Method and apparatus for executing instruction of java virtual machine

• US 20060253847A1
• Filed: 04/11/2006
• Published: 11/09/2006
• Est. Priority Date: 04/21/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Romanovskiy, Alexey
• Granted Patent: US 7,725,879 B2
• Time in Patent Office: Days
• US Class Current: 717/153
• CPC Class Codes: G06F 9/45516 Runtime code conversion or optimisation

Abstract

A method and apparatus for executing an instruction of a Java virtual machine are provided. The method includes extracting a bytecode of a method of a Java class, transforming the bytecode into a second code which comprises information regarding a location of an opcode handler and uses 16-bit memory elements, the opcode handler performing an operation corresponding to an opcode included in the bytecode, and executing the second code.

Claims

1. A method of executing an instruction of a Java virtual machine, the method comprising:

extracting a bytecode of a method of a Java class;

transforming the bytecode into a second code which comprises information regarding a location of an opcode handler and uses 16-bit memory elements, the opcode handler performing an operation corresponding to an opcode included in the bytecode; and

executing the second code.

2. The method of claim 1, wherein the execution of the second code comprises:

linking the second code to a runtime state;

initializing a result of the linking to be executable; and

executing a result of the initializing.

3. The method of claim 2, wherein the linking of the second code comprises verifying the second code with reference to a table which comprises the information regarding the location of the opcode handler and the opcode corresponding to the opcode handler.

4. The method of claim 1, wherein the information regarding the location of the opcode handler is an offset of the opcode handler.

5. The method of claim 1, wherein the transforming of the bytecode comprises transforming an operand of the bytecode into a second operand using 16-bit memory elements, wherein the operand comprises at least one byte.

6. The method of claim 5, wherein the transforming of the operand of the bytecode comprises shifting the operand of the bytecode to the left by two bits.

7. The method of claim 1, wherein the transforming of the bytecode comprises transforming an operand of the bytecode into a second operand using 16-bit memory elements by combining consecutive bytes constituting the operand.

8. The method of claim 7, wherein the transforming of the operand of the bytecode comprises:

combining consecutive bytes constituting the operand by using at least one of an OR operation and a shift operation; and

shifting a result of the combining to the left by two bits.

9. The method of claim 7, wherein, if the operand of the bytecode is an offset, the second operand is obtained by adding the offset to a base address.

10. The method of claim 1, wherein if opcode of the bytecode uses a wide operand, the transforming of the bytecode comprises transforming the opcode without using the wide operand.

11. A Java virtual machine comprising:

a bytecode extraction unit which extracts a bytecode of a method of a Java class;

a second code transformation unit which transforms the bytecode into a second code which comprises information regarding a location of an opcode handler and uses 16-bit memory elements, the opcode handler performing an operation corresponding to an opcode included in the bytecode; and

an instruction execution unit which executes the second code.

12. The Java virtual machine of claim 11, further comprising:

a linking unit which links the second code into a runtime state; and

an initialization unit which initializes the linked second code to be executable.

13. The Java virtual machine of claim 11, wherein the linking unit verifies the second code with reference to a table which comprises the information regarding the location of the opcode handler and the opcode corresponding to the opcode handler.

14. The Java virtual machine of claim 11, wherein the information regarding the location of the opcode handler is an offset of the opcode handler.

15. The Java virtual machine of claim 11, wherein the second code transformation unit transforms an operand of the bytecode into a second operand using 16-bit memory elements.

16. The Java virtual machine of claim 11, wherein the second code transformation unit shifts an operand of the bytecode to the left by two bits.

17. The Java virtual machine of claim 11, wherein the second code transformation unit transforms an operand of the bytecode into a second operand using 16-bit memory elements by combining consecutive bytes constituting the operand.

18. The Java virtual machine of claim 11, wherein if the operand of the bytecode is an offset, the second operand is obtained by adding the offset to a base address.

19. The Java virtual machine of claim 11, wherein the second code transformation unit combines consecutive bytes constituting the operand of the bytecode using at least one of an OR operation and a shift operation, and shifts a result of the combining to the left by two bits.

20. The Java virtual machine of claim 11, wherein if the opcode of the bytecode uses a wide operand, the second code transformation unit transforms the opcode without using the wide operand.

21. A recording medium having a computer readable program recorded therein, the program for executing a method of executing an instruction of a Java virtual machine, the method comprising:

extracting a bytecode of a method of a Java class;

transforming the bytecode into a second code which comprises information regarding a location of an opcode handler and uses 16-bit memory elements, the opcode handler performing an operation corresponding to an opcode included in the bytecode; and

executing the second code.