<!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>59..5f 22c</td> <td>i<i>instanceop</i> vA, vB, field@CCCC<br/> 59: iput<br/> 5a: iput-wide<br/> 5b: iput-object<br/> 5c: iput-boolean<br/> 5d: iput-byte<br/> 5e: iput-char<br/> 5f: iput-short </td> <td><code>A:</code> source 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 stack frame. </li> <li> For the -wide variant, also A+1 must be a valid register index in the current stack frame. </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> <li> For the -object variant, the instance referenced by register vA must be assignment-compatible to the type of the field. </li> </ul> <h2>Behavior</h2> <ul> <li> For all but the -wide variant, the value of register vA is move into the field, that is, <object>.<field>'=vA. </li> <li> For the -wide variant, the registers vA and v(A+1) are moved into the field as follows: <ul> <li> <object>.<field>' = vA << 0x20 | v(A+1) </li> </ul> </li> </ul> <h2>Exceptions</h2> <ul> <li> NullPointerException if vB=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, or final. </li> </ul> </body> </html>