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Bytecode instruction shorthand
Table of bytecode instructions
| The bytecode | mnemonics | Instruction meaning |
|---|---|---|
| 0x00 | nop | No eggs with |
| 0x01 | aconst_null | Push NULL to the top of the stack |
| 0x02 | iconst_m1 | Push int -1 to the top of the stack |
| 0x03 | iconst_0 | Push int 0 to the top of the stack |
| 0x04 | iconst_1 | Push int 1 to the top of the stack |
| 0x05 | iconst_2 | Push int 2 to the top of the stack |
| 0x06 | iconst_3 | Push int 3 to the top of the stack |
| 0x07 | iconst_4 | Push int 4 to the top of the stack |
| 0x08 | iconst_5 | Push int 5 to the top of the stack |
| 0x09 | lconst_0 | Push long 0 to the top of the stack |
| 0x0a | lconst_1 | Push long 1 to the top of the stack |
| 0x0b | fconst_0 | Push type float 0 to the top of the stack |
| 0x0c | fconst_1 | Push type float 1 to the top of the stack |
| 0x0d | fconst_2 | Push type float 2 to the top of the stack |
| 0x0e | dconst_0 | Push double 0 to the top of the stack |
| 0x0f | dconst_1 | Push double 1 to the top of the stack |
| 0x10 | bipush | Push constant values of a single byte (-128~127) to the top of the stack |
| 0x11 | sipush | Push a short integer constant value (-32768~32767) to the top of the stack |
| 0x12 | ldc | Push int, float, or String constant values from the constant pool to the top of the stack |
| 0x13 | ldc_w | Push int, float, or String constant values from the constant pool to the top of the stack (wide index) |
| 0x14 | ldc2_w | Push a long or double constant value from the constant pool to the top of the stack (wide index) |
| 0x15 | iload | Pushes the specified local variable of type int to the top of the stack |
| 0x16 | lload | Pushes the specified long local variable to the top of the stack |
| 0x17 | fload | Pushes the specified local variable of type float to the top of the stack |
| 0x18 | dload | Pushes the specified double local variable to the top of the stack |
| 0x19 | aload | Pushes the specified reference type local variable to the top of the stack |
| 0x1a | iload_0 | Push the first local variable of int to the top of the stack |
| 0x1b | iload_1 | Push the second local variable of int to the top of the stack |
| 0x1c | iload_2 | Push the third local variable of type int to the top of the stack |
| 0x1d | iload_3 | Push the fourth local variable of int to the top of the stack |
| 0x1e | lload_0 | Push the first long local variable to the top of the stack |
| 0x1f | lload_1 | Push the second long local variable to the top of the stack |
| 0x20 | lload_2 | Push the third long local variable to the top of the stack |
| 0x21 | lload_3 | Push the fourth long local variable to the top of the stack |
| 0x22 | fload_0 | Push the first local variable of type float to the top of the stack |
| 0x23 | fload_1 | Push the second local variable of type float to the top of the stack |
| 0x24 | fload_2 | Push the third local variable of type float to the top of the stack |
| 0x25 | fload_3 | Push the fourth local variable of type float to the top of the stack |
| 0x26 | dload_0 | Push the first double local variable to the top of the stack |
| 0x27 | dload_1 | Push the second double local variable to the top of the stack |
| 0x28 | dload_2 | Push the third double local variable to the top of the stack |
| 0x29 | dload_3 | Push the fourth local variable of type double to the top of the stack |
| 0x2a | aload_0 | Push the first reference type local variable to the top of the stack |
| 0x2b | aload_1 | Push the first reference type local variable to the top of the stack |
| 0x2c | aload_2 | Push the first reference type local variable to the top of the stack |
| 0x2d | aload_3 | Push the first reference type local variable to the top of the stack |
| 0x2e | iaload | Pushes the value of the specified index of an int to the top of the stack |
| 0x2f | laload | Pushes the value of the specified index of the long array to the top of the stack |
| 0x30 | faload | Pushes the value of the specified index of a float array to the top of the stack |
| 0x31 | daload | Pushes the value of the specified index of an array double to the top of the stack |
| 0x32 | aaload | Pushes the value of the specified index of the array of reference types to the top of the stack |
| 0x33 | baload | Pushes the value of the Boolean /byte array specified index to the top of the stack |
| 0x34 | caload | Pushes the value of a char array to the top of the stack |
| 0x35 | saload | Pushes the value of the specified index of the short array to the top of the stack |
| 0x36 | istore | Stores the top int value to the specified local variable |
| 0x37 | lstore | Stores the top of the stack long value to the specified local variable |
| 0x38 | fstore | Stores the top stack float value to the specified local variable |
| 0x39 | dstore | Stores the top double to the specified local variable |
