Cache control device for prefetching using pattern analysis processor and prefetch instruction and prefetching method using cache control device

Patent metadata

Field	Value
Publication number	US-9886384-B2
Application number	US-201514931019-A
Country	US
Kind code	B2
Filing date	Nov 3, 2015
Priority date	May 3, 2013
Publication date	Feb 6, 2018
Grant date	Feb 6, 2018

Abstract

The present examples relate to prefetching, and to a cache control device for prefetching and a prefetching method using the cache control device, wherein the cache control device analyzes a memory access pattern of program code, inserts, into the program code, a prefetching command generated by encoding the analyzed access pattern, and executes the prefetching command inserted into the program code in order to prefetch data into a cache, thereby maximizing prefetching efficiency.

First claim

What is claimed is:

1. A cache control device comprising:
a pattern analysis processor configured to analyze a memory access pattern of program code;
a code conversion processor configured to generate a prefetch instruction by encoding the analyzed memory access pattern, and to insert the generated prefetch instruction into the program code;
a prefetch processor configured to prefetch data into a cache, in response to an execution of the prefetch instruction inserted into the program code; and
an optimization processor configured to change a plurality of data to be simultaneously used together into a single array structure, such that the plurality of data are all prefetched together into the cache.

2. The cache control device of claim 1 , further comprising:
a prefetch table configured to store input parameters of the prefetch instruction,
wherein the prefetch processor executes the prefetch instruction inserted into the program code, based on the input parameters.

3. The cache control device of claim 1 , wherein the prefetch processor prefetches data according to a regular pattern, in response to the execution of the prefetch instruction inserted into the program code.

4. The cache control device of claim 1 , wherein the pattern analysis processor compiles the program code into binary code, and analyzes the memory access pattern by profiling the binary code.

5. The cache control device of claim 1 , wherein the prefetch instruction comprises, as the input parameters, at least one identifier (ID) for identifying a memory access pattern of the program code, a program counter (PC) to determine a data fetching time, a memory address of data to be fetched, and a number of data blocks to be fetched.

6. The cache control device of claim 1 , wherein in a case in which the prefetch instruction in the program code comprises, as an input parameter, an offset value between a base memory address and a memory address of data to be fetched, the prefetch processor obtains the memory address of the data to be fetched by adding the offset value to the base memory address.

7. The cache control device of claim 6 , wherein the prefetch processor obtains the base memory address by monitoring a data bus.

8. The cache control device of claim 1 , wherein the prefetch instruction in the program code is executed using an empty slot of a very long instruction word (VLIW).

9. A prefetch method comprising:
analyzing a memory access pattern of program code;
generating a prefetch instruction by encoding the analyzed memory access pattern;
inserting the generated prefetch instruction into the program code;
prefetching data into a cache, in response to an execution of the prefetch instruction that is inserted into the program code; and
changing into a single array structure a plurality of data to be simultaneously used such that the plurality of data are all prefetched together into the cache.

10. The prefetch method of claim 9 , wherein the generating of the prefetch instruction comprises generating a prefetch table storing input parameters of the prefetch instruction, and the prefetching of the data comprises executing the prefetch instruction inserted into the program code based on the input parameters.

11. The prefetch method of claim 9 , wherein the prefetching of the data into the cache comprises prefetching the data according to a regular pattern in response to the execution of the prefetch instruction inserted into the program code.

12. The prefetch method of claim 9 , wherein the analyzing of the memory access pattern comprises compiling the program code into binary code and analyzing the memory access pattern by profiling the binary code.

13. The prefetch method of claim 9 , wherein, in a case in which the prefetch instruction in the program code comprises, as an input parameter, an offset value between a base memory address and a memory address of data to be fetched, the prefetching of the data into the cache comprises determining the memory address of the data to be prefetched by adding the offset value to the base memory address.

14. The prefetch method of claim 13 , wherein the prefetching of the data into the cache comprises obtaining the base memory address by monitoring a data bus.

15. The prefetch method of claim 9 , wherein the prefetching of the data into the cache comprises determining a time at which to prefetch the data by monitoring a program counter.

16. A cache control device comprising:
a code conversion processor configured to generate a prefetch instruction by encoding an analyzed memory access pattern of program code, and to insert the generated prefetch instruction into the program code;
a prefetch processor configured to prefetch data into a cache, in response to an execution of the prefetch instruction inserted into the program code; and
an optimization processor configured to change a plurality of data to be simultaneously used together into a single array structure, such that the plurality of data are all prefetched together into the cache.

17. The cache control device of claim 16 , further comprising:
a prefetch table configured to store input parameters of the prefetch instruction,
wherein the prefetch processor executes the prefetch instruction inserted into the program code, based on the input parameters.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kim Jun Kyoung
• Yoo Dong Hoon
• Kim Jeong Wook
• Ryu Soo Jung

Classifications

• G06F12/0862 Primary

  with prefetch · CPC title

• G06F2212/452

  Instruction code · CPC title

• G06F9/383

  Operand prefetching (cache prefetching G06F12/0862) · CPC title

• G06F2212/6026

  Prefetching based on access pattern detection, e.g. stride based prefetch · CPC title

• G06F8/4442

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