Instructions in the Java Virtual Machine consist of a byte long number (opcode) that represents the meaning of a particular operation, followed by zero or more parameters (operands) that represent the required parameters of the operation. Bytecode instruction set is an instruction set architecture with distinct characteristics and prominent advantages and disadvantages. Because the length of Java virtual machine opcodes is limited to one byte, the total number of opcodes in the instruction set cannot exceed 256.

Loading and storing instructions

  • Loads a local variable into the action stack

    Iload, iload_<n>, lload, lload_<n>, fload, fload_<n>, dload, dload_<n>, aload, aload_<n>

  • Stores a value from the operand stack to the local variable table

    Fstore, fstore_<n>, dstore, dstore_<n>, astore, astore_<n>, istore, istore_<n>, lstore, lstore_<n>

  • Loads a constant into the operand stack

    Bipush, sipush, LDC, ldc_w, ldc2_w, aconst_null, iconst_ml, iconst_< I >, lconst_<l>, fconst_<f>, dconst_<d>

  • Expand local variable table access index instruction

    wide

Operation instruction

  • Add instruction

    IADD, LADD, FADD, DADD

  • Subtraction instructions

    ISUB, LSUB, FSUB, DSUB

  • Multiplication instructions

    IMUL, LMUL, FMUL, DMUL

  • Division instructions

    IDIV, LDIV, FDIV, DDIV

  • For more instruction

    IREM, LREM, FREM, DREM

  • Take the instruction

    INEG, LNEG, FNEG, DNEG

  • Displacement instructions

    Ishl, ishr, iushr, LSHL, lshe, lushr

  • By bits or instructions

    Ior, lor

  • By bit and instruction

    Iand, land

  • Bit by bit XOR instruction

    Ixor, lxor

  • Local variable increment instruction

    iinc

  • More instructions

    DCMPG, DCMPL, FCMPG, FCMPL, LCMP