| 0x3a | astore | Stores the top of the stack reference value to the specified local variable |
| 0x3b | istore_0 | Store the top int value to the first local variable |
| 0x3c | istore_1 | Store the top int value to the second local variable |
| 0x3d | istore_2 | Store the top int value into the third local variable |
| 0x3e | istore_3 | Store the top int value into the fourth local variable |
| 0x3f | lstore_0 | Store the top of the stack value into the first local variable |
| 0x40 | lstore_1 | Store the top of the stack long value into the second local variable |
| 0x41 | lstore_2 | Store the top of the stack long value into the third local variable |
| 0x42 | lstore_3 | Store the top of the stack long value into the fourth local variable |
| 0x43 | fstore_0 | Store the top stack float value to the first local variable |
| 0x44 | fstore_1 | Store the top stack float value into the second local variable |
| 0x45 | fstore_2 | Store the top stack float value into the third local variable |
| 0x46 | fstore_3 | Store the top stack float value into the fourth local variable |
| 0x47 | dstore_0 | Store the top of the stack double to the first local variable |
| 0x48 | dstore_1 | Store the top of the stack double to the second local variable |
| 0x49 | dstore_2 | Store the top of the stack double into the third local variable |
| 0x4a | dstore_3 | Store the top of the stack double into the fourth local variable |
| 0x4b | astore_0 | Store the top of the stack reference type value into the first local variable |
| 0x4c | astore_1 | Store the top of the stack reference type value into the second local variable |
| 0x4d | astore_2 | Store the top of the stack reference type value into a third local variable |
| 0x4e | astore_3 | Store the top of the stack reference type value into a fourth local variable |
| 0x4f | iastore | Stores the top int into the specified index position of the specified array |
| 0x50 | lastore | Stores the top long value to the specified index position in the specified array |
| 0x51 | fastore | Stores the top float value to the specified index position of the specified array |
| 0x52 | dastore | Stores the top double to the specified index position in the specified array |
| 0x53 | aastore | Stores the top of the stack reference value to the specified index position of the specified array |
| 0x54 | bastore | Stores the top stack Boolean or Byte value to the specified index position of the specified array |
| 0x55 | castore | Stores the top char value to the specified index position in the specified array |
| 0x56 | sastore | Stores the top short value to the specified index position in the specified array |
| 0x57 | pop | Pop top value (value cannot be long or double) |
| 0x58 | pop2 | Pop one (long/double) or two (non-long, non-double) values at the top of the stack |
| 0x59 | dup | Copies the top value of the stack and pushes it to the top |
| 0x5a | dup_x1 | Copies the top value of the stack and pushes the two replicated values to the top |
| 0x5b | dup_x2 | Copy the top value and push three (or two) copy values to the top of the stack |
| 0x5c | dup2 | Copy one (long/double) or two (non-long, non-double) values to the top of the stack and push the copied values to the top |
| 0x5d | dup2_x1 | Double version of the dup_x1 instruction |
| 0x5e | dup2_x2 | Double version of the dup_x2 instruction |
| 0x5f | swap | Swap the two values at the top of the stack (values cannot be long or double) |
| 0x60 | iadd | Add the two int values at the top of the stack and push the result onto the stack |
| 0x61 | ladd | Add the two longs at the top of the stack and push the result onto the stack |
| 0x62 | fadd | Add the two float values at the top of the stack and push the result onto the stack |
| 0x63 | dadd | Add the two double values at the top of the stack and push the result onto the stack |
| 0x64 | isub | Subtract the top two ints and push the result onto the stack |
| 0x65 | lsub | Subtract the top two longs and push the result onto the stack |
| 0x66 | fsub | Subtract the top two float values and push the result onto the stack |
| 0x67 | dsub | Subtract the top two double values and push the result onto the stack |
| 0x68 | imul | Multiply the top two int values and push the result onto the stack |
| 0x69 | lmul | Multiply the top two longs and push the result onto the stack |
| 0x6a | fmul | Multiply the top two float values and push the result to the top of the stack |
| 0x6b | dmul | Multiply the top two double values and push the result to the top of the stack |
| 0x6c | idiv | Divide the top two int values and push the result to the top of the stack |
| 0x6d | ldiv | Divide the top two longs and push the result to the top of the stack |
| 0x6e | fdiv | Divide two float values at the top of the stack and push the result to the top |
| 0x6f | ddiv | Divide the top two double values and push the result to the top of the stack |
