Optimizing program by reusing execution result of subclass test function

• US 8,793,672 B2
• Filed: 03/07/2012
• Issued: 07/29/2014
• Est. Priority Date: 03/09/2011
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ogasawara, Takeshi
• Primary Examiner(s): Zhen, Li B
• Assistant Examiner(s): CHEN, SEN THONG
• Application Number:
  US13/413,709
• Publication Number:
  US 20120233597A1
• Time in Patent Office: 874 Days
• Field of Search: None
• US Class Current: 717/151
• CPC Class Codes: G06F 8/36 Software reuse
• CPC Class Codes: G06F 8/4441 Reducing the execution time required by the program code

Abstract

A technique for optimizing a program by reusing an execution result of a subclass test function. It includes a reusability determining unit to determine reusability of code of a subclass test function based on whether access to a global memory includes only access for reading out type information specified in a function call, a profiling unit configured to store an execution result of code determined to be reusable and specified information in a storage device in association with actually accessed type information, a reuse processing unit configured to reuse, in response to detection of a function call for calling the code determined to be reusable, the execution result on condition that the pieces of specified information specified in the function calls match, and a monitoring unit configured to monitor the type information associated with the execution result and prohibit reuse of the execution result if the type information is changed.

Claims

1. A method for optimizing a program, comprising:

determining reusability of code called by a function call of a subclass test function included in an execution-target program, on the basis of whether or not access to a global memory within said code includes only access for reading out type information specified in said function call and information traceable from said type information;

storing an execution result of code determined to be reusable and specified information specified in said function call of said code in a storage device as profile information of said code, in association with type information actually accessed within said code;

reading out, in response to detection of said function call of the subclass test function that calls the code determined to be reusable, the profile information of said code from said storage device, and reusing said execution result of said profile information provided that the specified information of said profile information matches specified information specified in said detected function call; and

monitoring said type information associated with said execution result included in said profile information stored in said storage device, and prohibiting, in response to a change made to said type information, reuse of said execution result associated with said type information, wherein said prohibiting said reuse of the execution result includes deleting said profile information associated with said change made to said type information and inserting an instruction sequence that invalidates said reuse of said execution result,

wherein a processor coupled to a memory device is configured to perform;

the determining, the storing, the reading out and the monitoring.

2. The method according to claim 1, wherein said step of storing further stores a namespace used at run time as said profile information of said code determined to be reusable together with said execution result of said code, and said step of reusing further confirms that said detected function call calls said code determined to be reusable by confirming that said namespace of the read out profile information matches a current namespace.

3. The method according to claim 2, wherein said step of reusing includes a step of generating, as compiled code, reuse code that reuses said execution result of said profile information, provided that the specified information specified in said detected function call matches the specified information of said profile information.

4. The method according to claim 3, further comprising:

accessing pre-registered manipulation code for changing type information, and inserting, into said pre-registered manipulation code, an instruction sequence for invalidating said reuse code that reuses said execution result provided that said type information associated with said reused execution result is changed, wherein said step of prohibiting is performed by execution of said instruction sequence.

5. The method according to claim 1, wherein said code of said subclass test function whose execution result is to be stored for the purpose of reuse is limited to code of a default subclass test function.

6. The method according to claim 5, further comprising:

generating a listener that corresponds to a change event of said type information associated with said execution result stored as said profile information and that invalidates, in response to occurrence of said change event, said profile information corresponding to said changed type information, wherein the step of prohibiting is performed by execution of said listener.

7. The method according to claim 5, further comprising:

generating a listener that corresponds to a change event of said type information associated with said reused execution result and that invalidates, in response to occurrence of said change event, said reuse code that reuses said execution result, wherein said step of prohibiting is performed by execution of said listener.

8. The method according to claim 2, wherein, in said step of determining, all access instructions to said global memory from said code for which reusability is determined are retrieved, and it is statically determined that said code is reusable provided that all of said retrieved access instructions are regarding access for reading out said type information specified in said function call of said subclass test function and said information traceable from said type information.

9. The method according to claim 2, wherein, in said step of determining, computer determination code is generated in which values of an object and said type information that are specified in said function call of said subclass test function are propagated on said code for which reusability is determined, and it is dynamically determined that said code is reusable provided that all access made to said global memory during run time of said generated determination code is access for reading out said type information.

10. The method according to claim 2, further comprising:

creating, for said code determined to be reusable, a template for collecting an address of type information accessed by execution of said code, wherein said profile information is generated using a result of execution of said template.

11. The method according to claim 2, wherein said execution-target program is bytecode generated by a Python interpreter from a source program written in Python.

12. A computer program product reusing an execution result of a subclass test function included in an execution-target program, the computer program product comprising:

a non-transitory computer readable storage medium having computer readable non-transient program code embodied therein, the computer readable program code comprising;

computer readable program code configured to perform the steps of a method according to claim 1.

13. A computer program product reusing an execution result of a subclass test function included in an execution-target program, the computer program product comprising:

a non-transitory computer readable storage medium having computer readable non-transient program code embodied therein, the computer readable program code comprising;

computer readable program code configured to perform the steps of a method according to claim 2.