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Consider the following Java code.
This is probably translated into byte code like (assuming the above was put in a method):
| Mnemonic | Opcode
(in hex) | Description |
| A |
| aaload | 32 | loads onto the stack a reference to an array |
| aastore | 53 | stores into a reference to an array |
| aconst_null | 01 | pushes a null reference onto the stack |
| aload | 19 | loads a reference onto the stack from a local variable |
| aload_0 | 2a | loads a reference onto the stack from local variable 0 |
| aload_1 | 2b | loads a reference onto the stack from local variable 1 |
| aload_2 | 2c | loads a reference onto the stack from local variable 2 |
| aload_3 | 2d | loads a reference onto the stack from local variable 3 |
| anewarray | bd | creates a new array of references |
| areturn | b0 | returns a reference from a method |
| arraylength | be | gets the length of an array |
| astore | 3a | stores a reference into a local variable |
| astore_0 | 4b | stores a reference into local variable 0 |
| astore_1 | 4c | stores a reference into local variable 1 |
| astore_2 | 4d | stores a reference into local variable 2 |
| astore_3 | 4e | stores a reference into local variable 3 |
| athrow | bf | throws an error or exception |
| B |
| baload | 33 | loads a byte or Boolean value from an array |
| bastore | 54 | stores a byte or Boolean value into an array |
| bipush | 10 | pushes a byte onto the stack |
| C |
| caload | 34 | loads a char from an array |
| castore | 55 | stores a char into an array |
| checkcast | c0 | checks whether an object is of a certain type |
| D |
| d2f | 90 | converts a double to a float |
| d2i | 8e | converts a double to an int |
| d2l | 8f | converts a double to a long |
| dadd | 63 | adds two doubles |
| daload | 31 | loads a double from an array |
| dastore | 52 | stores a double into an array |
| dcmpg | 98 | compares two doubles |
| dcmpl | 97 | compares two doubles |
| dconst_0 | 0e | pushes the constant 0.0 onto the stack |
| dconst_1 | 0f | pushes the constant 1.0 onto the stack |
| ddiv | 6f | divides two doubles |
| dload | 18 | loads a double from a local variable |
| dload_0 | 26 | loads a double from local variable 0 |
| dload_1 | 27 | loads a double from local variable 1 |
| dload_2 | 28 | loads a double from local variable 2 |
| dload_3 | 29 | loads a double from local variable 3 |
| dmul | 6b | multiplies two doubles |
| dneg | 77 | negates a double |
| drem | 73 | gets the remainder from a division between two doubles |
| dreturn | af | returns a double from a method |
| dstore | 39 | stores a double into a local variable |
| dstore_0 | 47 | stores a double into local variable 0 |
| dstore_1 | 48 | stores a double into local variable 1 |
| dstore_2 | 49 | stores a double into local variable 2 |
| dstore_3 | 4a | stores a double into local variable 3 |
| dsub | 67 | subtracts a double from another |
| dup | 59 | duplicates the value on top of the stack |
| dup_x1 | 5a | inserts a copy of the top value into the stack two values from the top |
| dup_x2 | 5b | inserts a copy of the top value into the stack two or three values from the top |
| dup2 | 5c | duplicate top two stack words |
| dup2_x1 | 5d | duplicate two words and insert beneath third word |
| dup2_x2 | 5e | duplicate two words and insert beneath fourth word |
| F |
| f2d | 8d | converts a float to a double |
| f2i | 8b | converts a float to an int |
| f2l | 8c | converts a float to a long |
| fadd | 62 | adds two floats |
| faload | 30 | loads a float from an array |
| fastore | 51 | stores a float in an array |
| fcmpg | 96 | compares two floats |
| fcmpl | 95 | compares two floats |
| fconst_0 | 0b | pushes 0.0f on the stack |
| fconst_1 | 0c | pushes 1.0f on the stack |
| fconst_2 | 0d | pushes 2.0f on the stack |
| fdiv | 6e | divides two floats |
| fload | 17 | loads a float from a local value |
| fload_0 | 22 | loads a float from local variable 0 |
| fload_1 | 23 | loads a float from local variable 1 |
| fload_2 | 24 | loads a float from local variable 2 |
| fload_3 | 25 | loads a float from local variable 3 |
| fmul | 6a | multiplies two floats |
| fneg | 76 | negates a float |
| frem | 72 | gets the remainder from a division between two floats |
| freturn | ae | returns a float |
| fstore | 38 | stores a float into a local variable |
| fstore_0 | 43 | stores a float into local variable 0 |
| fstore_1 | 44 | stores a float into local variable 1 |
| fstore_2 | 45 | stores a float into local variable 2 |
| fstore_3 | 46 | stores a float into local variable 3 |
| fsub | 66 | subtracts two floats |
| G |
| getfield | b4 | gets a field of an object |
| getstatic | b2 | gets a static field of a class |
| goto | a7 | goes to another instruction |
| goto_w | c8 | goes to another instruction |
| I |
| i2b | 91 | converts an int into a byte |
| i2c | 92 | converts an int into a character |
| i2d | 87 | converts an int into a double |
| i2f | 86 | converts an int into a float |
| i2l | 85 | converts an int into a long |
