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<h1>const</h1>
<h2>Purpose</h2>
<p>
Move the given literal value (sign-extended to 32 bits, if necessary) into the
specified register.
</p>
<h2>Details</h2>
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<th>Op & Format</th>
<th>Mnemonic / Syntax</th>
<th>Arguments</th>
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<td>12 11n</td>
<td>const/4 vA, #+B</td>
<td><code>A:</code> destination register (4 bits)<br/>
<code>B:</code> signed int (4 bits)</td>
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<td>13 21s</td>
<td>const/16 vAA, #+BBBB</td>
<td><code>A:</code> destination register (8 bits)<br/>
<code>B:</code> signed int (16 bits)</td>
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<td>14 31i</td>
<td>const vAA, #+BBBBBBBB</td>
<td><code>A:</code> destination register (8 bits)<br/>
<code>B:</code> arbitrary 32-bit constant</td>
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<td>15 21h</td>
<td>const/high16 vAA, #+BBBB0000</td>
<td><code>A:</code> destination register (8 bits)<br/>
<code>B:</code> signed int (16 bits)</td>
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<h2>Constraints</h2>
<ul>
<li>
A must be a valid register index in the current stackframe.
</li>
</ul>
<h2>Behavior</h2>
<ul>
<li>
First, an adjusted value B' is determined as follows:
<ul>
<li>
If we are executing the /high16 variant, then B is left-shifted by 16
bits, that is, B'=B << 0x10
<li>
Otherwise, if B is a 4 bit or 16 bit constant, it is sign-extended to 32
bits, that is, B'=sign-extended(B).
</li>
<li>
Otherwise, B'=B.
</li>
</ul>
<li>
Then, the adjusted value B' is moved into the register A, that is, vA'=B'
</li>
<li>
If v(A-1) is the lower half of a register pair, v(A-1)' becomes undefined.
</li>
<li>
If v(A+1) is the upper half of a register pair, v(A+1)' becomes undefined.
</li>
</ul>
<h2>Exceptions</h2>
<p>
None.
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