Adaptive Microprocessor Instruction Grouping for Branch Penalty Reduction
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Solution Overview
Problem
Current microprocessor systems face performance bottlenecks due to branch instruction penalties, cache miss rates, and instruction access time issues, which are not adequately addressed by existing technologies that rely on branch prediction and dynamic binary translation.
Innovation Solution
The system employs an adaptive microprocessor that groups and trims branch instructions with non-branch instructions into compact, ciphered instructions, allowing for parallel execution and reducing the number of branch instructions, thereby alleviating branch penalties and optimizing cache memory usage without the need for additional hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If branch prediction hardware is used to handle branch instructions, then the processing speed of branch instructions is improved, but the device complexity and energy consumption increase
Solution Approach 1:
The patent extracts and removes branch instructions from the instruction stream before execution. By identifying and eliminating branch instructions during compilation or code generation, the system avoids the need for complex branch prediction hardware while maintaining processing speed. The extracted branch logic is replaced with equivalent unconditional control flow mechanisms.
Solution Approach 2:
The patent performs branch trimming and instruction grouping as preliminary actions during compilation or code generation, before the program is executed. By preprocessing the code to remove branches and group instructions, the system eliminates the need for runtime branch prediction, reducing hardware complexity while maintaining execution speed.
2Reliability
If traditional instruction formatting is used, then software compatibility is maintained, but the instruction memory size and access time increase
Solution Approach 1:
The patent merges multiple traditional instructions into single grouped instructions. By combining sequential non-branch instructions into compact grouped instruction formats, the system reduces the total number of instructions that need to be stored and fetched from memory, thereby reducing instruction memory size and access time while maintaining functional equivalence.
Solution Approach 2:
The patent changes the format parameters of instructions by introducing compact grouped instruction formats. These new formats encode multiple operations in fewer bits and fewer instruction slots, reducing memory requirements and access time while preserving the original program's functionality through systematic translation.
3Productivity
If branch instructions are eliminated through trimming, then branch misprediction penalties are reduced, but the software code structure changes
Solution Approach 1:
The patent performs branch trimming as a preliminary code transformation step during compilation or code generation. By eliminating branches beforehand and replacing them with equivalent control flow constructs, the system improves computing throughput by removing branch misprediction penalties while systematically adapting the code structure to the new branchless format.
Solution Approach 2:
The patent changes the structural parameters of the software code by transforming branched control flow into equivalent branchless constructs. This involves modifying the code organization and instruction sequences while preserving the program's logical behavior, enabling improved throughput without losing adaptability.
4Quantity of substance
If instruction grouping is performed to reduce memory usage, then cache memory size is reduced, but the decoding complexity of instructions increases
Solution Approach 1:
The patent segments the decoding process into distinct stages: identification of grouped instructions, extraction of constituent operations, and execution of individual operations. By dividing the decoding task into manageable segments, the system reduces cache memory size through grouping while managing decoding complexity through systematic segmentation of the decoding workflow.
Solution Approach 2:
The patent introduces intermediary data structures and translation layers that bridge the compact grouped instruction format and the execution units. These intermediaries handle the complexity of decoding grouped instructions, allowing the system to reduce cache memory size while isolating decoding complexity in dedicated translation hardware or software layers.
Data Source
AI summary
Multiple instructions including branch instructions are grouped into a condensed variable length instruction. A trimmed and grouped branch instruction branches to one of the instructions in the same group. Therefore, a grouped instruction including branch(es) inherently executes correct branch behaviors without deploying any branch prediction schemes. In addition, a grouped instruction in a condensed form delivers multiple operations to execute without fetching all of the instructions grouped separately from the instruction memory via its caches while conserving instruction memory and/or cache as well as decreasing the number of bit switching on the bus. Software developers can make their own compatible, compact and ciphered instruction sets after grouping existing instructions in their software compiled with existing software compilers and the associated microprocessors.