Heap data management for limited local memory(LLM) multi-core processors

Patent metadata

Field	Value
Publication number	US-9513886-B2
Application number	US-201414166220-A
Country	US
Kind code	B2
Filing date	Jan 28, 2014
Priority date	Jan 28, 2013
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

A compiler tool-chain may automatically compile an application to execute on a limited local memory (LLM) multi-core processor by including automated heap management transparently to the application. Management of the heap in the LLM for the application may include identifying access attempts to a program variable, transferring the program variable to the LLM, when not already present in the LLM, and returning a local address for the program variable to the application. The application then accesses the program variable using the local address transparently without knowledge about data in the LLM. Thus, the application may execute on a LLM multi-core processor as if the LLM multi-core processor has an unlimited heap space.

First claim

What is claimed is:

1. A method, comprising:
traversing a plurality of statements in a basic block of an application;
determining whether a statement of the plurality of statements includes a memory reference;
when the statement includes a memory references, inserting a translation statement before the statement;
determining whether the statement includes a reference to variable including a pointer to a pointer; and
when the statement includes a pointer to a pointer, converting the variable to a first new variable and a second new variable, wherein the second new variable is a pointer to the first new variable.

2. The method of claim 1 , in which the translation statement comprises a statement to look up a global address in a heap management data structure.

3. The method of claim 2 , further comprising:
determining whether a heap object pointed to by the global address is present in a limited local memory (LLM); and
when the heap object is not present in the limited local memory (LLM), fetching the heap object from a global memory to the limited local memory (LLM).

4. The method of claim 3 , further comprising returning a local address to the heap object for access to the heap object by the statement.

5. The method of claim 1 , in which the step of converting the variable comprises converting a C statement to a GIMPLE IR statement.

6. A computer program product, comprising:
a non-transitory computer readable medium comprising code to execute the steps comprising:
traversing a plurality of statements in a basic block of an application;
determining whether a statement of the plurality of statements includes a memory reference;
when the statement includes a memory references, inserting a translation statement before the statement;
determining whether the statement includes a reference to variable including a pointer to a pointer; and
when the statement includes a pointer to a pointer, converting the variable to a first new variable and a second new variable, wherein the second new variable is a pointer to the first new variable.

7. The computer program product of claim 6 , in which the translation statement comprises a statement to look up a global address in a heap management data structure.

8. The computer program product of claim 7 , in which the medium further comprises code to execute the steps comprising:
determining whether a heap object pointed to by the global address is present in a limited local memory (LLM); and
when the heap object is not present in the limited local memory (LLM), fetching the heap object from a global memory to the limited local memory (LLM).

9. The computer program product of claim 8 , in which the medium further comprises code to execute the step of returning a local address to the heap object for access to the heap object by the statement.

10. An apparatus, comprising:
a memory; and
a processor coupled to the memory, wherein the processor is configured to execute the steps comprising:
traversing a plurality of statements in a basic block of an application stored in the memory;
determining whether a statement of the plurality of statements includes a memory reference;
when the statement includes a memory references, inserting a translation statement before the statement;
determining whether the statement includes a reference to variable including a pointer to a pointer; and
when the statement includes a pointer to a pointer, converting the variable to a first new variable and a second new variable, wherein the second new variable is a pointer to the first new variable.

11. The apparatus of claim 10 , in which the translation statement comprises a statement look up a global address in a heap management data structure.

12. The apparatus of claim 11 , in which the processor is further configured to execute the steps comprising:
determining whether a heap object pointed to by the global address is present in a limited local memory (LLM); and
when the heap object is not present in the limited local memory (LLM), fetching the heap object from a global memory to the limited local memory (LLM).

13. The apparatus of claim 12 , in which the processor is further configured to execute the step of returning a local address to the heap object for access to the heap object by the statement.

Assignees

• Bai Ke
• Shrivastava Aviral
• Univ Arizona State

Inventors

• Bai Ke
• Shrivastava Aviral

Classifications

• G06F8/4442 Primary

  Reducing the number of cache misses; Data prefetching (cache prefetching G06F12/0862) · CPC title

• G06F12/0862

  with prefetch · CPC title