instructions2.doc3.html

A Java virtual machine instruction consists of an opcode specifying the operation to be performed, f

 

</Table><br></blockquote><p>
<a name="dup.Forms"></a>
<p><b>Forms</b><br>
<blockquote><a name="67790"></a>
<i>dup</i> = 89 (0x59)</blockquote><p>
<a name="dup.Operand"></a>
<p><b>Operand Stack</b><br>
<blockquote><a name="67791"></a>
..., <i>value</i> <img src="chars/arrwdbrt.gif"> ..., <i>value</i>, <i>value</i></blockquote><p>
<a name="dup.Description"></a>
<p><b>Description</b><br>
<blockquote><a name="67792"></a>
Duplicate the top value on the operand stack and push the duplicated value onto the operand stack. </blockquote><p>
<blockquote><a name="67793"></a>
The <i>dup</i> instruction must not be used unless <i>value</i> is a value of a category 1 computational type <a href="Overview.doc.html#7565">(&#167;3.11.1)</a>.</blockquote><p>

<a name="dup_x1"></a>
<hr><h2>dup_x1</h2>
<a name="dup_x1.Operation"></a>
<p><b>Operation</b><br>
<blockquote><a name="67804"></a>
Duplicate the top operand stack value and insert two values down<p><Table Border="1">
</blockquote>

<p><b>Format</b><br>
<blockquote>

<tr><td><a name="67803"></a>
 <i>dup_x1</i>
<td><a name="87568"></a>
 

</Table><br></blockquote><p>
<a name="dup_x1.Forms"></a>
<p><b>Forms</b><br>
<blockquote><a name="67805"></a>
<i>dup_x1</i> = 90 (0x5a)</blockquote><p>
<a name="dup_x1.Operand"></a>
<p><b>Operand Stack</b><br>
<blockquote><a name="87856"></a>
..., <i>value2</i>, <i>value1</i> <img src="chars/arrwdbrt.gif"> ...<em>, </em><i>value1</i>, <i>value2</i>, <i>value1</i></blockquote><p>
<a name="dup_x1.Description"></a>
<p><b>Description</b><br>
<blockquote><a name="67807"></a>
Duplicate the top value on the operand stack and insert the duplicated value two values down in the operand stack. </blockquote><p>
<blockquote><a name="67808"></a>
The <i>dup_x1</i> instruction must not be used unless both <i>value1</i> and <i>value2</i> are values of a category 1 computational type <a href="Overview.doc.html#7565">(&#167;3.11.1)</a>.</blockquote><p>

<a name="dup_x2"></a>
<hr><h2>dup_x2</h2>
<a name="dup_x2.Operation"></a>
<p><b>Operation</b><br>
<blockquote><a name="67819"></a>
Duplicate the top operand stack value and insert two or three values down<p><Table Border="1">
</blockquote>

<p><b>Format</b><br>
<blockquote>

<tr><td><a name="67818"></a>
 <i>dup_x2</i>
<td><a name="87568"></a>
 

</Table><br></blockquote><p>
<a name="dup_x2.Forms"></a>
<p><b>Forms</b><br>
<blockquote><a name="67820"></a>
<i>dup_x2</i><em> </em>= 91 (0x5b)</blockquote><p>
<a name="dup_x2.Operand"></a>
<p><b>Operand Stack</b><br>
<blockquote><a name="67821"></a>
Form 1:</blockquote><p>
<blockquote><a name="360371"></a>
..., <i>value3</i>, <i>value2</i>, <i>value1</i> <img src="chars/arrwdbrt.gif"> ...<em>, </em><i>value1</i>, <i>value3</i>, <i>value2</i>, <i>value1</i></blockquote><p>
<blockquote><a name="349837"></a>
where <i>value1</i>, <i>value2</i>, and <i>value3</i> are all values of a category 1 computational type <a href="Overview.doc.html#7565">(&#167;3.11.1)</a>.</blockquote><p>
<blockquote><a name="360368"></a>
Form 2:</blockquote><p>
<a name="dup_x2."></a>
<blockquote><a name="349841"></a>
..., <i>value2</i>, <i>value1</i> <img src="chars/arrwdbrt.gif"> ...<em>, </em><i>value1</i>, <i>value2</i>, <i>value1</i></blockquote><p>
<blockquote><a name="360367"></a>
where <i>value1</i> is a value of a category 1 computational type and <i>value2</i> is a value of a category 2 computational type <a href="Overview.doc.html#7565">(&#167;3.11.1)</a>.</blockquote><p>
<a name="dup_x2.Description"></a>
<p><b>Description</b><br>
<blockquote><a name="67822"></a>
Duplicate the top value on the operand stack and insert the duplicated value two or three values down in the operand stack. </blockquote><p>

