docs/opcodes/opcode-22-new-instance.html


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html>

<head>
<title>new-instance</title>
<link rel=stylesheet href="opcode.css">
</head>

<body>

<h1>new-instance</h1>

<h2>Purpose</h2>

<p>
Construct a new instance of the indicated type, storing a reference to it in the
destination. The type must refer to a non-array class.
</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>22 21c</td>
  <td>new-instance vAA, type@BBBB</td>
  <td><code>A:</code> destination register (8 bits)<br/>
    <code>B:</code> type index</td>
</tr>
</tbody>
</table>

<h2>Constraints</h2>

<ul>
  <li>
    A must be a valid register index for the current stack frame.
  </li>
  <li>
    B must be a valid index into the type pool.
  </li>
  <li>
    Type constant pool entry B must contain a valid type descriptor for a
    non-array class.
  </li>
</ul>

<h2>Behavior</h2>

<ul>
  <li>
    An attempt is made to get a reference to the class C the name of which is
    contained in type pool entry B.
  </li>
  <li>
    If C has not been loaded and resolved before, it is being loaded and
    resolved. All exceptions that are possible during class loading can occur at
    this point.
  </li>
  <li>
    An attempt is made to create a new instance I of C. All exceptions that are
    possible during instantiation can occur at this point.
  </li>
  <li>
    A reference to the new instance is stored in register vA, that is vA' = I.
  </li>
  <li>
    If v(A-1) is the lower part of a register pair, v(A-1)' becomes undefined.
  </li>
  <li>
    If v(A+1) is the upper part of a register pair, v(A+1)' becomes undefined.
  </li>
</ul>

<h2>Exceptions</h2>

<ul>
  <li>
    All exceptions that are possible during class loading can occur.
  </li>
  <li>
    All exceptions that are possible during instantiation can occur.
  </li>
</ul>

</body>
</html>