Managing aliasing constraints

Patent metadata

Field	Value
Publication number	US-10101979-B2
Application number	US-201213545649-A
Country	US
Kind code	B2
Filing date	Jul 10, 2012
Priority date	Jul 12, 2011
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

An illustrative embodiment of a computer-implemented process for managing aliasing constraints, identifies an object to form an identified object, identifies a scope of the identified object to form an identified scope, and assigns a unique value to the identified object within the identified scope. The computer-implemented process further demarcates an entrance to the identified scope, demarcates an exit to the identified scope, optimizes the identified object using a property of the identified scope and associated aliasing information, tracks the identified object state to form tracked state information; and uses the tracked state information to update the identified object.

First claim

What is claimed is:

1. A computer-implemented method of compiling a source file of a computer program using a compiler, comprising:
identifying, within the source file, a restricted pointer to an original object to form an identified object, the restricted pointer having an identified scope with an entrance and one or more exits;
generating, by the compiler, a unique value that identifies the identified object within bounds of the identified scope; and
replacing, at the entrance, a pointer assignment of the restricted pointer with a copyin assignment including the unique value.

2. The method of claim 1 , further comprising:
inserting, at each of the one or more exits, a copyout directive including the unique value.

3. The method of claim 2 , further comprising:
pairing, by the compiler and based upon the unique value, the copyin assignment with the one or more copyout directives.

4. The method of claim 1 , further comprising:
optimizing, using regular pointer analysis, references of the restricted pointer using uniqueness properties of the restricted pointer in the identified scope.

5. The method of claim 1 , further comprising:
tracking state information of the identified object; and
synchronizing the original object with the identified object using the tracked state information.

6. The method of claim 1 , further comprising:
using an aggressive aliasing on code with the identified scope in place of a conservative aliasing.

7. The method of claim 1 , further comprising:
expanding the copyin assignment into a direct pointer assignment; and
expanding the copyout directive as a NOP.

8. A computer hardware system including a compiler configured to compile a source file of a computer program, comprising:
a hardware processor configured to initiate the following executable instructions:
identifying, within the source file, a restricted pointer to an original object to form an identified object, the restricted pointer having an identified scope with an entrance and one or more exits;
generating, by the compiler, a unique value that identifies the identified object within bounds of the identified scope; and
replacing, at the entrance, a pointer assignment of the restricted pointer with a copyin assignment including the unique value.

9. The system of claim 8 , wherein the hardware processor is further configured to initiate the following executable instruction:
inserting, at each of the one or more exits, a copyout directive including the unique value.

10. The system of claim 9 , wherein the hardware processor is further configured to initiate the following executable instruction:
pairing, by the compiler and based upon the unique value, the copyin assignment with the one or more copyout directives.

11. The system of claim 8 , wherein the hardware processor is further configured to initiate the following executable instruction:
optimizing, using regular pointer analysis, references of the restricted pointer using uniqueness properties of the restricted pointer in the identified scope.

12. The system of claim 8 , wherein the hardware processor is further configured to initiate the following executable instructions:
tracking state information of the identified object; and
synchronizing the original object with the identified object using the tracked state information.

13. The system of claim 8 , wherein the hardware processor is further configured to initiate the following executable instruction:
using an aggressive aliasing on code with the identified scope in place of a conservative aliasing.

14. The system of claim 8 , wherein the hardware processor is further configured to initiate the following executable instructions:
expanding the copyin assignment into a direct pointer assignment; and
expanding the copyout directive as a NOP.

15. A computer program product, comprising:
a computer hardware storage device having computer executable program code stored therein for compiling a source file of a computer program,
the computer executable program code, which when executed by a computer hardware system including a compiler, causes the computer hardware system to perform:
identifying, within the source file, a restricted pointer to an original object to form an identified object, the restricted pointer having an identified scope with an entrance and one or more exits;
generating, by the compiler, a unique value that identifies the identified object within bounds of the identified scope; and
replacing, at the entrance, a pointer assignment of the restricted pointer with a copyin assignment including the unique value.

16. The computer program product of claim 15 , wherein the computer executable program code further causes the computer hardware system to perform:
inserting, at each of the one or more exits, a copyout directive including the unique value.

17. The computer program product of claim 16 , wherein the computer executable program code further causes the computer hardware system to perform:
pairing, by the compiler and based upon the unique value, the copyin assignment with the one or more copyout directives.

18. The computer program product of claim 15 , wherein the computer executable program code further causes the computer hardware system to perform:
optimizing, using regular pointer analysis, references of the restricted pointer using uniqueness properties of the restricted pointer in the identified scope.

19. The computer program product of claim 15 , wherein the computer executable program code further causes the computer hardware system to perform:
tracking state information of the identified object; and
synchronizing the original object with the identified object using the tracked state information.

20. The computer program product of claim 15 , wherein the computer executable program code further causes the computer hardware system to perform:
using an aggressive aliasing on code with the identified scope in place of a conservative aliasing.

Assignees

• Cui Shimin
• Silvera Raul E
• IBM

Inventors

• Cui Shimin
• Silvera Raul E

Classifications

• G06F8/443 Primary

  Optimisation · CPC title