> On Aug 22, 2018, at 7:13 PM, Andres Freund <andres@anarazel.de> wrote:
[snip]
> For the archives sake: This likely largely is the consequence of
> building with LLVM's expensive assertions enabled, as confirmed by
> Jonathan over IM.
I recompiled with the release version of LLVM. jit=on was still slower,
but the discrepancy was not as bad as the previously reported result:
jit = off
Planning Time: 0.938 ms
Execution Time: 935.599 ms
jit = on
Planning Time: 0.951 ms
JIT:
Functions: 184
Generation Time: 17.605 ms
Inlining: true
Inlining Time: 20.522 ms
Optimization: true
Optimization Time: 1001.034 ms
Emission Time: 665.319 ms
Execution Time: 2491.560 ms
However, it was still 2x+ slower, so still +1ing for open items.
I compiled with whatever switches LLVM that comes with Ubuntu 18.04 is built with, and without debugging or assertions.
With 11b3 as of 825f10fbda7a5d8a48d187b8193160e5e44e4011 I'm repeatedly getting these results with jit=on, after 10 runs:
Planning Time: 0.266 ms
JIT:
Functions: 686
Generation Time: 71.895 ms
Inlining: false
Inlining Time: 0.000 ms
Optimization: false
Optimization Time: 39.906 ms
Emission Time: 589.944 ms
Execution Time: 2198.928 ms
Turning jit=off gives this:
Planning Time: 0.180 ms
Execution Time: 938.451 ms
I can provide dataset offlist if anyone wants to look into this.
