Conversion Look Aside Buffer for Guest Instruction Translation
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Solution Overview
Problem
Current code transformation and translation processes in digital computer systems, such as just-in-time compilation and interpretation, incur significant overhead, leading to performance penalties and latency issues due to processor cycles and memory management, especially during the conversion of guest instructions to native instructions.
Innovation Solution
A hardware-based acceleration method that converts guest instruction blocks into native conversion blocks, utilizing a conversion look aside buffer to cache mappings and store frequently accessed native instructions, allowing for rapid execution and reducing the need for repeated memory access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If just-in-time compilation is used to translate guest instructions to native instructions, then code execution performance is improved, but processor overhead and latency increase significantly
Solution Approach 1:
The patent pre-generates native instruction conversion blocks for common guest instruction sequences during system initialization or idle periods, storing them in a dedicated cache. When guest instructions need to be executed, the system checks the cache for pre-generated conversion blocks, avoiding real-time translation overhead and reducing latency significantly.
Solution Approach 2:
The patent implements a dynamic caching system that adapts to workload patterns by selectively caching conversion blocks based on frequency of use. The system dynamically manages the conversion block cache, evicting less frequently used blocks and retaining hot paths, thereby optimizing the balance between cache utilization and translation performance.
2Loss of time
If interpretation mode is used to decode instructions, then processor overhead is reduced compared to JIT compilation, but the transformed code produces lower execution performance
Solution Approach 1:
The patent segments the instruction translation process into two distinct phases: a low-overhead interpretation phase that generates conversion blocks, and a high-performance execution phase that uses pre-generated conversion blocks from cache. This segmentation allows the system to benefit from both interpretation's low overhead and JIT compilation's high performance for frequently executed code.
Solution Approach 2:
The patent creates copy-optimized versions of guest instruction blocks by generating native instruction conversion blocks that are cached for rapid retrieval. Instead of repeatedly interpreting the same guest instructions, the system copies the translated native code into the conversion block cache, enabling fast execution without repeated translation overhead.
3Productivity
If converted native instruction blocks are stored in system memory, then code can be executed, but memory mapping and allocation management overhead increases latency
Solution Approach 1:
The patent introduces a dedicated conversion block cache as an intermediary structure between system memory and the execution pipeline. This cache is optimized for storing conversion blocks with fixed-size entries and direct indexing, eliminating the need for complex memory mapping and allocation management while providing fast access to translated code.
Solution Approach 2:
The patent changes the organizational parameters of the storage structure by implementing a fixed-size, directly-addressable conversion block cache rather than using dynamic memory allocation. Each cache entry has a predetermined size and position, allowing O(1) access time and eliminating memory management overhead associated with dynamic allocation and mapping.
4Loss of time
If guest instructions are processed individually through interpretation, then translation overhead per instruction is minimized, but repeated invocation creates significant cumulative overhead
Solution Approach 1:
The patent merges multiple individual guest instruction translations into block-level conversion operations. Instead of translating and executing instructions one at a time, the system translates sequences of guest instructions into conversion blocks that are cached and executed as units, reducing the cumulative overhead of repeated interpretation invocations.
Solution Approach 2:
The patent maintains continuous execution flow by caching conversion blocks for frequently executed instruction sequences. Once a conversion block is generated, it remains in the cache for rapid reuse, eliminating the need for repeated interpretation invocations and maintaining continuous, high-speed execution without interruptions for translation overhead.
Data Source
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AI summary
A method for translating instructions for a processor. The method includes accessing a plurality of guest instructions that comprise multiple guest branch instructions, and assembling the plurality of guest instructions into a guest instruction block. The guest instruction block is converted into a corresponding native conversion block. The native conversion block is stored into a native cache. A mapping of the guest instruction block to corresponding native conversion block is stored in a conversion look aside buffer. Upon a subsequent request for a guest instruction, the conversion look aside buffer is indexed to determine whether a hit occurred, wherein the mapping indicates whether the guest instruction has a corresponding converted native instruction in the native cache. The converted native instruction is forwarded for execution in response to the hit.