[Users] Vectorization issue

Erik Schnetter schnetter at cct.lsu.edu
Thu Jul 8 09:07:14 CDT 2021

Hee Il

This looks disconcerting. Using vectorization or not should only
affect things at the round-off level (the same way parallelization

The vectorization settings you show look good.

I'd like to dig deeper.

- Is your source code public, or would you be willing to share it with
a few developers?
- Is your parameter file public, or would you be willing to share it
with a few developers?
- The first thing to do is probably to look at other, more fundamental
variables (e.g. metric components) in 3d and see where they begin to
differ. The hope is that they would begin to differ early during the
run. Do you have such 3d output at the same time from both
simulations? Or do you have 1d output e.g. along the x axis for some


On Thu, Jul 8, 2021 at 9:01 AM Hee Il Kim <heeilkim at gmail.com> wrote:
> Hi all,
> While examining different results from my colleague's, I found the vectorization option could develop misleading results. I seldom use the vectorization option but  in the configuration file but he mixed up with mine and others leaving:
> VECTORISE                = yes
> VECTORISE_INLINE         = yes
> in the config file. I found these are default config options in recent simfactory optionlists. Instead, I used to use AVX but always adding e.g., "-fp-model precise" for value safeness.
> I attached two figures with the vectorization on/off. For the  case of no vectorization, I tested it w/wo AVX and got the identical result.
> Hee Il
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Erik Schnetter <schnetter at cct.lsu.edu>

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