Froyo  |  2.2_r1
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<title>iget&lt;kind&gt;</title>
<link rel=stylesheet href="opcode.css">
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<h1>iget&lt;kind&gt;</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 &amp; Format</th>
  <th>Mnemonic / Syntax</th>
  <th>Arguments</th>
</tr>
</thead>
<tbody>
<tr>
  <td>59..5f 22c</td>
  <td>i<i>instanceop</i> vA, vB, field@CCCC<br/>
    59: iput<br/>
    5a: iput-wide<br/>
    5b: iput-object<br/>
    5c: iput-boolean<br/>
    5d: iput-byte<br/>
    5e: iput-char<br/>
    5f: iput-short
  </td>
  <td><code>A:</code> source 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 stack frame.
  </li>
  <li>
    For the -wide variant, also A+1 must be a valid register index in the
    current stack frame.
  </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>
  <li>
    For the -object variant, the instance referenced by register vA must be
    assignment-compatible to the type of the field.
  </li>
</ul>

<h2>Behavior</h2>

<ul>
  <li>
    For all but the -wide variant, the value of register vA is move into the
    field, that is, &lt;object&gt;.&lt;field&gt;'=vA.
  </li>
  <li>
    For the -wide variant, the registers vA and v(A+1) are moved into the
    field as follows:
    <ul>
      <li>
        &lt;object&gt;.&lt;field&gt;' = vA &lt;&lt; 0x20 | v(A+1)
      </li>
    </ul>
  </li>
</ul>

<h2>Exceptions</h2>

<ul>
  <li>
    NullPointerException if vB=null.
  </li>
  <li>
    IllegalAccessException if &lt;object&gt;.&lt;field&gt; is not visible from
    the current context according to the usual visibility and access rules of
    the Java programming language, or final.
  </li>
</ul>

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