| 0x70 | irem | The two int values at the top of the stack are modelled and the result is pushed to the top of the stack |
| 0x71 | lrem | The two long values at the top of the stack are modelled and the result is pushed to the top of the stack |
| 0x72 | frem | Modulo the top two float values and push the result to the top of the stack |
| 0x73 | drem | Modulo the top two double values and push the result to the top of the stack |
| 0x74 | ineg | Take the top int value negative and push the result to the top of the stack |
| 0x75 | lneg | Take the top long value negative and push the result to the top of the stack |
| 0x76 | fneg | Take the top float value negative and push the result to the top of the stack |
| 0x77 | dneg | Take the top double negative and push the result to the top of the stack |
| 0x78 | ishl | Moves the value of int by the specified number of digits to the left and pushes the result to the top of the stack |
| 0x79 | lshl | Moves the long value by the specified number of digits to the left and pushes the result to the top of the stack |
| 0x7a | ishr | Moves the value of int by the specified number of digits to the right and pushes the result to the top of the stack |
| 0x7b | lshr | Moves the long value by the specified number of digits to the right and pushes the result to the top of the stack |
| 0x7c | iushr | Moves an int unsigned to the right by the specified number of digits and pushes the result to the top of the stack |
| 0x7d | lushr | Moves the long value unsigned to the right by the specified number of digits and pushes the result to the top of the stack |
| 0x7e | iand | Position the top two int values and push the result to the top of the stack |
| 0x7f | land | Bitwise sum the top two longs and push the result to the top of the stack |
| 0x80 | ior | Pushes the top two int values bitwise or together |
| 0x81 | lor | The top two longs are bitwise or pushed to the top of the stack |
| 0x82 | ixor | Increments the top two ints bitwise and pushes the result to the top of the stack |
| 0x83 | lxor | The top two longs are bitwise xor and pushed to the top of the stack |
| 0x84 | iinc | Increments a variable of type int to the specified value (I ++, I –, I +=2, etc.) |
| 0x85 | i2l | Cast top int to long and push the result to the top of the stack |
| 0x86 | i2f | Cast the top int value to a float value and push the result to the top of the stack |
| 0x87 | i2d | Cast the top int to a double and push the result to the top of the stack |
| 0x88 | l2i | Cast the top long value to an int value and push the result to the top of the stack |
| 0x89 | l2f | Cast the top long value to a float value and push the result to the top of the stack |
| 0x8a | l2d | Cast the top long to a double and push the result to the top of the stack |
| 0x8b | f2i | Cast a top float value to an int value and push the result to the top of the stack |
| 0x8c | f2l | Cast a top float value to a long value and push the result to the top of the stack |
| 0x8d | f2d | Cast a top float value to a double and push the result to the top of the stack |
| 0x8e | d2i | Cast a double to an int and push the result to the top of the stack |
| 0x8f | d2l | Casts a top double to a long and pushes the result to the top of the stack |
| 0x90 | d2f | Casts a top double value to a float value and pushes the result to the top of the stack |
| 0x91 | i2b | Casts a top-of-stack int value to a byte value and pushes the result to the top of the stack |
| 0x92 | i2c | Cast top int to char and push the result to the top of the stack |
| 0x93 | i2s | Cast top int to short and push the result to the top of the stack |
| 0x94 | lcmp | Compare the top two longs and push the result (1, 0, or -1) to the top of the stack |
| 0x95 | fcmpl | Compare two float values at the top of the stack and push the result (1, 0, or -1) to the top of the stack, or -1 when one of them is a NaN |
| 0x96 | fcmpg | Compare two float values at the top of the stack and push the result (1, 0, or -1) to the top of the stack, or 1 when one of them is a NaN |
| 0x97 | dcmpl | Compare two double values at the top of the stack and push the result (1, 0, or -1) to the top of the stack, or -1 when one of them is a NaN |
| 0x98 | dcmpg | Compare two double values at the top of the stack and push the result (1, 0, or -1) to the top of the stack, and when one of them is NaN, push 1 to the top |
| 0x99 | ifeq | Jump if the top value of int equals 0 |
| 0x9a | ifne | Jump if the top value of int does not equal 0 |
| 0x9b | iflt | Jump if the top value of int is less than 0 |
| 0x9c | ifge | Jump if the top value of int is greater than or equal to 0 |
| 0x9d | ifgt | Jump if the top value of int is greater than 0 |
| 0x9e | ifle | Jump if the top value of int is less than or equal to 0 |
| 0x9f | if_icmpeq | Compares two ints at the top of the stack, jumps when the result equals 0 |
