diff options
Diffstat (limited to 'docs/opcodes/opcode-52-iget.html')
| -rw-r--r-- | docs/opcodes/opcode-52-iget.html | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/docs/opcodes/opcode-52-iget.html b/docs/opcodes/opcode-52-iget.html new file mode 100644 index 0000000..837b511 --- /dev/null +++ b/docs/opcodes/opcode-52-iget.html @@ -0,0 +1,109 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> + +<html> + +<head> +<title>iget<kind></title> +<link rel=stylesheet href="opcode.css"> +</head> + +<body> + +<h1>iget<kind></h1> + +<h2>Purpose</h2> + +<p> +Perform the identified object instance field operation with the identified +field, loading or storing into the value register. +</p> +<p> +Note: These opcodes are reasonable candidates for static linking, altering the +field argument to be a more direct offset. +</p> + +<h2>Details</h2> + +<table class="instruc"> +<thead> +<tr> + <th>Op & Format</th> + <th>Mnemonic / Syntax</th> + <th>Arguments</th> +</tr> +</thead> +<tbody> +<tr> + <td>52..58 22c</td> + <td>i<i>instanceop</i> vA, vB, field@CCCC<br/> + 52: iget<br/> + 53: iget-wide<br/> + 54: iget-object<br/> + 55: iget-boolean<br/> + 56: iget-byte<br/> + 57: iget-char<br/> + 58: iget-short<br/> + </td> + <td><code>A:</code> dest value register or pair; (4 bits)<br/> + <code>B:</code> object register (4 bits)<br/> + <code>C:</code> instance field reference index (16 bits)</td> +</tr> +</tbody> +</table> + +<h2>Constraints</h2> + +<ul> + <li> + A and B must be valid register indices in the current stackframe. + </li> + <li> + For the -wide variant, also A+1 must be a valid register index in the + current stackframe. + </li> + <li> + Register vB must contain an object reference. + </li> + <li> + C must be a valid index into the field reference pool. + </li> + <li> + The field must be an instance field. The type of the field denoted by C must + match the variant of the instruction. + </li> +</ul> + +<h2>Behavior</h2> + +<ul> + <li> + The value of the given instance field is read from the given object and + moved into the given register vA, that is, vA'=<object>.<field>. + </li> + <li> + If v(A-1) is the lower half of a register pair, v(A-1)' becomes undefined. + </li> + <li>For all but the -wide variant, if v(A+1) is the upper half of a register + pair, v(A+1)' becomes undefined. + </li> + <li> + For the -wide variant, if v(A+2) is the upper half of a register pair, + v(A+2)' becomes undefined. + </li> +</ul> + +<h2>Exceptions</h2> + +<ul> + <li> + NullPointerException if object is null. + </li> + <li> + IllegalAccessException if <object>.<field> is not visible from + the current context according to the usual visibility and access rules of + the Java programming language. + </li> +</ul> + +</body> +</html> |