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| <h5 class="subsubsection">9.42.3.1 Using Density Instructions</h5> |
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| <p><a name="index-density-instructions-2019"></a> |
| The Xtensa instruction set has a code density option that provides |
| 16-bit versions of some of the most commonly used opcodes. Use of these |
| opcodes can significantly reduce code size. When possible, the |
| assembler automatically translates instructions from the core |
| Xtensa instruction set into equivalent instructions from the Xtensa code |
| density option. This translation can be disabled by using underscore |
| prefixes (see <a href="Xtensa-Opcodes.html#Xtensa-Opcodes">Opcode Names</a>), by using the |
| ‘<samp><span class="samp">--no-transform</span></samp>’ command-line option (see <a href="Xtensa-Options.html#Xtensa-Options">Command Line Options</a>), or by using the <code>no-transform</code> directive |
| (see <a href="Transform-Directive.html#Transform-Directive">transform</a>). |
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| <p>It is a good idea <em>not</em> to use the density instructions directly. |
| The assembler will automatically select dense instructions where |
| possible. If you later need to use an Xtensa processor without the code |
| density option, the same assembly code will then work without modification. |
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