1<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 2 3<html> 4 5<head> 6<title>iget<kind></title> 7<link rel=stylesheet href="opcode.css"> 8</head> 9 10<body> 11 12<h1>iget<kind></h1> 13 14<h2>Purpose</h2> 15 16<p> 17Perform the identified object instance field operation with the identified 18field, loading or storing into the value register. 19</p> 20<p> 21Note: These opcodes are reasonable candidates for static linking, altering the 22field argument to be a more direct offset. 23</p> 24 25<h2>Details</h2> 26 27<table class="instruc"> 28<thead> 29<tr> 30 <th>Op & Format</th> 31 <th>Mnemonic / Syntax</th> 32 <th>Arguments</th> 33</tr> 34</thead> 35<tbody> 36<tr> 37 <td>59..5f 22c</td> 38 <td>i<i>instanceop</i> vA, vB, field@CCCC<br/> 39 59: iput<br/> 40 5a: iput-wide<br/> 41 5b: iput-object<br/> 42 5c: iput-boolean<br/> 43 5d: iput-byte<br/> 44 5e: iput-char<br/> 45 5f: iput-short 46 </td> 47 <td><code>A:</code> source value register or pair; (4 bits)<br/> 48 <code>B:</code> object register (4 bits)<br/> 49 <code>C:</code> instance field reference index (16 bits)</td> 50</tr> 51</tbody> 52</table> 53 54<h2>Constraints</h2> 55 56<ul> 57 <li> 58 A and B must be valid register indices in the current stack frame. 59 </li> 60 <li> 61 For the -wide variant, also A+1 must be a valid register index in the 62 current stack frame. 63 </li> 64 <li> 65 Register vB must contain an object reference. 66 </li> 67 <li> 68 C must be a valid index into the field reference pool. 69 </li> 70 <li> 71 The field must be an instance field. The type of the field denoted by C must 72 match the variant of the instruction. 73 </li> 74 <li> 75 For the -object variant, the instance referenced by register vA must be 76 assignment-compatible to the type of the field. 77 </li> 78</ul> 79 80<h2>Behavior</h2> 81 82<ul> 83 <li> 84 For all but the -wide variant, the value of register vA is move into the 85 field, that is, <object>.<field>'=vA. 86 </li> 87 <li> 88 For the -wide variant, the registers vA and v(A+1) are moved into the 89 field as follows: 90 <ul> 91 <li> 92 <object>.<field>' = vA << 0x20 | v(A+1) 93 </li> 94 </ul> 95 </li> 96</ul> 97 98<h2>Exceptions</h2> 99 100<ul> 101 <li> 102 NullPointerException if vB=null. 103 </li> 104 <li> 105 IllegalAccessException if <object>.<field> is not visible from 106 the current context according to the usual visibility and access rules of 107 the Java programming language, or final. 108 </li> 109</ul> 110 111</body> 112</html> 113