llvm-project

0c6784c9 - [MemDep] Optimize SortNonLocalDepInfoCache sorting strategy for large caches with few unsorted entries (#143107)

[MemDep] Optimize SortNonLocalDepInfoCache sorting strategy for large caches with few unsorted entries (#143107) During compilation of large files with many branches, I observed that the function `SortNonLocalDepInfoCache` in `MemoryDependenceAnalysis` becomes a significant performance bottleneck. This is because `Cache.size()` can be very large (around 20,000), but only a small number of entries (approximately 5 to 8) actually need sorting. The original implementation performs a full sort in all cases, which is inefficient. This patch introduces a lightweight heuristic to quickly estimate the number of unsorted entries and choose a more efficient sorting method accordingly. As a result, the GVN pass runtime on a large file is reduced from approximately 26.3 minutes to 16.5 minutes.