<a name="dup2"></a>
<hr><h2>dup2</h2>
<a name="dup2.Operation"></a>
<p><b>Operation</b><br>
<blockquote><a name="67834"></a>
Duplicate the top one or two operand stack values<p><Table Border="1">
</blockquote>

<p><b>Format</b><br>
<blockquote>

<tr><td><a name="67833"></a>
 <i>dup2</i>
<td><a name="87568"></a>
 

</Table><br></blockquote><p>
<a name="dup2.Forms"></a>
<p><b>Forms</b><br>
<blockquote><a name="67835"></a>
<i>dup2</i> = 92 (0x5c)</blockquote><p>
<a name="dup2.Operand"></a>
<p><b>Operand Stack</b><br>
<blockquote><a name="67836"></a>
Form 1:</blockquote><p>
<blockquote><a name="360424"></a>
..., <i>value2</i>, <i>value1</i> <img src="chars/arrwdbrt.gif"> ..., <i>value2</i>, <i>value1</i><em>, </em><i>value2</i>, <i>value1</i></blockquote><p>
<blockquote><a name="360427"></a>
where both <i>value1</i> and <i>value2</i> are values of a category 1 computational type <a href="Overview.doc.html#7565">(&#167;3.11.1)</a>.</blockquote><p>
<blockquote><a name="356577"></a>
Form 2:</blockquote><p>
<a name="dup2."></a>
<blockquote><a name="349726"></a>
..., <i>value</i> <img src="chars/arrwdbrt.gif"> ..., <i>value</i>, <i>value</i></blockquote><p>
<blockquote><a name="360428"></a>
where <i>value</i> is a value of a category 2 computational type <a href="Overview.doc.html#7565">(&#167;3.11.1)</a>.</blockquote><p>
<a name="dup2.Description"></a>
<p><b>Description</b><br>
<blockquote><a name="67837"></a>
Duplicate the top one or two values on the operand stack and push the duplicated value or values back onto the operand stack in the original order. </blockquote><p>

<a name="dup2_x1"></a>
<hr><h2>dup2_x1</h2>
<a name="dup2_x1.Operation"></a>
<p><b>Operation</b><br>
<blockquote><a name="67852"></a>
Duplicate the top one or two operand stack values and insert two or three values down<p><Table Border="1">
</blockquote>

<p><b>Format</b><br>
<blockquote>

<tr><td><a name="67851"></a>
 <i>dup2_x1</i>
<td><a name="87568"></a>
 

</Table><br></blockquote><p>
<a name="dup2_x1.Forms"></a>
<p><b>Forms</b><br>
<blockquote><a name="67853"></a>
<i>dup2_x1</i> = 93 (0x5d)</blockquote><p>
<a name="dup2_x1.Operand"></a>
<p><b>Operand Stack</b><br>
<blockquote><a name="67854"></a>
Form 1:</blockquote><p>
<blockquote><a name="360435"></a>
..., <i>value3</i>, <i>value2</i>, <i>value1</i> <img src="chars/arrwdbrt.gif"> ..., <i>value2</i><em>, </em><i>value1</i>, <i>value3</i>, <i>value2</i>, <i>value1</i></blockquote><p>
<blockquote><a name="360438"></a>
where <i>value1</i>, <i>value2</i>, and <i>value3</i> are all values of a category 1 computational type <a href="Overview.doc.html#7565">(&#167;3.11.1)</a>.</blockquote><p>
<blockquote><a name="349758"></a>
Form 2:</blockquote><p>
<a name="dup2_x1."></a>
<blockquote><a name="349751"></a>
..., <i>value2</i>, <i>value1</i> <img src="chars/arrwdbrt.gif"> ..., <i>value1</i>, <i>value2</i>, <i>value1</i></blockquote><p>
<blockquote><a name="360439"></a>
where <i>value1</i> is a value of a category 2 computational type and <i>value2</i> is a value of a category 1 computational type <a href="Overview.doc.html#7565">(&#167;3.11.1)</a>.</blockquote><p>
<a name="dup2_x1.Description"></a>
<p><b>Description</b><br>
<blockquote><a name="67855"></a>
Duplicate the top one or two values on the operand stack and insert the duplicated values, in the original order, one value beneath the original value or values in the operand stack. </blockquote><p>

