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>sget<kind></title> 7<link rel=stylesheet href="opcode.css"> 8</head> 9 10<body> 11 12<h1>sget<kind></h1> 13 14<h2>Purpose</h2> 15 16<p> 17Perform the identified object static field operation with the identified static 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>60..6d 21c</td> 38 <td>s<i>staticop</i> vAA, field@BBBB<br/> 39 60: sget<br/> 40 61: sget-wide<br/> 41 62: sget-object<br/> 42 63: sget-boolean<br/> 43 64: sget-byte<br/> 44 65: sget-char<br/> 45 66: sget-short<br/> 46 </td> 47 <td><code>A:</code> dest value register or pair; (8 bits)<br/> 48 <code>B:</code> static field reference index (16 bits)</td> 49</tr> 50</tbody> 51</table> 52 53<h2>Constraints</h2> 54 55<ul> 56 <li> 57 A must be a valid register index in the current stackframe. 58 </li> 59 <li> 60 For the -wide variant, also A+1 must be a valid register index in the 61 current stackframe. 62 </li> 63 <li> 64 B must be a valid index into the field reference pool. 65 </li> 66 <li> 67 The field denoted by B must be static. The type of the field denoted by B 68 must match the variant of the instruction. 69 </li> 70</ul> 71 72<h2>Behavior</h2> 73 74<ul> 75 <li> 76 The value of the given instance field is read from the given object and 77 moved into the given register vA, that is, vA'=<class>.<field>. 78 </li> 79 <li> 80 If v(A-1) is the lower half of a register pair, v(A-1)' becomes undefined. 81 </li> 82 <li> 83 For all but the -wide variant, if v(A+1) is the upper half of a register 84 pair, v(A+1)' becomes undefined. 85 </li> 86 <li> 87 For the -wide variant, if v(A+2) is the upper half of a register pair, 88 v(A+2)' becomes undefined. 89 </li> 90</ul> 91 92<h2>Exceptions</h2> 93 94<ul> 95 <li> 96 NullPointerException if object is null. 97 </li> 98 <li> 99 IllegalAccessException if <object>.<field> is not visible from 100 the current context according to the usual visibility and access rules of 101 the Java programming language. 102 </li> 103</ul> 104 105</body> 106</html> 107