Halide users reported this here: https://llvm.org/pr46176 I reported the issue to MSVC here: https://developercommunity.visualstudio.com/content/problem/1179643/msvc-copies-overaligned-non-trivially-copyable-par.html This codepath is apparently not covered by LLVM's unit tests, so I added coverage in a unit test. If we want to support this configuration going forward, it means that is in general not safe to pass a SmallVector<T, N> by value if alignof(T) is greater than 4. This doesn't appear to come up often because passing a SmallVector by value is inefficient and not idiomatic: it copies the inline storage. In this case, the SmallVector<LLT,4> is captured by value by a lambda, and the lambda is passed by value into std::function, and that's how we hit the bug. Differential Revision: https://reviews.llvm.org/D87475 NOTE from amaiorano@ : applied this LLVM patch (without the unittest) to SwiftShader. Bug: b/173512119 Change-Id: If036f61386b51f9b4a20427812b4ac92d901244d Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/50469Tested-by: Antonio Maiorano <amaiorano@google.com> Reviewed-by: Nicolas Capens <nicolascapens@google.com>
