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c03eba2d08
I've tried a few ways of implementing this, but each fell short. Adding an auxiliary `_Idx` associated type to `Analysis` that defaults to `!` but is overridden in the blanket impl of `Analysis` for `A: GenKillAnalysis` to `A::Idx` seems promising, but the trait solver is unable to prove equivalence between `A::Idx` and `A::_Idx` within the overridden version of `into_engine`. Without full-featured specialization, removing `into_engine` or splitting it into a different trait would have a significant ergonomic penalty. Alternatively, we could erase the index type and store a `GenKillSet<u32>` as well as a function pointer for transmuting between `&mut A::Domain` and `&mut BitSet<u32>` in the hopes that LLVM can devirtualize a simple function pointer better than the boxed closure. However, this is brittle, requires `unsafe` code, and doesn't work for index types that aren't the same size as a `u32` (e.g. `usize`) since `GenKillSet` stores a `HybridBitSet`, which may be a `Vec<I>`. Perhaps safe transmute could help here? |
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| rustc | ||
| rustc_apfloat | ||
| rustc_arena | ||
| rustc_ast | ||
| rustc_ast_lowering | ||
| rustc_ast_passes | ||
| rustc_ast_pretty | ||
| rustc_attr | ||
| rustc_builtin_macros | ||
| rustc_codegen_llvm | ||
| rustc_codegen_ssa | ||
| rustc_data_structures | ||
| rustc_driver | ||
| rustc_error_codes | ||
| rustc_errors | ||
| rustc_expand | ||
| rustc_feature | ||
| rustc_fs_util | ||
| rustc_graphviz | ||
| rustc_hir | ||
| rustc_hir_pretty | ||
| rustc_incremental | ||
| rustc_index | ||
| rustc_infer | ||
| rustc_interface | ||
| rustc_lexer | ||
| rustc_lint | ||
| rustc_macros | ||
| rustc_metadata | ||
| rustc_middle | ||
| rustc_mir | ||
| rustc_mir_build | ||
| rustc_parse | ||
| rustc_parse_format | ||
| rustc_passes | ||
| rustc_plugin_impl | ||
| rustc_privacy | ||
| rustc_query_system | ||
| rustc_resolve | ||
| rustc_save_analysis | ||
| rustc_serialize | ||
| rustc_session | ||
| rustc_span | ||
| rustc_symbol_mangling | ||
| rustc_target | ||
| rustc_trait_selection | ||
| rustc_traits | ||
| rustc_ty | ||
| rustc_typeck | ||