[PATCH] D35056: GCC ABI incompatibility when passing object with trivial copy ctor, trivial dtor, and non-trivial move ctor

[Richard Smith - zygoloid via Phabricator via cfe-commits]

rsmith added a comment.

In https://reviews.llvm.org/D35056#834705, @rnk wrote:

> In https://reviews.llvm.org/D35056#834689, @rsmith wrote:
>
> > I also removed some incorrect assumptions from the Win64 ABI code; this changed the behavior of one testcase from uncopyable-args.cpp (`implicitly_deleted_copy_ctor::A` is now passed indirect).
>
>
> That's probably not correct, let me take a look... I remember breaking the rules for small types here.


I forgot to say: the new behavior matches MSVC. (The immediate bug was that we didn't consider the possibility that a user-declared copy assignment operator could cause the implicit copy constructor to be deleted, but there may have been other bugs also caused by this part of CodeGen attempting to work out deletedness for itself rather than asking.)


Repository:
  rL LLVM

https://reviews.llvm.org/D35056