| The Android Open Source Project | f6c3871 | 2009-03-03 19:28:47 -0800 | [diff] [blame] | 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>const-class</title> |
| 7 | <link rel=stylesheet href="opcode.css"> |
| 8 | </head> |
| 9 | |
| 10 | <body> |
| 11 | |
| 12 | <h1>const-class</h1> |
| 13 | |
| 14 | <h2>Purpose</h2> |
| 15 | |
| 16 | <p> |
| 17 | Move a reference to the class specified by the given index into the specified |
| 18 | register. In the case where the indicated type is primitive, this will store a |
| 19 | reference to the primitive type's degenerate class. |
| 20 | </p> |
| 21 | |
| 22 | <h2>Details</h2> |
| 23 | |
| 24 | <table class="instruc"> |
| 25 | <thead> |
| 26 | <tr> |
| 27 | <th>Op & Format</th> |
| 28 | <th>Mnemonic / Syntax</th> |
| 29 | <th>Arguments</th> |
| 30 | </tr> |
| 31 | </thead> |
| 32 | <tbody> |
| 33 | <tr> |
| 34 | <td>1c 21c</td> |
| 35 | <td>const-class vAA, type@BBBB</td> |
| 36 | <td><code>A:</code> destination register (8 bits)<br/> |
| 37 | <code>B:</code> type index</td> |
| 38 | </tr> |
| 39 | </tbody> |
| 40 | </table> |
| 41 | |
| 42 | <h2>Constraints</h2> |
| 43 | |
| 44 | <ul> |
| 45 | <li> |
| 46 | A must be a valid register index in the current stack frame. |
| 47 | </li> |
| 48 | <li> |
| 49 | B must be a valid index into the type constant pool. |
| 50 | </li> |
| 51 | </ul> |
| 52 | |
| 53 | <h2>Behavior</h2> |
| 54 | |
| 55 | <ul> |
| 56 | <li> |
| 57 | An attempt is made to get a reference to the class C the name of which is |
| 58 | contained in type pool entry B. |
| 59 | </li> |
| 60 | <li> |
| 61 | If B refers to a primitive type, the corresponding degenerate class is used |
| 62 | instead. |
| 63 | </li> |
| 64 | <li> |
| 65 | If C has not been loaded and resolved before, it is being loaded and |
| 66 | resolved. All exceptions that are possible during class loading can occur at |
| 67 | this point. |
| 68 | </li> |
| 69 | <li> |
| 70 | A reference to C is moved into register vA, that is, vA' = C. |
| 71 | </li> |
| 72 | <li> |
| 73 | If v(A-1) is the lower half of a register pair, v(A-1)' becomes undefined. |
| 74 | </li> |
| 75 | <li> |
| 76 | If v(A+1) is the upper half of a register pair, v(A+1)' becomes undefined. |
| 77 | </li> |
| 78 | </ul> |
| 79 | |
| 80 | <h2>Exceptions</h2> |
| 81 | |
| 82 | <ul> |
| 83 | <li> |
| 84 | ClassNotFoundException is thrown if the class does not exist at all. |
| 85 | </li> |
| 86 | <li> |
| 87 | VerifyError is thrown if the class does exist, but could not be verified. |
| 88 | </li> |
| 89 | </ul> |
| 90 | |
| 91 | </body> |
| 92 | </html> |