Re: JIT compiling with LLVM v9.1

On 02/02/2018 10:48 AM, Pierre Ducroquet wrote:
> I have successfully built the JIT branch against LLVM 4.0.1 on Debian testing.
> This is not enough for Debian stable (LLVM 3.9 is the latest available there),
> but it's a first step.
> I've split the patch in four files. The first three fix the build issues, the
> last one fixes a runtime issue.
> I think they are small enough to not be a burden for you in your developments.
> But if you don't want to carry these ifdefs right now, I maintain them in a
> branch on a personal git and rebase as frequently as I can.

I tested these patches and while the code built for me and passed the 
test suite on Debian testing I have a weird bug where the very first 
query fails to JIT while the rest work as they should. I think I need to 
dig into LLVM's codebase to see what it is, but can you reproduce this 
bug at your machine?

Code to reproduce:

SET jit_expressions = true;
SET jit_above_cost = 0;
SELECT 1;
SELECT 1;

Output:

postgres=# SELECT 1;
ERROR:  failed to jit module
postgres=# SELECT 1;
  ?column?
----------
         1
(1 row)

Config:

Version: You patches applied on top of 
302b7a284d30fb0e00eb5f0163aa933d4d9bea10
OS: Debian testing
llvm/clang: 4.0.1-8

Andreas