gnv: Merge array and scalar branch together

Author: tesuji

compiler/rustc_mir_transform/src/gvn.rs

@@ -416,16 +416,9 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                     };
                     let ptr_imm = Immediate::new_pointer_with_meta(data, meta, &self.ecx);
                     ImmTy::from_immediate(ptr_imm, ty).into()
-                } else if matches!(kind, AggregateTy::Array) {
-                    let dest = self.ecx.allocate(ty, MemoryKind::Stack).ok()?;
-                    // FIXME: Can we speed it up by using `ecx.write_immediate(.ScalarPair(_), dest)`?
-                    for (field_index, op) in fields.iter().copied().enumerate() {
-                        let field_dest = self.ecx.project_field(&dest, field_index).ok()?;
-                        self.ecx.copy_op(op, &field_dest).ok()?;
-                    }
-                    let dest = dest.map_provenance(|prov| prov.as_immutable());
-                    dest.into()
-                } else if matches!(ty.abi, Abi::Scalar(..) | Abi::ScalarPair(..)) {
+                } else if matches!(kind, AggregateTy::Array)
+                    || matches!(ty.abi, Abi::Scalar(..) | Abi::ScalarPair(..))
+                {
                     let dest = self.ecx.allocate(ty, MemoryKind::Stack).ok()?;
                     let variant_dest = if let Some(variant) = variant {
                         self.ecx.project_downcast(&dest, variant).ok()?
@@ -437,9 +430,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                         self.ecx.copy_op(op, &field_dest).ok()?;
                     }
                     self.ecx.write_discriminant(variant.unwrap_or(FIRST_VARIANT), &dest).ok()?;
-                    self.ecx
-                        .alloc_mark_immutable(dest.ptr().provenance.unwrap().alloc_id())
-                        .ok()?;
+                    let dest = dest.map_provenance(|prov| prov.as_immutable());
                     dest.into()
                 } else {
                     return None;