| 0xa0 | if_icmpne | Compares two ints at the top of the stack, jumps if the result is not equal to 0 |
| 0xa1 | if_icmplt | Compare two ints at the top of the stack, jump if the result is less than 0 |
| 0xa2 | if_icmpge | Compares two int values at the top of the stack, jumps if the result is greater than or equal to 0 |
| 0xa3 | if_icmpgt | Compares two ints at the top of the stack, jumps if the result is greater than 0 |
| 0xa4 | if_icmple | Compare two ints at the top of the stack, jump if the result is less than or equal to 0 |
| 0xa5 | if_acmpeg | Compares two referential values at the top of the stack, jumps when the result equals 0 |
| 0xa6 | if_acmpne | Compares two referential values at the top of the stack, jumps if the result is not equal to 0 |
| 0xa7 | goto | Unconditional jump |
| 0xa8 | jsr | Jumps to the specified 16-bit offset and pushes the address of the next JSR instruction to the top of the stack |
| 0xa9 | ret | Returns the index instruction location specified by the local variable (usually used in conjunction with the JSR or jSR_w directive) |
| 0xaa | tableswitch | For switch conditional jump, case value continuous (variable length instruction) |
| 0xab | lookupswitch | For switch conditional jump, case value discontinuous (variable length instruction) |
| 0xac | ireturn | Returns an int from the current method |
| 0xad | lreturn | Returns long from the current method |
| 0xae | freturn | Returns float from the current method |
| 0xaf | dreturn | Returns double from the current method |
| 0xb0 | areturn | Returns object reference 1 from the current method |
| 0xb1 | return | Returns vold from the current method |
| 0xb2 | getstatic | Gets the static field of the specified class and pushes it to the top of the stack |
| 0xb3 | putstatic | Assigns a value to the static field of the specified class |
| 0xb4 | getfield | Gets the instance domain of the specified class and pushes it to the top of the stack |
| 0xb5 | putfield | Assigns a value to the instance field of the specified class |
| 0xb6 | invokevirtual | Calling instance methods |
| 0xb7 | invokespecial | Call superclass constructor, instance initializer, private method |
| 0xb8 | invokestatic | Calling static methods |
| 0xb9 | invokeinterface | Calling interface methods |
| 0xba | invokedynamic | Calling dynamic methods |
| 0xbb | new | Creates an object and pushes its reference to the top of the stack |
| 0xbc | newarray | Creates an array of the specified primitive type and pushes its reference value to the top of the stack |
| 0xbd | anewarray | Creates a reference array and pushes its reference values to the top of the stack |
| 0xbe | arraylength | Get the length of the array and push it to the top of the stack |
| 0xbf | athrow | Throws the top of the stack exception |
| 0xc0 | checkcast | Check for type conversions, failing which throws a ClassCastException |
| 0xc1 | instanceof | Checks if the object is the strength of the specified class, pushing 1 to the top of the stack if so, and 0 otherwise |
| 0xc2 | monitorenter | Get the lock of the object |
| 0xc3 | monitorexit | Release the lock of an object |
| 0xc4 | wide | Expand the width of a local variable |
| 0xc5 | multianewarray | Creates a multidimensional array of the specified type and the specified dimension (the operation stack must contain the length values for each dimension) and pushes its reference values to the top of the stack |
| 0xc6 | ifnull | If the value is null, it jumps |
| 0xc7 | ifnonnull | The value is not null |
| 0xc8 | goto_w | Unconditional jump (wide index) |
| 0xc9 | jsr_w | Jumps to the specified 32-bit offset position and pushes the next instruction address of jSR_W to the top of the stack |
The above instructions can be divided into the following categories for easy memorization:
Loading instructions
- Load class instruction: loads variables from the local variator table onto the operand stack
Others include const, push, and LDC, which can be found in the table.
Storage instructions
- Store class instruction: Store the top of the operand stack into a local variable table
Operand stack instruction
- Pop instruction: Pushes the top element off the stack.
- Dup instruction: Copy and push the top element on the stack.
- The swap directive: Swaps the values of two elements.
Operation instruction
- The add instruction: add
- Sub instruction: subtraction
- Mul instruction: multiply
- Div instruction: division
- Rem instruction: remainder
- Neg instruction: negative
- And instruction: logic and
- Or instruction: logical or
- Xor instruction: logical XOR
Type conversion instruction
- X2y: Converts x to y
Control transfer instruction
- Ifxxx: conditional transfer instruction (XXX is a condition, for example eq is equal, so ifeq is if equal)
- Tableswitch/lookupswitch: compound conditional transfer instruction
- Goto/GOTO_W/JSR/JSR_W/RET: unconditional transfer instruction
Method call instruction
- Invokexxx: Invoke a method of type XXX.