Create a separate deduplication cache for static items

Author: oli-obk

compiler/rustc_codegen_llvm/src/consts.rs

@@ -227,7 +227,7 @@ impl<'ll> CodegenCx<'ll, '_> {
 
     pub(crate) fn get_static(&self, def_id: DefId) -> &'ll Value {
         let instance = Instance::mono(self.tcx, def_id);
-        if let Some(&g) = self.instances.borrow().get(&instance) {
+        if let Some(&g) = self.statics.borrow().get(&def_id) {
             return g;
         }
 
@@ -331,7 +331,7 @@ impl<'ll> CodegenCx<'ll, '_> {
             }
         }
 
-        self.instances.borrow_mut().insert(instance, g);
+        self.statics.borrow_mut().insert(def_id, g);
         g
     }
 }

compiler/rustc_codegen_llvm/src/context.rs

@@ -54,6 +54,9 @@ pub struct CodegenCx<'ll, 'tcx> {
 
     /// Cache instances of monomorphic and polymorphic items
     pub instances: RefCell<FxHashMap<Instance<'tcx>, &'ll Value>>,
+
+    /// Cache static's allocations
+    pub statics: RefCell<FxHashMap<DefId, &'ll Value>>,
     /// Cache generated vtables
     pub vtables:
         RefCell<FxHashMap<(Ty<'tcx>, Option<ty::PolyExistentialTraitRef<'tcx>>), &'ll Value>>,
@@ -467,6 +470,7 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
             llcx,
             codegen_unit,
             instances: Default::default(),
+            statics: Default::default(),
             vtables: Default::default(),
             const_str_cache: Default::default(),
             const_globals: Default::default(),

compiler/rustc_codegen_llvm/src/mono_item.rs

@@ -38,7 +38,7 @@ impl<'tcx> PreDefineMethods<'tcx> for CodegenCx<'_, 'tcx> {
             }
         }
 
-        self.instances.borrow_mut().insert(instance, g);
+        self.statics.borrow_mut().insert(def_id, g);
     }
 
     fn predefine_fn(