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<title>iget<kind></title>
<link rel=stylesheet href="opcode.css">
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<h1>iget<kind></h1>
<h2>Purpose</h2>
<p>
Perform the identified object instance field operation with the identified
field, loading or storing into the value register.
</p>
<p>
Note: These opcodes are reasonable candidates for static linking, altering the
field argument to be a more direct offset.
</p>
<h2>Details</h2>
<table class="instruc">
<thead>
<tr>
<th>Op & Format</th>
<th>Mnemonic / Syntax</th>
<th>Arguments</th>
</tr>
</thead>
<tbody>
<tr>
<td>52..58 22c</td>
<td>i<i>instanceop</i> vA, vB, field@CCCC<br/>
52: iget<br/>
53: iget-wide<br/>
54: iget-object<br/>
55: iget-boolean<br/>
56: iget-byte<br/>
57: iget-char<br/>
58: iget-short<br/>
</td>
<td><code>A:</code> dest value register or pair; (4 bits)<br/>
<code>B:</code> object register (4 bits)<br/>
<code>C:</code> instance field reference index (16 bits)</td>
</tr>
</tbody>
</table>
<h2>Constraints</h2>
<ul>
<li>
A and B must be valid register indices in the current stackframe.
</li>
<li>
For the -wide variant, also A+1 must be a valid register index in the
current stackframe.
</li>
<li>
Register vB must contain an object reference.
</li>
<li>
C must be a valid index into the field reference pool.
</li>
<li>
The field must be an instance field. The type of the field denoted by C must
match the variant of the instruction.
</li>
</ul>
<h2>Behavior</h2>
<ul>
<li>
The value of the given instance field is read from the given object and
moved into the given register vA, that is, vA'=<object>.<field>.
</li>
<li>
If v(A-1) is the lower half of a register pair, v(A-1)' becomes undefined.
</li>
<li>For all but the -wide variant, if v(A+1) is the upper half of a register
pair, v(A+1)' becomes undefined.
</li>
<li>
For the -wide variant, if v(A+2) is the upper half of a register pair,
v(A+2)' becomes undefined.
</li>
</ul>
<h2>Exceptions</h2>
<ul>
<li>
NullPointerException if object is null.
</li>
<li>
IllegalAccessException if <object>.<field> is not visible from
the current context according to the usual visibility and access rules of
the Java programming language.
</li>
</ul>
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