Statically speculative compilation and execution

• US 7,493,607 B2
• Filed: 07/09/2002
• Issued: 02/17/2009
• Est. Priority Date: 07/09/2002
• Status: Expired due to Term

• Current Assignee: III Holdings 2, LLC (Intellectual Ventures LLC), MORITZ, CSABA ANDRAS
• Original Assignee: BlueRISC Inc.
• Inventors: Moritz, Csaba Andras
• Primary Examiner(s): Zhen, Wei
• Assistant Examiner(s): Nahar, Qamrun
• Application Number:
  US10/191,646
• Publication Number:
  US 20040010782A1
• Time in Patent Office: 2,415 Days
• Field of Search: 717151-155, 717/158, 712/239, 711/129
• US Class Current: 717/151
• CPC Class Codes: G06F 1/32 Means for saving power
• CPC Class Codes: G06F 8/44 Encoding
• CPC Class Codes: G06F 8/4432 Reducing the energy consumption
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A system, for use with a compiler architecture framework, includes performing a statically speculative compilation process to extract and use speculative static information, encoding the speculative static information in an instruction set architecture of a processor, and executing a compiled computer program using the speculative static information, wherein executing supports static speculation driven mechanisms and controls.

Claims

1. A method for use with a compiler architecture framework, the method comprising:

performing a statically speculative compilation process on a computer program to extract speculative static information;

encoding the speculative static information in an instruction set architecture of a processor in order to affect power consumption of a processor resource during use of the processor resource, the speculative static information identifying an access path of the processor resource; and

executing a compiled computer program in the processor using the speculative static information encoded in the instruction set architecture, wherein executing comprises using the access path at run time to reduce resource power consumption for an individual use of the processor resource.

2. The method of claim 1, wherein affecting power consumption comprises controlling the processor resource using the speculative static information encoded in the instruction set architecture.

3. The method of claim 1, wherein affecting power consumption comprises operating processor-related mechanisms using the speculative static information encoded in the instruction set architecture.

4. The method of claim 1, wherein the speculative static information comprises information about one or more of processor resource demands and information that contributes to determining processor resource demands.

5. The method of claim 1, wherein executing includes executing the compiled computer program along static, static-dynamic, and dynamic execution paths.

6. The method of claim 1, wherein the instruction set architecture comprises at least one of modified and additional instructions configured to propagate information through code and to store information.

7. The method of claim 1, wherein the statically speculative compilation process exposes speculative static information to run time layers;

and

wherein microarchitecture which performs the executing provides a mechanism to recover from static misprediction.

8. The method of claim 1, wherein the speculative static information comprises a single command encoded in the instruction set architecture, the single command for implementing plural techniques to reduce processor power consumption.

9. The method of claim 1, wherein the speculative static information comprises predictable static information and additional static information that is speculated based on the predictable static information.

10. The method of claim 1, wherein executing is performed by microarchitecture that contains an extension, the extension supporting correctness of execution for performing the statically speculative compilation process.

11. The method of claim 10, wherein the extension is comprised of at least one of hardware and software.

12. The method of claim 1, wherein the statically speculative compilation process performs static speculation, the static speculation determining information about execution of the compiled computer program, the static speculation being controlled on application-specific and adaptive bases and being managed with compile-time flags.

13. The method of claim 8, wherein the statically speculative compilation process determines processor performance and energy tradeoffs during compile-time and at least one of the plural techniques comprises using the energy tradeoffs during execution.

14. The method of claim 1, wherein the statically speculative compilation process performs design objective customization without changing microarchitecture used to perform the executing.

15. The method of claim 1, wherein more information about processor resource usage is exposed with speculative static compilation than with predictable static information.

16. The method of claim 1, wherein microarchitecture performs the executing, the microarchitecture using the speculative static information and dynamic information during executing.

17. The method of claim 1, wherein the method is used in a silicon-based electronics system.

18. The method of claim 1, wherein the method is used in a nano-electronics based electronic system.

19. A processing device comprising:

machine storage for storing a compiler that is configured to compile a computer program, the compiler being configured to extract speculative static information about the computer program during compilation, to use the speculative static information in a tagless cache system in order to affect power consumption of a cache during use of the cache, the speculative static information being usable to predict access paths for cache accesses at run time; and

the tagless cache system that is accessible based on the extracted speculative static information, wherein individual cache accesses predicted using the speculative static information contribute to reduction in cache power and processing device energy consumption.

20. The processing device of claim 19, wherein the speculative static information is used to register promote cache pointer information to predict cache accesses.

21. The processing device of claim 19, wherein the speculative static information is used to select cache pointers at run time to predict cache accesses.

22. The processing device of claim 19, further comprising at least one of:

a scratchpad-memory based cache mechanism; and

an associative cache.

23. The processing device of claim 22, wherein the compiler is configured to select which of plural cache accesses are mapped to which cache mechanisms based on the speculative static information.

24. The processing device of claim 22, wherein frequently used data with a low memory footprint is mapped to the scratchpad-memory based cache mechanism.

25. The processing device of claim 19, wherein associativity and block size in the tagless cache system are logical and programmable.

26. The processing device of claim 25, wherein the compiler is configured to determine block sizes and associativity of a cache based on an analysis of the computer program.

27. The processing device of claim 19, further comprising a memory area for storing a cache pointer.

28. The processing device of claim 19, further comprising a Cache TLB (Translation Look-ahead Buffer) for capturing statically mispredicted cache pointers and other types of cache pointers.

29. The processing device of claim 28, wherein the Cache TLB comprises eight entries.

30. The processing device of claim 19, further comprising a microarchitecture for use in accessing the tagless cache system, the microarchitecture being configured to access the tagless cache system using at least one of static, static-dynamic, and dynamic cache access paths.