<a name="dup2_x2"></a>
<hr><h2>dup2_x2</h2>
<a name="dup2_x2.Operation"></a>
<p><b>Operation</b><br>
<blockquote><a name="360406"></a>
Duplicate the top one or two operand stack values and insert two, three, or four values down<p><Table Border="1">
</blockquote>

<p><b>Format</b><br>
<blockquote>

<tr><td><a name="360403"></a>
 <i>dup2_x2</i>
<td><a name="360405"></a>
 

</Table><br></blockquote><p>
<a name="dup2_x2.Forms"></a>
<p><b>Forms</b><br>
<blockquote><a name="67865"></a>
<i>dup2_x2</i> = 94 (0x5e)</blockquote><p>
<a name="dup2_x2.Operand"></a>
<p><b>Operand Stack</b><br>
<blockquote><a name="67866"></a>
Form 1:</blockquote><p>
<blockquote><a name="360447"></a>
...,<em> </em><i>value4</i>, <i>value3</i>, <i>value2</i>, <i>value1</i> <img src="chars/arrwdbrt.gif"> ...<em>, </em><i>value2</i>, <i>value1</i>, <i>value4</i>, <i>value3</i>, <i>value2</i>, <i>value1</i></blockquote><p>
<blockquote><a name="364327"></a>
where <i>value1</i>, <i>value2</i>, <i>value3</i>, and <i>value4</i> are all values of a category 1 computational type <a href="Overview.doc.html#7565">(&#167;3.11.1)</a>.</blockquote><p>
<blockquote><a name="349801"></a>
Form 2:</blockquote><p>
<a name="dup2_x2."></a>
<blockquote><a name="349796"></a>
...,<em> </em><i>value3</i>, <i>value2</i>, <i>value1</i> <img src="chars/arrwdbrt.gif"> ...<em>, </em><i>value1</i>, <i>value3</i>, <i>value2</i>, <i>value1</i></blockquote><p>
<blockquote><a name="364869"></a>
where <i>value1</i> is a value of a category 2 computational type and <i>value2</i> and <i>value3</i> are both values of a category 1 computational type <a href="Overview.doc.html#7565">(&#167;3.11.1)</a>.</blockquote><p>
<blockquote><a name="349803"></a>
Form 3:</blockquote><p>
<a name="dup2_x2."></a>
<blockquote><a name="349805"></a>
...,<em> </em><i>value3</i>, <i>value2</i>, <i>value1</i> <img src="chars/arrwdbrt.gif"> ...<em>, </em><i>value2</i>, <i>value1</i>, <i>value3</i>, <i>value2</i>, <i>value1</i></blockquote><p>
<blockquote><a name="364877"></a>
where <i>value1</i> and <i>value2</i> are both values of a category 1 computational type and <i>value3</i> is a value of a category 2 computational type <a href="Overview.doc.html#7565">(&#167;3.11.1)</a>.</blockquote><p>
<blockquote><a name="360452"></a>
Form 4:</blockquote><p>
<a name="dup2_x2."></a>
<blockquote><a name="349813"></a>
...,<em> </em><i>value2</i>, <i>value1</i> <img src="chars/arrwdbrt.gif"> ...<em>, </em><i>value1</i>, <i>value2</i>, <i>value1</i></blockquote><p>
<blockquote><a name="488961"></a>
where <i>value1</i> and <i>value2</i> are both values of a category 2 computational type <a href="Overview.doc.html#7565">(&#167;3.11.1)</a>.</blockquote><p>

<a name="dup2_x2.Description"></a>
<p><b>Description</b><br>
<blockquote><a name="67867"></a>
Duplicate the top one or two values on the operand stack and insert the duplicated values, in the original order, into the operand stack.</blockquote><p>


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<font size="-1"><i>The Java</i><sup><font size=-2>TM</font></sup><i> Virtual Machine Specification </i><br>
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