Jump to the class file directory using
javap -c StringTest.class -> p.txt
1
Command to output the compiled file to the p.txt file
Stack and local variable manipulation
An instruction to push a constant onto the stack
Aconst_null pushes the NULL object reference onto the stack
Iconst_m1 pushes a constant of type int -1
Iconst_0 pushes the constant 0 of type int
Iconst_1 pushes a constant of type int 1
Iconst_2 pushes a constant of type 2 int
Iconst_3 pushes a constant of type int 3
Iconst_4 pushes a constant of type 4 int
Iconst_5 pushes the constant 5 of type int
Lconst_0 pushes the constant 0 of type long onto the stack
Lconst_1 pushes a constant of type 1 of long onto the stack
Fconst_0 pushes the constant 0 of type float onto the stack
Fconst_1 pushes the constant of type float 1 onto the stack
Dconst_0 pushes the constant 0 of type double onto the stack
Dconst_1 pushes the constant of type 1 double onto the stack
Bipush pushes an 8-bit signed integer onto the stack
Sipush pushes 16-bit signed integers onto the stack
The LDC pushes items in the constant pool onto the stack
Ldc_w pushes items in the constant pool (using wide indexes)
Ldc2_w pushes items of type long or double in the constant pool (using wide indexes)
An instruction to load values from local variables in the stack
Iload loads int values from local variables
Lload loads values of type long from local variables
Fload loads a float value from a local variable
Dload loads values of type double from local variables
Aload loads reference type values from local variables (RefernCE)
Iload_0 loads int values from local variable 0
Iload_1 loads int values from local variable 1
Iload_2 loads int values from local variable 2
Iload_3 loads int values from local variable 3
Lload_0 loads a value of type long from local variable 0
Lload_1 loads a value of type long from local variable 1
Lload_2 loads a value of type long from local variable 2
Lload_3 loads a value of type long from local variable 3
Fload_0 loads a value of type float from local variable 0
Fload_1 loads a value of type float from local variable 1
Fload_2 loads a value of type float from local variable 2
Fload_3 loads a value of type float from local variable 3
Dload_0 loads a value of type double from local variable 0
Dload_1 loads a value of type double from local variable 1
Dload_2 loads a value of type double from local variable 2
Dload_3 loads a value of type double from local variable 3
Aload_0 loads the reference type value from local variable 0
Aload_1 loads the reference type value from local variable 1
Aload_2 loads the reference type value from local variable 2
Aload_3 loads the reference type value from local variable 3
Iaload loads int values from arrays
Laload loads values of type long from an array
Faload loads a float value from an array
Daload loads a double value from an array
Aaload loads reference type values from an array
Baload loads byte or Boolean values from an array
Caload loads a char value from an array
Saload loads short values from an array
An instruction to store a stack value to a local variable
Istore stores int values into local variables
Lstore stores values of type long into local variables
Fstore stores a float value into a local variable
Dstore stores values of type double into local variables
Astore stores a reference type or returnAddress type value into a local variable
Istore_0 stores a value of type int into the local variable 0
Istore_1 stores a value of type int to the local variable 1
Istore_2 stores a value of type int to local variable 2
Istore_3 stores a value of type int to the local variable 3
Lstore_0 stores a value of type long into the local variable 0
Lstore_1 stores a value of type long into the local variable 1
Lstore_2 stores a value of type long into local variable 2
Lstore_3 stores a value of type long into local variable 3
Fstore_0 stores a value of type float into the local variable 0
Fstore_1 stores a float value into the local variable 1
Fstore_2 stores a value of type float into local variable 2
Fstore_3 stores a value of type float into local variable 3
Dstore_0 stores a value of type double into the local variable 0
Dstore_1 stores a value of type double into the local variable 1
Dstore_2 stores a value of type double into local variable 2
Dstore_3 stores a value of type double into local variable 3
Astore_0 stores a reference type or returnAddress type value into the local variable 0
