[
https://issues.apache.org/jira/browse/ARROW-10321?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17215136#comment-17215136
]
Neal Richardson commented on ARROW-10321:
-----------------------------------------
The X's next to the commits go to Travis builds that failed.
Here's the first, where it builds with {{-DARROW_HAVE_RUNTIME_AVX512}} when it
should not, and it fails:
https://travis-ci.org/github/autobrew/homebrew-core/jobs/736104290#L723
Here's the second, where I set the runtime SIMD level to AVX2 so it didn't have
that flag, yet it still tried to compile util/bpacking_avx512.cc:
https://travis-ci.org/github/autobrew/homebrew-core/jobs/736173702#L725
Then you can see in the discussion on the PR I applied a patch that wrapped
that whole file in {{#if defined(ARROW_HAVE_RUNTIME_AVX512)}}, and the next
build compiled successfully
> [C++] Building AVX512 code when we should not
> ---------------------------------------------
>
> Key: ARROW-10321
> URL: https://issues.apache.org/jira/browse/ARROW-10321
> Project: Apache Arrow
> Issue Type: Bug
> Components: C++
> Reporter: Neal Richardson
> Priority: Major
>
> On https://github.com/autobrew/homebrew-core/pull/31, where we are packaging
> Arrow for an old macOS SDK version, we found what I believe are 2 different
> problems:
> 1. The check for AVX512 support was returning true when in fact the compiler
> did not support it
> 2. Even when we manually set the runtime SIMD level to less-than-AVX512, it
> was still trying to compile one of the AVX512 files, which failed. I added a
> patch that made that file conditional, but there's probably a proper cmake
> way to tell it not to compile that file at all
> cc [~yibo] [~apitrou]
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
