Extraction and traceability of annotations for WCET estimation

Hanbing Li 1
1 ALF - Amdahl's Law is Forever
Inria Rennes – Bretagne Atlantique , IRISA-D3 - ARCHITECTURE
Abstract : Real-time systems have become ubiquitous, and play an important role in our everyday life. For hard real-time systems, computing correct results is not the only requirement. In addition, the worst-case execution times (WCET) are needed, and guarantee that they meet the required timing constraints. For tight WCET estimation, annotations are required. Annotations are usually added at source code level but WCET analysis is performed at binary code level. Compiler optimization is between these two levels and has an effect on the structure of the code and annotations.We propose a transformation framework for each optimization to trace the annotation information from source code level to binary code level. The framework can transform the annotations without loss of flow information. We choose LLVM as the compiler to implement our framework. And we use the Mälardalen, TSVC and gcc-loops benchmarks to demonstrate the impact of our framework on compiler optimizations and annotation transformation. The experimental results show that with our framework, many optimizations can be turned on, and we can still estimate WCET safely. The estimated WCET is better than the original one. We also show that compiler optimizations are beneficial for real-time systems.
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Submitted on : Monday, November 23, 2015 - 6:07:06 PM
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  • HAL Id : tel-01232613, version 1


Hanbing Li. Extraction and traceability of annotations for WCET estimation. Other [cs.OH]. Université Rennes 1, 2015. English. ⟨NNT : 2015REN1S040⟩. ⟨tel-01232613⟩



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