This reverts commit b0bc93da92.
Changes: `s/_WIN32/_WIN64/g` in clang/test/SemaCXX/attr-trivial-abi.cpp.
The calling convention is specific to 64-bit windows. It's even in the name: `CCK_MicrosoftWin64`.
After this, the test passes with both `-triple i686-pc-win32` and `-triple x86_64-pc-win32`. Phew!
Reviewed By: gribozavr2
Differential Revision: https://reviews.llvm.org/D123059
This reverts commit 56d46b36fc.
The LIT test SemaCXX/attr-trivial-abi.cpp is failing with 32bit build on
Windows. All the lines with the ifdef WIN32 are asserting but they are
not expected to. It looks like the LIT test was not tested on a 32bit
build of the compiler.
This reverts commit 852afed5e0.
Changes since D114732:
On PS4, we reverse the expectation that classes whose constructor is deleted are not trivially relocatable. Because, at the moment, only classes which are passed in registers are trivially relocatable, and PS4 allows passing in registers if the copy constructor is deleted, the original assertions were broken on PS4.
(This is kinda similar to DR1734.)
Reviewed By: gribozavr2
Differential Revision: https://reviews.llvm.org/D119017
This change enables library code to skip paired move-construction and destruction for `trivial_abi` types, as if they were trivially-movable and trivially-destructible. This offers an extension to the performance fix offered by `trivial_abi`: rather than only offering trivial-type-like performance for pass-by-value, it also offers it for library code that moves values but not as arguments.
For example, if we use `memcpy` for trivially relocatable types inside of vector reallocation, and mark `unique_ptr` as `trivial_abi` (via `_LIBCPP_ABI_ENABLE_UNIQUE_PTR_TRIVIAL_ABI` / `_LIBCPP_ABI_UNSTABLE` / etc.), this would speed up `vector<unique_ptr>::push_back` by 40% on my benchmarks. (Though note that in this case, the compiler could have done this anyway, but happens not to due to the inlining horizon.)
If accepted, I intend to follow up with exactly such changes to library code, including and especially `std::vector`, making them use a trivial relocation operation on trivially relocatable types.
**D50119 and P1144:**
This change is very similar to D50119, which was rejected from Clang. (That change was an implementation of P1144, which is not yet part of the C++ standard.)
The intent of this change, rather than trying to pick a winning proposal for trivial relocation operations, is to extend the behavior of `trivial_abi` in a way that could be made compatible with any such proposal. If P1144 or any similar proposal were accepted, then `trivial_abi`, `__is_trivially_relocatable`, and everything else in this change would be redefined in terms of that.
**Safety:**
It's worth pointing out, specifically, that `trivial_abi` already implies trivial relocatability in a narrow sense: a `trivial_abi` type, when passed by value, has its constructor run in one location, and its destructor run in another, after the type has been trivially relocated (through registers).
Trivial relocatability optimizations could change the number of paired constructor/destructor calls, but this seems unlikely to matter for `trivial_abi` types.
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D114732
Devin Jeanpierre