Re: GCC 8.3.0 vs. 9.0.1
Peter Geoghegan <[email protected]>
| Newsgroups | gmane.comp.db.postgresql.performance |
|---|---|
| Message-ID | <CAH2-WzmvCYeQUVgaoeQBxKpBoGU8v4vbNPObFeydBjNcW2SQNA@mail.gmail.com> |
On Tue, May 7, 2019 at 10:06 AM Tom Lane <[email protected]> wrote: > Given the described test setup, I'd put basically no stock in these > numbers. It's unlikely that this test case's performance is CPU-bound > per se; more likely, I/O and lock contention are dominant factors. > So I'm afraid whatever they're measuring is a more-or-less chance > effect rather than a real system-wide code improvement. Or a compiler bug. Link-time optimizations give the compiler a view of the program as a whole, not just a single TU at a time. This enables it to perform additional aggressive optimization. -- Peter Geoghegan