On 30/09/2020 19:04, Zidenberg, Tsahi wrote:
Ubuntu 20.04 even turned it off by default for gcc-10, which seems
like a compatibility step with the main gcc-9 compiler.
Ok, I definitely don't want to override that decision.
I'm marking this as Rejected in the commitfest. But thanks for the
benchmarking, that is valuable information nevertheless.
Could additional data change your mind?
I doubt it. IMO we shouldn't second-guess decisions made by compiler and
distribution vendors, and more performance data won't change that
principle. For comparison, we also don't set -O or -funroll-loops or any
other flags to enable/disable specific optimizations. (Except for a few
specific source files, like checksum.c, but those are exceptions the rule.)
If some other committer thinks differently, I won't object, but I'm not
going to commit this. Maybe you should speak to the distribution vendors
or the folk packaging PostgreSQL for those distributions, instead.
- Heikki