| i2s | 93 | converts an int into a short |
| iadd | 60 | adds two ints together |
| iaload | 2e | loads an int from an array |
| iand | 7e | performs a logical and on two integers |
| iastore | 4f | stores an int into an array |
| iconst_m1 | 02 | loads the int value -1 onto the stack |
| iconst_0 | 03 | loads the int value 0 onto the stack |
| iconst_1 | 04 | loads the int value 1 onto the stack |
| iconst_2 | 05 | loads the int value 2 onto the stack |
| iconst_3 | 06 | loads the int value 3 onto the stack |
| iconst_4 | 07 | loads the int value 4 onto the stack |
| iconst_5 | 08 | loads the int value 5 onto the stack |
| idiv | 6c | divides two integers |
| if_acmpeq | a5 | branch if reference comparison succeeds |
| if_acmpne | a6 | branch if int comparison succeeds |
| if_icmpeq | 9f | branch if int is value of comparator |
| if_icmpne | a0 | branch if int is not value of comparator |
| if_icmplt | a1 | branch if int is less than value of comparator |
| if_icmpge | a2 | branch if int is greater than or equal to value of comparator |
| if_icmpgt | a3 | branch if int is greater than value of comparator |
| if_icmple | a4 | branch if int is less than or equal to value of comparator |
| ifeq | 99 | branch if int is 0 |
| ifne | 9a | branch if int is not 0 |
| iflt | 9b | branch if int is less than 0 |
| ifge | 9c | branch if int is greater than or equal to 0 |
| ifgt | 9d | branch if int is greater than 0 |
| ifle | 9e | branch if int is less than or equal 0 |
| ifnonnull | c7 | branch if reference is not null 0 |
| ifnull | c6 | branch if reference is null 0 |
| iinc | 84 | increment local variable by constant |
| iload | 15 | loads an int from a variable |
| iload_0 | 1a | loads an int from variable 0 |
| iload_1 | 1b | loads an int from variable 1 |
| iload_2 | 1c | loads an int from variable 2 |
| iload_3 | 1d | loads an int from variable 3 |
| imul | 68 | multiply two integers |
| ineg | 74 | negate int |
| instanceof | c1 | determines if an object is of a given type |
| invokeinterface | b9 | invokes an interface |
| invokespecial | b7 | invoke instance method |
| invokestatic | b8 | invoke a static method |
| invokevirtual | b6 | invoke virtual method |
| ior | 80 | logical int or |
| irem | 70 | logical int remainder |
| ireturn | ac | returns an integer from a method |
| ishl | 78 | int shift left |
| ishr | 7a | int shift right |
| istore | 36 | store int into variable |
| istore_0 | 3b | store int into variable 0 |
| istore_1 | 3c | store int into variable 1 |
| istore_2 | 3d | store int into variable 2 |
| istore_3 | 3e | store int into variable 3 |
| isub | 64 | int subtract |
| iushr | 7c | int shift right |
| ixor | 82 | int xor |
| J |
| jsr | a8 | jump to subroutine |
| jsr_w | c9 | jump to subroutine (wide index) |
| L |
| l2d | 8a | converts a long to a double |
| l2f | 89 | converts a long to a float |
| l2i | 88 | converts a long to a int |
| ladd | 61 | add two longs |
| laload | 2f | |
| land | 7f | bitwise and of two longs |
| lastore | 50 | |
| lcmp | 94 | compares two longs values |
| lconst_0 | 09 | pushes the long 0 onto the stack |
| lconst_1 | 0a | pushes the long 1 onto the stack |
| ldc | 12 | pushes a constant (String, int or float) onto the stack |
| ldc_w | 13 | pushes a constant (String, int or float) onto the stack (wide index) |
| ldc2_w | 14 | |
| ldiv | 6d | divide two longs |
| lload | 16 | |
| lload_0 | 1e | |
| lload_1 | 1f | |
| lload_2 | 20 | |
| lload_3 | 21 | |
| lmul | 69 | multiplies two longs |
| lneg | 75 | negates a long |
| lookupswitch | ab | |
| lor | 81 | bitwise or of two longs |
| lrem | 71 | |
| lreturn | ad | |
| lshl | 69 | |
| lshr | 7b | |
| lstore | 37 | store a long in a local variable |
| lstore_0 | 3f | |
| lstore_1 | 40 | |
| lstore_2 | 41 | |
| lstore_3 | 42 | |
| lsub | 65 | subtract two longs |
| lushr | 7d | |
| lxor | 83 | bitwise exclusive or of two longs |
| M |
| monitorenter | c2 | |
| monitorexit | c3 | |
| multianewarray | c5 | |
| N |
| new | bb | |
| newarray | bc | |
| nop | 00 | performs no operation |
| P |
| pop | 57 | discards the top value on the stack |
| pop2 | 58 | discards the top two values on the stack |
| putfield | b5 | |
| putstatic | b3 | |
| R |
| ret | a9 | |
| return | b1 | |
| S |
| saload | 35 | |
| sastore | 56 | |
| sipush | | pushes a signed integer onto the stack |
| swap | 5f | |
| T |
| tableswitch | aa | |
| W |
| wide | c4 | |
| Unused |
| breakpoint | ca | reserved for breakpoints in Java debuggers; should not appear in any class file |
| impdep1 | fe | reserved for implementation-dependent operations within debuggers; should not appear in any class file |
| impdep2 | ff | reserved for implementation-dependent operations within debuggers; should not appear in any class file |
| (no name) | cb-fd | these values are currently unassigned for opcodes and are reserved for future use |
| xxxunusedxxx | ba | this opcode is reserved "for historical reasons" |
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