mnatsuhara added a comment. After following up with the team responsible for `__builtin_zero_non_value_bits` on MSVC, I have some more information to offer in conjunction with @BillyONeal's report:
- For unions, we always assume that it has unique object representations and thus does not have any padding bytes. This allows `__builtin_zero_non_value_bits` to be used with types with union members, not always accurately but never destructively. (If the union has padding bytes, we don't know which member is active so we don't know exactly where the padding bytes are. To return padding bytes assuming any member risks changing the value.) - Our implementation does appear to include tail padding and this would include any such padding that is due to alignment requirements, etc. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D87974/new/ https://reviews.llvm.org/D87974 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
