I suppose that these 2 tests were always failing on 32-bit.
The old builder history doesn't go very far, but it shows these tests always failing: http://lab.llvm.org:8011/#/builders/34?numbuilds=300.
Not sure if it was intended or not, but it seems that trivial_abi is only tested on arm64-apple-ios11 triple.
Cf. D41039.

FYI, https://bugs.llvm.org/show_bug.cgi?id=48939.
I think these two failing tests should be disabled on 32-bit x86.
I'm pretty sure for weak_ptr_ret.pass.cpp, cf.:

#ifndef __arm__
  // On ARM32, structs larger than 4 bytes cannot be returned in registers.
  // Thus, weak_ptr will be passed indrectly even if it is trivial.
  assert((void*)&ret != local_addr);
#endif

Not sure for unique_ptr_ret.pass.cpp though.

curdeius mentioned this in D102359: [libc++] [test] Fix a few tests for 32-bit x86.May 14 2021, 12:12 AM

Rebase onto main - I think the underlying issues should have been fixed now.

Rebase onto main with the underlying issue fixed for real.

Harbormaster completed remote builds in B106934: Diff 348825.May 31 2021, 6:08 PM

Poke CI.

Harbormaster completed remote builds in B107124: Diff 349091.Jun 1 2021, 6:03 PM

ldionne accepted this revision as: Restricted Project.Jun 1 2021, 7:07 PM

This revision was not accepted when it landed; it landed in state Needs Review.Jun 1 2021, 7:07 PM

Closed by commit rGae4dad2b731e: [libc++] Add a CI job to test libc++ when building for 32 bit (authored by ldionne). · Explain Why

This revision was automatically updated to reflect the committed changes.

ldionne added a commit: rGae4dad2b731e: [libc++] Add a CI job to test libc++ when building for 32 bit.