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<h3 class="section"><code>.word </code><var>expressions</var><code></code></h3>



   <p>This directive expects zero or more <var>expressions</var>, of any section,

separated by commas.



   <p>The size of the number emitted, and its byte order,

depend on what target computer the assembly is for.



   <blockquote>

<em>Warning: Special Treatment to support Compilers</em>

</blockquote>



   <p>Machines with a 32-bit address space, but that do less than 32-bit

addressing, require the following special treatment.  If the machine of

interest to you does 32-bit addressing (or doesn't require it;

see <a href="Machine-Dependencies.html#Machine%20Dependencies">Machine Dependencies</a>), you can ignore this issue.



   <p>In order to assemble compiler output into something that works,

<code>as</code> occasionally does strange things to <code>.word</code> directives. 

Directives of the form <code>.word sym1-sym2</code> are often emitted by

compilers as part of jump tables.  Therefore, when <code>as</code> assembles a

directive of the form <code>.word sym1-sym2</code>, and the difference between

<code>sym1</code> and <code>sym2</code> does not fit in 16 bits, <code>as</code>

creates a <dfn>secondary jump table</dfn>, immediately before the next label. 

This secondary jump table is preceded by a short-jump to the

first byte after the secondary table.  This short-jump prevents the flow

of control from accidentally falling into the new table.  Inside the

table is a long-jump to <code>sym2</code>.  The original <code>.word</code>

contains <code>sym1</code> minus the address of the long-jump to

<code>sym2</code>.



   <p>If there were several occurrences of <code>.word sym1-sym2</code> before the

secondary jump table, all of them are adjusted.  If there was a

<code>.word sym3-sym4</code>, that also did not fit in sixteen bits, a

long-jump to <code>sym4</code> is included in the secondary jump table,

and the <code>.word</code> directives are adjusted to contain <code>sym3</code>

minus the address of the long-jump to <code>sym4</code>; and so on, for as many

entries in the original jump table as necessary.



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