Understanding Correctness Failures in Compiler Optimization

Compiler optimizations improve program performance but may break program correctness when transformations fail to preserve source level semantics. This extended abstract examines optimization introduced correctness failures in GCC through bugs reported by existing C compiler testing studies. We collect bug report metadata, recover available proof of concept programs, and manually validate each program before building the testing corpus. The current dataset contains 226 analyzed GCC bugs, including 159 bugs that are directly or partially related to optimization components. Our preliminary results show that tree optimization is the primary component involved in these failures, while wrong code is the most common failure type. These findings provide an empirical basis for an optimization oriented testing framework and a reusable test suite for improving compiler optimization correctness and reliability.