dune-common does not build with clang 7 and Vc

Vc does some intrinsics call that clang is decidedly unhappy with:

https://gitlab.dune-project.org/core/dune-common/-/jobs/71080

I'll disable Vc for clang 7 in the CI for the time being.

@joe Could you maybe take a look at this?

assigned to @joe

I'd like to get Vc out of the core and into it's own module. This kind of stuff is inherently compiler-specific, so making it a separate module would decouple the requirements somewhat. Making it a separate module is easily possible with the new simd infrastructure, it's already been done for vectorclass. The problem is that it isn't as easy with the old SIMD infrastructure, which has been deprecated only after 2.6, so there are transition questions.

I just noticed that Vc made it into Parallelism 2 TS N4773, though significantly transformed.

One issue is that Vc in the image is now version 1.3.3, while previously we only tested 1.2 (I think)

I'm using the following setup to figure out which Vc versions work:

• Dockerfile
• clang-7-libcpp-17
• dune-common check out at master@673679d0e9a73864e908cfd0f92f65c642fa1a89
• Vc with a recent enough checkout to contain the tag checked out in Dockerfile

Tests suggest that this is fixed in Vc 1.4.1. 1.4.0 still gives the same error.

mentioned in commit 3bd5a4ca

mentioned in merge request !591 (merged)

closed via merge request !591 (merged)

mentioned in commit ef835c4b

mentioned in merge request docker/ci!62 (merged)

mentioned in issue dune-istl#93 (closed)

mentioned in commit docker/ci@5cf2d3b3