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8    <title>callb - Boolean call</title>
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10  <body>
11    <h1>callb - Boolean call</h1>
12
13    <h2>Calling Format</h2>
14    <div class="section">
15      <pre class="definition">
16callb   src, label
17</pre>
18    </div>
19
20    <h2>Operands</h2>
21    <div class="section">
22      <table class="arguments">
23        <thead>
24          <tr>
25            <th>Name</th>
26            <td>Description</td>
27          </tr>
28        </thead>
29        <tr>
30          <th><CODE>src</CODE></th>
31          <td>
32            A Boolean register.<br>
33          </td>
34        </tr>
35        <tr>
36          <th>label</th>
37          <td>
38            Label name.<br>
39          </td>
40        </tr>
41      </table>
42    </div>
43
44    <h2>Overview</h2>
45    <div class="section">
46      <p>
47        Causes control to jump to the address of the specified label name when the specified Boolean register contains <CODE>true</CODE>.<br> Once code has been executed up to the <CODE>ret</CODE> instruction following the label address, execution will return to the address immediately after this instruction. You cannot call a label unless a <CODE>ret</CODE> instruction has been set for it.<br>
48      </p>
49      <p class="notice">
50        You can nest <CODE>call</CODE> instructions (<CODE>call</CODE>, <CODE>callc</CODE>, and <CODE>callb</CODE>) up to four times. Behavior is undefined if these are nested five or more times.<br> Behavior is also undefined when a nested <CODE>call</CODE> instruction is invoked immediately before a <CODE>ret</CODE> instruction.<br>
51      </p>
52    </div>
53
54    <h2>Operation</h2>
55    <div class="section">
56<pre class="definition">
57if ( src )
58    call    label
59</pre>
60    </div>
61
62    <h2>Code Example</h2>
63    <div class="section">
64<pre class="definition">
65callb   b0, subfunction0
66
67subfunction0:
68..
69ret
70</pre>
71    </div>
72
73
74  <h2>Revision History</h2>
75  <div class="section">
76    <dl class="history">
77      <dt>2011/12/20</dt>
78      <dd>Initial version.<br />
79      </dd>
80    </dl>
81  </div>
82
83  <hr><p>CONFIDENTIAL</p></body>
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