Out-of-Order Execution Pipeline Interrupt Masking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Modern processors face challenges in efficiently executing complex instructions such as floating-point operations and load/store operations, which require more resources and time, impacting overall throughput, especially in multiprocessor systems where instructions need to be executed in parallel without interruptions.
Innovation Solution
The implementation of an out-of-order execution pipeline with advanced instruction handling and exception management mechanisms, including register renaming and interrupt masking techniques, allows for the efficient execution of complex instructions by optimizing resource allocation and handling interrupts effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If out-of-order execution is employed to execute instructions in parallel, then processor throughput is improved, but interrupt handling complexity increases
Solution Approach 1:
The patent segments the interrupt handling process into distinct phases: interrupt masking during out-of-order execution, identification of the specific instruction causing the interrupt, and selective replay of only the necessary instructions. This segmentation allows the system to manage interrupt complexity while maintaining high throughput by not requiring full sequential replay of all instructions.
Solution Approach 2:
The patent implements preliminary interrupt masking before out-of-order execution proceeds, preventing interrupts from disrupting the execution pipeline. The system prepares mask registers and tracking mechanisms in advance, allowing interrupts to be safely handled after execution completes or at designated checkpoint, rather than requiring immediate interruption of the out-of-order pipeline.
2Adaptability or versatility
If complex instructions such as floating-point operations are executed, then computational capability is improved, but execution time and resource consumption increase
Solution Approach 1:
The patent maintains continuity of useful action by allowing out-of-order execution to proceed with complex instructions without interruption. The system continues executing independent instructions while complex operations are being processed, and only pauses to handle interrupts when necessary. This ensures that computational resources remain actively utilized rather than idle during complex instruction execution.
Solution Approach 2:
The patent implements dynamic instruction scheduling that adapts to the complexity of instructions being executed. The out-of-order execution engine dynamically adjusts which instructions are issued to execution units based on resource availability, instruction complexity, and interrupt status. Complex floating-point operations are scheduled when execution units are available, maximizing computational throughput while minimizing idle time.
3Productivity
If interrupts are masked to allow continuous execution, then processor efficiency is improved, but interrupt response time is delayed
Solution Approach 1:
The patent implements feedback mechanisms that track which instructions have been executed and their dependency relationships. When an interrupt occurs, the system uses this feedback information to determine the minimal set of instructions that need to be replayed to maintain correctness. This feedback-driven approach allows the system to balance efficiency and response time by replaying only necessary instructions rather than all executed instructions.
Solution Approach 2:
The patent changes the parameter of interrupt masking from a binary state (masked or unmasked) to a dynamic state where masking is applied selectively to specific instruction windows. The system adjusts the masking duration and scope based on the type of interrupt, the current execution state, and the criticality of the interrupt, allowing optimized balance between efficiency and response time for different scenarios.
Data Source
AI summary
A processor includes a processor trace logical unit to produce branch execution records from execution of instructions. The processor further includes logic to determine that a condition has occurred on the processor during execution of the instructions. The condition is to include an asynchronous event or a return from a software handler for an asynchronous event. The processor further includes logic to determine whether event tracing is enabled for the processor. The processor also includes logic to generate a control flow event (CFE) packet. The CFE packet is to indicate a type of the condition. The processor further includes logic to generate an indicator of an instruction address that generated the condition.