Astore_1 stores a reference type or returnAddress type value into the local variable 1
Astore_2 stores a reference type or returnAddress type value into local variable 2
Astore_3 stores the reference type or returnAddress type value into the local variable 3
Iastore stores int values into arrays
Lastore stores values of type long into an array
Fastore stores a float value into an array
Dastore stores a value of type double into an array
Aastore stores reference type values into an array
Bastore stores byte or Boolean values into arrays
Castore stores char values into arrays
Sastore stores short values into an array
Wide instruction
Wide extends the local variable index with additional bytes
Generic (no type) stack operation
Nop does nothing
Pop Pops a word at the top of the stack
Pop2 pops two words at the top of the stack
Dup copies the top of the stack one word long
Dup_x1 copies the one word at the top of the stack and then pushes the copy along with the original popup of two words
Dup_x2 copies the one word at the top of the stack, and then pushes the copied content onto the stack along with the original pop-up three words
Dup2 copies the top two words of the stack
Dup2_x1 copies the top two words of the stack and then pushes the copied contents onto the stack along with the original pop-up three words
Dup2_x2 copies the top two words of the stack and then pushes the copied contents onto the stack along with the original pop-up four words
Swap swaps the top two words of the stack
Type conversion
I2l converts int to long
I2f converts int data to float
I2d converts an int to a double
L2i converts long data to int
L2f converts long data to float
L2d converts long data to double
F2i converts a float to an int
F2l converts data of type float to long
F2d converts a float to a double
D2i converts a double to an int
D2l converts a double to a long
D2f converts data of type double to float
I2b converts int data to byte
I2c converts int data to char
I2s converts int data to short
Integer arithmetic
Iadd performs addition of int type
Ladd performs addition of type long
Isub performs subtraction of type int
Lsub performs subtraction of type long
Imul performs multiplication of type int
Lmul performs multiplication of type long
Idiv performs division of type int
Ldiv performs division of type long
Irem computes the remainder of an int division
Lrem computes the remainder of a division of type long
Ineg Reverses the value of an int
Lneg inverts a value of type long
Iinc adds a constant value to a local variable of type int
Logical operations
Shift operation
Ishl performs a shift of type int to the left
LSHL performs a shift to the left of type long
Ishr performs a shift to the right of type int
LSHR performs a shift to the right of type LONG
Iushr performs a logical shift to the right of int
Lushr performs a logical shift to the right of type LONG
Bitwise Boolean operation
Iand performs logical and operations on values of int type
Land performs logical and operations on values of type long
Ior performs logical or operations on values of type int
Lor performs logical or operations on values of type long
Ixor performs logical xor operations on values of int type
Lxor performs logical xor operations on values of type long
Floating point arithmetic
Fadd performs float addition
Dadd performs addition of type double
Fsub performs subtraction of type float
Dsub performs subtraction of type double
Fmul performs a float multiplication
Dmul performs multiplication of type double
Fdiv performs a float division
Ddiv performs a division of type double
Frem computes the remainder of a float division
Drem evaluates the remainder of a division of type double
Fneg inverts a value of type float
Dneg inverts a value of type double
Objects and Arrays
Object operation instruction
New Creates a new object
Checkcast Determines that the object is of the given type
Getfield retrieves the field from the object
Putfield Sets the value of a field in an object
Getstatic gets static fields from the class
Putstatic Sets the value of the static field in the class
Instanceof determines whether an object is of a given type
Array manipulation instruction
Newarray allocates a newarray of data members of type basic data
Anewarray allocates anewarray of data members of type reference
Arraylength gets the length of the array
Multianewarray allocates anew multidimensional array
