diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src/sroa.rs')
| -rw-r--r-- | compiler/rustc_mir_transform/src/sroa.rs | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/compiler/rustc_mir_transform/src/sroa.rs b/compiler/rustc_mir_transform/src/sroa.rs index 80c4b58a574..38769885f36 100644 --- a/compiler/rustc_mir_transform/src/sroa.rs +++ b/compiler/rustc_mir_transform/src/sroa.rs @@ -72,8 +72,12 @@ fn escaping_locals<'tcx>( return true; } if let ty::Adt(def, _args) = ty.kind() - && tcx.is_lang_item(def.did(), LangItem::DynMetadata) + && (def.repr().simd() || tcx.is_lang_item(def.did(), LangItem::DynMetadata)) { + // Exclude #[repr(simd)] types so that they are not de-optimized into an array + // (MCP#838 banned projections into SIMD types, but if the value is unused + // this pass sees "all the uses are of the fields" and expands it.) + // codegen wants to see the `DynMetadata<T>`, // not the inner reference-to-opaque-type. return true; |