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| Next: <a href="Code-Iterators.html#Code-Iterators" accesskey="n" rel="next">Code Iterators</a>, Up: <a href="Iterators.html#Iterators" accesskey="u" rel="up">Iterators</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p> |
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| <a name="Mode-Iterators-1"></a> |
| <h4 class="subsection">16.23.1 Mode Iterators</h4> |
| <a name="index-mode-iterators-in-_002emd-files"></a> |
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| <p>Ports often need to define similar patterns for two or more different modes. |
| For example: |
| </p> |
| <ul> |
| <li> If a processor has hardware support for both single and double |
| floating-point arithmetic, the <code>SFmode</code> patterns tend to be |
| very similar to the <code>DFmode</code> ones. |
| |
| </li><li> If a port uses <code>SImode</code> pointers in one configuration and |
| <code>DImode</code> pointers in another, it will usually have very similar |
| <code>SImode</code> and <code>DImode</code> patterns for manipulating pointers. |
| </li></ul> |
| |
| <p>Mode iterators allow several patterns to be instantiated from one |
| <samp>.md</samp> file template. They can be used with any type of |
| rtx-based construct, such as a <code>define_insn</code>, |
| <code>define_split</code>, or <code>define_peephole2</code>. |
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| <table class="menu" border="0" cellspacing="0"> |
| <tr><td align="left" valign="top">• <a href="Defining-Mode-Iterators.html#Defining-Mode-Iterators" accesskey="1">Defining Mode Iterators</a>:</td><td> </td><td align="left" valign="top">Defining a new mode iterator. |
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| <tr><td align="left" valign="top">• <a href="Substitutions.html#Substitutions" accesskey="2">Substitutions</a>:</td><td> </td><td align="left" valign="top">Combining mode iterators with substitutions |
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| <tr><td align="left" valign="top">• <a href="Examples.html#Examples" accesskey="3">Examples</a>:</td><td> </td><td align="left" valign="top">Examples |
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