The control flow
Conditional branch instruction
If ifeq equals 0, jump
If ifne is not equal to 0, the system jumps
If iFLT is less than 0, the system jumps
If ifGE is greater than or equal to 0, the system jumps
If ifgt is greater than 0, the system jumps
If ifLE is less than or equal to 0, the system jumps
If_icmpcq Jumps if two ints are equal
If_icmpne Jumps if two ints are not equal
If_icmplt Jumps if one int value is less than another int
If_icmpge Jumps if one int value is greater than or equal to another int
If_icmpgt If one int value is greater than another int value, this command jumps
If_icmple Jumps if one int is less than or equal to another int
Ifnull If equal to null, the jump
Ifnonnull If the value is not null, the system jumps
If_acmpeq Jumps if two object references are equal
If_acmpnc Jumps if two object references are not equal
More instructions
LCMP compares values of type long
FCMPL compares float values (-1 when NaN is encountered)
FCMPG compares values of type float (returns 1 when NaN is encountered)
DCMPL compares values of type double (-1 when NaN is encountered)
DCMPG compares values of type double (returns 1 when NaN is encountered)
Unconditional transfer instruction
Goto Unconditional jump
Goto_w Unconditional jump (wide index)
Table jump instruction
Tableswitch Accesses the hop table based on indexes and hops
Lookupswitch accesses jump tables by key value matching and performs jumps
abnormal
Athrow throws an exception or error
The finally clause
JSR jumps to the subroutine
Jsr_w Jumps to a subroutine (wide index)
The RCT returns from the subroutine
Method calls and returns
Method call instruction
The InvokCVirtual runtime invokes instance methods based on the object’s class
Invokespecial invokes instance methods based on compile-time types
Invokestatic invokes class (static) methods
Invokcinterface invokes interface methods
Method return instruction
Ireturn returns int data from the method
Lreturn returns data of type long from the method
Freturn returns data of type float from the method
Dreturn returns data of type double from the method
Areturn returns referenced type data from the method
Return Returns void from a method
Thread synchronization
Montiorenter enters and retrieves the object monitor
Monitorexit releases and exits the object monitor
JVM instruction mnemonic
Variable to operand stack: ILoad, ILoAD_,lload,lload_,fload,fload_,dload,dload_, ALOad, ALOad_
Operand stack to variables: istore,istore_,lstore,lstore_,fstore,fstore_,dstore,dstor_,astore,astore_
Constant to operand stack: bipush,sipush, LDC, LDC_w, LDC2_W, aconst_NULL, iconst_ML,iconst_, LCONST_, fCONST_, dCONST_
Add: iadd, ladd, fadd, dadd
Reduction: isub, lsub fsub, dsub
Passenger: imul lmul, fmul dmul
In addition: idiv ldiv, fdiv ddiv
Remainder: irem, lrem frem, drem
Take negative: ineg, lneg fneg, dneg
Shift: ishl, LSHR iushr, LSHL, LSHR, lushr
Bitwise or: ior, LOR
Bitwise and: iAND,land
Bitwise xOR: ixOR, lxOR
Type conversion: i2L,i2f, i2D, L2F, l2D, f2D (relaxed numeric conversion)
I2b, i2c, i2s l2i f2i, f2l, d2i, d2l, d2f (narrowing conversion)
Create the class: new
Create a new array: newarray, anewarray multianwarray
Access to the class and class instance domains:, getfield, putfield getstatic, putstatic
The data loaded into the operand stack: baload, caload, saload, iaload, laload, faload, daload, aaload
From the operand stack memory stored in the array: bastore, castore, sastore, iastore, lastore, fastore, dastore, aastore
Gets the arraylength: arraylength
Class instance or array properties: instanceof,checkcast
Operand stack management: POP, POP2, DUP, DUp2, dup_XL, dup2_XL, DUp_x2,dup2_x2,swap
Conditional transfer: ifeq, iflt ifle, ifne, ifgt, ifge, ifnull, ifnonnull, if_icmpeq, if_icmpene,
if_icmplt,if_icmpgt,if_icmple,if_icmpge,if_acmpeq,if_acmpne,lcmp,fcmpl
fcmpg,dcmpl,dcmpg
Compound conditional transfer: Tableswitch,lookupswitch
Unconditional transfer: GOto, GOTO_W, JSR, jSR_W, RET
A convenient method for scheduling objects: Invokevirtual
Invoke the method implemented by the interface: InvokeInterface
Invoke the instance method that requires special processing: Invokespecial
Invoke the static method in the named class: Invokestatic
Returns: ireturn, lreturn freturn, dreturn, areturn, return
Exception: athrow
The finally keyword is implemented using JSR, jSR_w,ret
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