord</syntaxhighlight> as a 32-bit quantity, thus it may assume a value in the range <syntaxhighlight lang="pascal" inline>0..4294967295</syntaxhighlight> (<math>\mathbb{Z} \cap \left[0, 2^{32}\right)</math>). The defunct [[Mode GPC|<syntaxhighlight lang="delphi" inline style="whitespace: nowrap;">{$mode GPC}</syntaxhighlight>]] [[Compiler Mode|compiler compatibility mode]] did not change this. In this definition, {{Doc|package=RTL|unit=system|identifier=dword|text=<syntaxhighlight lang="delphi" inline>dWord</syntaxhighlight>}} (double word) is an alias for <syntaxhighlight lang="delphi" inline>longWord</syntaxhighlight>. As of version 3.2.0 the data type [[Cardinal|<syntaxhighlight lang="delphi" inline>cardinal</syntaxhighlight>]] is an ''unconditional'' alias for <syntaxhighlight lang="delphi" inline>longWord</syntaxhighlight>. == Application == * Because the FPC’s definition is fixed in size, it is frequently used when defining the ''exact'' memory layout of [[Record|<syntaxhighlight lang="pascal" inline>record</syntaxhighlight>]] data types that will be passed to foreign language libraries. If the external library is written C, use of the {{Doc|package=RTL|unit=ctypes|text=<syntaxhighlight lang="delphi" inline>cTypes unit</syntaxhighlight>}} is recommended. * Likewise, the GPC guarantees compatibility of certain integer data types with GNU C.^{[https://www.gnu-pascal.de/gpc/Summary-of-Integer-Types.html]} For maximum range, the GPC also defines <syntaxhighlight lang="pascal" inline>longestWord</syntaxhighlight>. == See Also == * [[Longint|<syntaxhighlight lang="delphi" inline>longInt</syntaxhighlight>]] * {{Doc|package=RTL|unit=system|identifier=plongword|text=<syntaxhighlight lang="delphi" inline>pLongWord</syntaxhighlight>}} * {{Doc|package=RTL|unit=types|identifier=tlongworddynarray|text=<syntaxhighlight lang="delphi" inline>types.tLongWordDynArray</syntaxhighlight>}} {{Data types}}

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