Granted Patent B2

US 12,578,939 · App. 18/464,636 · Granted Mar 17, 2026

Inventors: Vijay Sundaresan (North York, CA); Daryl James Maier (Canada, CA); Krishna Nandivada Venkata (Chennai, IN); Manas Thakur (Mumbai, IN)

Assignees: INTERNATIONAL BUSINESS MACHINES CORPORATION; INDIAN INSTITUTE OF TECHNOLOGY MADRAS (IIT MADRAS)

G06F8/41G06F8/315

Abstract

Claims (39)

1 . A computer-implemented method, comprising:

receiving, by a processor set, source code including at least one programmed method and at least one reference within the at least one programmed method that accesses at least one field of at least one object;

determining, by the processor set, that the at least one object is local to a thread without reference to the at least one object outside the thread and that the at least one field of the at least one object is scalarizable over a region of the at least one programmed method;

performing, by the processor set, scalarization of the at least one field of the at least one object over the region of the at least one programmed method; and

outputting, by the processor set, optimized object code with the at least one field of the at least one object scalarized over the region of the at least one programmed method and with another field of the at least one object unscalarized in a different region of the at least one programmed method.

2 . The computer-implemented method of claim 1 , further comprising identifying that the at least one object is a thread-local object.

3 . The computer-implemented method of claim 2 , wherein the identifying comprises performing inter-procedural analysis of the at least one programmed method.

4 . The computer-implemented method of claim 1 , further comprising identifying that the at least one object is referenced by local variables with singleton points-to sets.

5 . The computer-implemented method of claim 4 , wherein the identifying comprises performing points-to analysis that identifies a set of objects the local variables can point to.

6 . The computer-implemented method of claim 1 , wherein the determining comprises determining that the at least one object is not accessed via a field of another object.

7 . The computer-implemented method of claim 1 , further comprising determining that the another field of the at least one object is not scalarizable in the different region of the at least one programmed method.

8 . The computer-implemented method of claim 1 , further comprising determining that a cost of scalarizing the at least one field of the at least one object does not exceed a cost of not scalarizing the at least one field.

9 . The computer-implemented method of claim 8 , wherein the determining comprises determining that the at least one field is accessed at least twice.

10 . The computer-implemented method of claim 1 , further comprising determining that a cost of scalarizing the another field of the at least one object exceeds a cost of not scalarizing the another field.

11 . The computer-implemented method of claim 1 , wherein the determining comprises identifying critical points comprising a start-point and a set of endpoints for the at least one object within the at least one programmed method.

12 . The computer-implemented method of claim 11 , wherein the identifying comprises identifying a critical predecessor set for the set of endpoints of the critical points.

13 . A computer program product comprising one or more computer readable storage media having program instructions collectively stored on the one or more computer readable storage media, the program instructions executable to:

receive source code including at least one programmed method and at least one reference within the at least one programmed method that accesses at least one field of at least one object;

identify critical points comprising a start-point and a set of endpoints for the at least one object within the at least one programmed method;

identify a critical predecessor set for the set of endpoints of the critical points of the at least one object within the at least one programmed method;

determine that the at least one object is local to a thread without reference to the at least one object outside the thread and that at least one field access of the at least one object in the critical predecessor set of the at least one programmed method is scalarizable;

perform scalarization of the at least one field access of the at least one object in the critical predecessor set of the at least one programmed method; and

output optimized object code with the at least one field access of the at least one object scalarized in the critical predecessor set of the at least one programmed method and with another field access of the at least one object not scalarized in the at least one programmed method that is not in the critical predecessor set in the at least one programmed method.

14 . The computer program product of claim 13 , wherein the program instructions are further executable to determine that a cost of scalarizing the at least one field access of the at least one object in the critical predecessor set of the at least one programmed method does not exceed a cost of not scalarizing the at least one field access.

15 . The computer program product of claim 13 , wherein the determining comprises determining that the another field access of the at least one object not in the critical predecessor set is not scalarizable.

16 . The computer program product of claim 13 , wherein the determining comprises:

determining the another field access is not thread-escaping;

determining the another field access is not referenced by local variables with non-singleton points-to sets; and

determining the another field access is not accessed via a field of another object.

17 . A system comprising:

a processor set, a computer readable memory, one or more computer readable storage media, and program instructions collectively stored on the one or more computer readable storage media, the program instructions executable to:

receive source code including at least one programmed method and at least one reference within the at least one programmed method that accesses at least one field of at least one object;

determine that the at least one object is local to a thread without reference to the at least one object outside the thread and that the at least one field of the at least one object is scalarizable over a region of the at least one programmed method;

determine that a cost of scalarizing the at least one field of the at least one object does not exceed a cost of not scalarizing the at least one field;

perform scalarization of the at least one field of the at least one object over the region of the at least one programmed method; and

output optimized object code with the at least one field of the at least one object scalarized over the region of the at least one programmed method and with another field of the at least one object unscalarized in a different region of the at least one programmed method.

18 . The system of claim 17 , wherein the program instructions are further executable to identify that the another field of the at least one object is a thread-escaping.

19 . The system of claim 17 , wherein the program instructions are further executable to identify that the another field of the at least one object is referenced by local variables with non-singleton points-to sets.

20 . The system of claim 17 , wherein the program instructions are further executable to identify that the another field of the at least one object is accessed via a field of another object.

Assignments (2)

Continuity (1)

References Cited (26)