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      5 <head>
      6 <title>move-wide</title>
      7 <link rel=stylesheet href="opcode.css">
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     10 <body>
     11 
     12 <h1>move-wide</h1>
     13 
     14 <h2>Purpose</h2>
     15 
     16 <p>
     17 Move the contents of one register-pair to another.
     18 </p>
     19 <p>
     20 Note: It is legal to move from vN to either vN-1 or vN+1, so implementations
     21 must arrange for both halves of a register pair to be read before anything is
     22 written.
     23 </p>
     24 
     25 <h2>Details</h2>
     26 
     27 <table class="instruc">
     28 <thead>
     29 <tr>
     30   <th>Op &amp; Format</th>
     31   <th>Mnemonic / Syntax</th>
     32   <th>Arguments</th>
     33 </tr>
     34 </thead>
     35 <tbody>
     36 <tr>
     37   <td>04 12x</td>
     38   <td>move-wide vA, vB</td>
     39   <td><code>A:</code> destination register pair (4 bits)<br/>
     40     <code>B:</code> source register pair (4 bits)</td>
     41 </tr>
     42 <tr>
     43   <td>05 22x</td>
     44   <td>move-wide/from16 vAA, vBBBB</td>
     45   <td><code>A:</code> destination register pair (8 bits)<br/>
     46     <code>B:</code> source register pair (16 bits)</td>
     47 </tr>
     48 <tr>
     49   <td>06 32x</td>
     50   <td>move-wide/16 vAAAA, vBBBB</td>
     51   <td><code>A:</code> destination register pair (16 bits)<br/>
     52     <code>B:</code> source register pair (16 bits)</td>
     53 </tr>
     54 </tbody>
     55 </table>
     56 
     57 <h2>Constraints</h2>
     58 
     59 <ul>
     60   <li>
     61     Both A+1 and B+1 must be valid register indices in the current stackframe
     62     (which includes A and B being valid).
     63   </li>
     64   <li>
     65     Register vB must be the lower half of a register pair (which excludes the
     66     case of it containing a reference).
     67   </li>
     68   <li>
     69     Both register vB and v(B+1) must be defined.
     70   </li>
     71 </ul>
     72 
     73 <h2>Behavior</h2>
     74 
     75 <ul>
     76   <li>
     77     The value of register vB is moved to register vA, that is, vA' = vB.
     78   </li>
     79   <li>
     80     The value of register v(B+1) is moved to register v(A+1), that is, v(A+1)'
     81     = v(B+1).
     82   </li>
     83   <li>
     84     If register v(A-1) is the lower half of a register pair, then v(A-1)'
     85     becomes undefined.
     86   </li>
     87   <li>
     88     If register v(A+2) is the upper half of a register pair, then v(A+2)'
     89     becomes undefined.
     90   </li>
     91   <li>
     92     If A = B-1, then v(B+1)' becomes undefined.
     93   </li>
     94   <li>
     95     If A = B+1, then v(B)' becomes undefined.
     96   </li>
     97 </ul>
     98 
     99 <h2>Exceptions</h2>
    100 
    101 <p>
    102 None.
    103 </p>
    104 
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