Reimplement NormalizeArrayLen based on SsaLocals #107172
Conversation
|
r? @nagisa (rustbot has picked a reviewer for you, use r? to override) |
rustbot
added
S-waiting-on-review
|
Some changes occurred to MIR optimizations cc @rust-lang/wg-mir-opt |
|
|
||
| pub struct NormalizeArrayLen; | ||
|
|
||
| impl<'tcx> MirPass<'tcx> for NormalizeArrayLen { | ||
| fn is_enabled(&self, sess: &rustc_session::Session) -> bool { | ||
| // See #105929 | ||
| sess.mir_opt_level() >= 4 && sess.opts.unstable_opts.unsound_mir_opts | ||
| sess.mir_opt_level() >= 3 |
There was a problem hiding this comment.
Shouldn’t the comment above be removed at this point?
| && let Some(cast_ty) = cast_ty.builtin_deref(true) | ||
| && let ty::Slice(..) = cast_ty.ty.kind() |
There was a problem hiding this comment.
(This is just me trying to understand code rather than suggesting any particular change to be made – you can largely ignore this.) Is this check necessary at all? I guess it is a nice defense-in-depth measure, but what other things an unsizing cast could be to? A dynamic object?
There was a problem hiding this comment.
Yes, Unsize has to be interpreted based on both input and output types. We only want &[T; _] -> &[T]. The other possible cases are &T -> &dyn Trait, &dyn Trait1 -> &dyn Trait2, Struct<[T; _]> -> Struct<[T]>.
|
☔ The latest upstream changes (presumably #107309) made this pull request unmergeable. Please resolve the merge conflicts. |
cjgillot
added
S-waiting-on-author
|
@bors r=nagisa |
bors
added
S-waiting-on-bors
…iaskrgr Rollup of 7 pull requests Successful merges: - rust-lang#107125 (Add and use expect methods to hir.) - rust-lang#107172 (Reimplement NormalizeArrayLen based on SsaLocals) - rust-lang#107177 (Keep all theme-updating logic together) - rust-lang#107424 (Make Vec::clone_from and slice::clone_into share the same code) - rust-lang#107455 (use a more descriptive name) - rust-lang#107465 (`has_allow_dead_code_or_lang_attr` micro refactor) - rust-lang#107469 (Change turbofish context link to an archive link) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup
Based on #106908
Fixes #105929
Only the last commit "Reimplement NormalizeArrayLen" is relevant.