Re: Requiring LLVM 14+ in PostgreSQL 18

Thomas Munro <thomas.munro@gmail.com>

From: Thomas Munro <thomas.munro@gmail.com>

To: pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2024-04-23T23:43:12Z

Lists: pgsql-hackers

Attachments

v2-0001-jit-Require-at-least-LLVM-14-if-enabled.patch (application/octet-stream) patch v2-0001
v2-0002-jit-Use-opaque-pointers-in-all-supported-LLVM-ver.patch (application/octet-stream) patch v2-0002

Rebased over ca89db5f.

I looked into whether we could drop the "old pass manager" code
too[1].  Almost, but nope, even the C++ API lacks a way to set the
inline threshold before LLVM 16, so that would cause a regression.
Although we just hard-code the threshold to 512 with a comment that
sounds like it's pretty arbitrary, a change to the default (225?)
would be unjustifiable just for code cleanup.  Oh well.

[1] https://github.com/macdice/postgres/commit/0d40abdf1feb75210c3a3d2a35e3d6146185974c

Commits

doc: remove llvm-config search from configure documentation
- 0c7ec3b3a03b 17.0 landed
- 4baff5013277 18.0 landed
jit: Remove {llvm-config,clang}-N configure probes.
- 4dd29b683334 17.0 landed