move of packed fields might or might not occur when they actually are sufficiently aligned #63374
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… sufficiently aligned
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r? @cramertj (rust_highfive has picked a reviewer for you, use r? to override) |
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Is there a reason we don't do something similar for |
Not that I know if. Honestly I was surprised we do any magic at all even for 1-aligned types, but it makes sense of course. |
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@bors r+ I guess? |
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📌 Commit e82b053 has been approved by |
Whatever that means?^^ |
RalfJung
commented
Aug 8, 2019
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Just removed that weird lead-in to the new sentence. @bors r=cramertj |
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📌 Commit fa58c27 has been approved by |
Just that I think this is a good clarifying remark to have, but the actual behavior is somewhat strange. |
Centril
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move of packed fields might or might not occur when they actually are sufficiently aligned See taiki-e/pin-project#34, where it was pointed out that we actually don't move fields of 1-aligned types when dropping a packed struct -- but e.g. in a `packed(2)` struct, we don't do something similar for 2-aligned types. The code for that is [here](https://github.com/rust-lang/rust/blob/db7c773a6be2f050d1d1504763819ea3916f5428/src/librustc_mir/util/alignment.rs#L7).
Centril
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move of packed fields might or might not occur when they actually are sufficiently aligned See taiki-e/pin-project#34, where it was pointed out that we actually don't move fields of 1-aligned types when dropping a packed struct -- but e.g. in a `packed(2)` struct, we don't do something similar for 2-aligned types. The code for that is [here](https://github.com/rust-lang/rust/blob/db7c773a6be2f050d1d1504763819ea3916f5428/src/librustc_mir/util/alignment.rs#L7).
bors
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Rollup of 6 pull requests Successful merges: - #63162 (Miri tests: use xargo to build separate libstd) - #63289 (Don't recommend `extern crate` syntax) - #63373 (gitignore: add comment explaining policy) - #63374 (move of packed fields might or might not occur when they actually are sufficiently aligned) - #63381 (reduce visibility) - #63387 (Test interaction between `async { ... }` and `?`, `return`, and `break`) Failed merges: r? @ghost
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See taiki-e/pin-project#34, where it was pointed out that we actually don't move fields of 1-aligned types when dropping a packed struct -- but e.g. in a
packed(2)struct, we don't do something similar for 2-aligned types. The code for that is here.