> On 22 May 2024, at 11:27, XChy <xxs_chy@xxxxxxxxxxx> wrote: > > Hi everyone, > I'm a compiler developer working on detecting missed optimization in real-world applications. Recently, we found that LLVM missed a dead store elimination optimization in the PostgreSQL code (https://github.com/postgres/postgres/blob/master/src/backend/utils/adt/ruleutils.c#L3794) in the master branch. How is the memset in select_rtable_names_for_explain a dead-store? Even memset calls could be optimized away from the EXPLAIN codepath I have a feeling it would have to be many in a tight loop for it to be measurable even? -- Daniel Gustafsson