Runtime Alias Check Grouping for Faster Loop Optimization
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Solution Overview
Problem
Existing compiler optimizations face inefficiencies due to the high number of runtime alias checks required for memory accesses, which hinder performance and prevent effective loop optimizations.
Innovation Solution
Optimizing runtime alias checks by identifying a base pointer and generating code to determine minimum and maximum memory accesses, reducing the number of checks through grouping based on common memory access patterns and applying loop optimizations only when the estimated cost is below a threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If runtime alias checks are inserted for all memory accesses, then correctness of code generation is ensured, but computational performance deteriorates due to high check overhead
Solution Approach 1:
The patent segments memory accesses into groups based on common patterns, identifying base pointers and their associated accesses. By grouping accesses with the same base pointer and access pattern, the system performs alias checks at the group level rather than for each individual access, reducing the total number of checks while maintaining correctness.
Solution Approach 2:
The patent performs preliminary analysis at compile time to identify base pointers, memory access patterns, and grouping opportunities. This preliminary action includes determining which memory accesses can be grouped together and preparing the structure for optimized runtime checking, so that runtime overhead is minimized.
2Productivity
If runtime alias checks are reduced through grouping, then computational performance improves, but measurement precision of alias analysis deteriorates
Solution Approach 1:
The patent applies local quality by performing detailed alias analysis only where necessary - specifically at the boundaries of grouped memory accesses and for base pointers that require disambiguation. Within groups with common access patterns, the precision requirements are relaxed since the grouping itself provides sufficient information for correct optimization.
3Productivity
If loop optimizations are applied, then productivity increases, but device complexity increases due to additional optimization logic
Solution Approach 1:
The patent performs preliminary identification and grouping of memory accesses by base pointer before loop optimization. By pre-organizing the memory access information and determining grouping opportunities in advance, the compiler reduces the complexity of the optimization logic needed during loop transformation, as the grouping structure is already established.
Data Source
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AI summary
Optimizing runtime alias checks includes identifying, by a compiler, a base pointer and a plurality of different memory accesses based on the base pointer in a code loop; generating, by the compiler, a first portion of runtime code to determine a minimum access and a maximum access of the plurality of different memory accesses; and generating, by the compiler, a second portion of runtime code including one or more runtime alias checks for the minimum access and one or more runtime alias checks for the maximum access.