Initializing a data structure for use in predicting table of contents pointer values

• US 10,705,973 B2
• Filed: 09/19/2017
• Issued: 07/07/2020
• Est. Priority Date: 09/19/2017
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Gschwind, Michael K., Salapura, Valentina
• Primary Examiner(s): Bataille, Pierre Miche
• Application Number:
  US15/708,235
• Publication Number:
  US 20190087346A1
• Time in Patent Office: 1,022 Days
• Field of Search: 711209
• CPC Class Codes: G06F 12/0223 User address space allocation, e.g. contiguous or non contiguous base addressing
• CPC Class Codes: G06F 12/0292 using tables or multilevel address translation means G06F12/023 takes precedence; address translation in virtual memory systems G06F12/10
• CPC Class Codes: G06F 12/0875 with dedicated cache, e.g. instruction or stack
• CPC Class Codes: G06F 12/1009 using page tables, e.g. page table structures
• CPC Class Codes: G06F 2212/1024 Latency reduction
• CPC Class Codes: G06F 2212/45 Caching of specific data in cache memory
• CPC Class Codes: G06F 2212/452 Instruction code
• CPC Class Codes: G06F 8/41 Compilation
• CPC Class Codes: G06F 8/447 Target code generation
• CPC Class Codes: G06F 9/3004 to perform operations on memory
• CPC Class Codes: G06F 9/30101 Special purpose registers
• CPC Class Codes: G06F 9/3017 Runtime instruction translation, e.g. macros
• CPC Class Codes: G06F 9/3844 using dynamic branch prediction, e.g. using branch history tables
• CPC Class Codes: G06F 9/44521 Dynamic linking or loading; Link editing at or after load time, e.g. Java class loading
• CPC Class Codes: G06F 9/455 Emulation; Interpretation; Software simulation, e.g. virtualisation or emulation of application or operating system execution engines

Abstract

Initializing a data structure for use in predicting table of contents (TOC) pointer values. A request to load a module is obtained. Based on the loaded module, a pointer value for a reference data structure is determined. The pointer value is stored in a reference data structure tracking structure, and used to access a variable value for a variable of the module.

Claims

1. A computer program product for facilitating processing within a computing environment, the computer program product comprising:

a computer readable storage medium readable by a processing circuit and storing instructions for performing a method comprising;

obtaining, by a processor, a request to load a module;

determining, based on the module loaded, a pointer value for a reference data structure;

storing the pointer value in a reference data structure tracking structure, wherein the reference data structure tracking structure is a reference data structure pointer cache, and wherein the reference data structure pointer cache comprises an address field to include an address for which the pointer value is being set and a pointer value field to include the pointer value, the address field including the address of the module; and

using the pointer value to access a variable value for a variable of the module.

2. The computer program product of claim 1, wherein the reference data structure pointer cache further includes another field to indicate one or more functions that do not initialize a pointer value register.

3. The computer program product of claim 1, wherein the reference data structure pointer cache further includes a usage tracking field to be used in selecting an entry from the reference data structure pointer cache to be replaced.

4. The computer program product of claim 1, wherein the reference data structure pointer cache comprises a plurality of address fields to specify a range of addresses for which the pointer value is associated.

5. The computer program product of claim 1, wherein the reference data structure tracking structure is an in-memory table.

6. The computer program product of claim 1, wherein the determining the pointer value comprises determining the pointer value from a relative offset of the module.

7. A computer system for facilitating processing within a computing environment, the computer system comprising:

a memory; and

a processor in communication with the memory, wherein the computer system is configured to perform a method, said method comprising;

obtaining, by a processor, a request to load a module;

determining, based on the module loaded, a pointer value for a reference data structure;

storing the pointer value in a reference data structure tracking structure, wherein the reference data structure tracking structure is a reference data structure pointer cache, and wherein the reference data structure pointer cache comprises an address field to include an address for which the pointer value is being set and a pointer value field to include the pointer value, the address field including the address of the module; and

using the pointer value to access a variable value for a variable of the module.

8. The computer system of claim 7, wherein the reference data structure pointer cache further includes a usage tracking field to be used in selecting an entry from the reference data structure pointer cache to be replaced.

9. The computer system of claim 7, wherein the reference data structure tracking structure is an in-memory table.

10. The computer system of claim 7, wherein the reference data structure pointer cache further includes another field to indicate one or more functions that do not initialize a pointer value register.

11. The computer system of claim 7, wherein the reference data structure pointer cache comprises a plurality of address fields to specify a range of addresses for which the pointer value is associated.

12. The computer system of claim 7, wherein the determining the pointer value comprises determining the pointer value from a relative offset of the module.