Source-Free Detection and Impact Analysis of Compiler Optimization Problems in Mobile Applications

Mobile apps frequently suffer from frame drops, overheating, and excessive power consumption. While developers optimize algorithms and debug code, a critical bottleneck often goes unnoticed: native libraries compiled with low optimization levels (O0/O1 instead of O2/O3). Because these libraries execute without functional errors, the resulting performance degradation remains hidden in production apps. We present textscOptDetect, a source-free framework that detects compiler optimization problems directly from app binaries. textscOptDetect handles mixed optimization levels through binary disassembly, chunk-level classification, and weighted score aggregation, achieving 93.0% accuracy on controlled datasets and 81.9% on real-world datasets. Applying textscOptDetect to 21,972 native libraries from 830 top-ranked Google Play apps, we find that 30.5% of libraries use low optimization levels, affecting 91.7% of apps. Through case studies on 12 production apps, fixing detected issues reduces CPU instructions by 10-63% (median: 20.5%) for commercial apps and 15-58% (median: 32%) for open-source apps. Performance complaints decrease in 5 of 6 commercial apps, and ratings increase in 5 of 6. Further investigation reveals that widely-used third-party libraries are themselves distributed at low optimization levels, with 49.7% of 1,073 libraries in a major repository exhibiting this problem. These findings show that compiler optimization problems are common, source-free detectable, and practically consequential in mobile app ecosystems.