This patch adds a large number of missing includes in the libc++ headers
and the test suite. Those were found as part of the effort to move
towards a mostly monolithic top-level std module.
Picolibc is a C Standard Library that is commonly used in embedded
environments. This patch adds initial support for this configuration
along with pre-commit CI. As of this patch, the test suite only builds
the tests and nothing is run. A follow-up patch will make the test suite
actually run the tests.
Differential Revision: https://reviews.llvm.org/D154246
Testing all the SIMD widths exhaustively is nice in theory, however in
practice it leads to extremely slow tests. Given that
1. our testing resources are finite and actually pretty costly
2. we have thousands of other tests we also need to run
3. the value of executing these SIMD tests for absolutely all supported
SIMD widths is fairly small compared to cherry-picking a few relevant
widths
I think it makes a lot of sense to reduce the exhaustiveness of these
tests. I'm getting a ~4x speedup for the worst offender
(reference_assignment.pass.cpp) after this patch.
I'd also like to make this a reminder to anyone seeing this PR that
tests impact everyone's productivity. Slow unit tests contribute to
making the CI slower as a whole, and that has a direct impact on
everyone's ability to iterate quickly during PRs. Even though we have a
pretty robust CI setup in place, we should remember that it doesn't come
for free and should strive to keep our tests at a good bang for the buck
ratio.
[libcxx] <experimental/simd> Added internal storage type for class simd/simd_mask
[libcxx] <experimental/simd> Added all constructors of class simd/simd_mask and related tests
[libcxx] <experimental/simd> Added basic simd reference implementation, subscript operators of class simd/simd_mask and related tests
Reviewed By: #libc, philnik
Differential Revision: https://reviews.llvm.org/D144364
