Changes in / [eba615c:0d70e0d]

File:

• src/ResolvExpr/ResolveAssertions.cc (modified) (3 diffs)

src/ResolvExpr/ResolveAssertions.cc

@@ -103 +103 @@
                         OpenVarSet openVars;
                         std::vector<DeferRef> assns;
-                        Cost cost;
 
                         OutType( const TypeEnvironment& env, const OpenVarSet& openVars, 
                                 const std::vector<DeferRef>& assns )
-                        : env(env), openVars(openVars), assns(assns), cost(Cost::infinity) {}
+                        : env(env), openVars(openVars), assns(assns) {}
                 };
 
@@ -141 +140 @@
                 using Element = CandidateEnvMerger::OutType;
         private:
+                using Memo = std::unordered_map<const Element*, Cost>;
+                mutable Memo cache;              ///< cache of element costs
                 const SymTab::Indexer& indexer;  ///< Indexer for costing
 
@@ -147 +148 @@
 
                 /// reports the cost of an element
-                Cost get( Element& x ) const {
-                        // check cached cost
-                        if ( x.cost != Cost::infinity ) return x.cost;
-
-                        // generate cost
-                        Cost k = Cost::zero;
-                        for ( const auto& assn : x.assns ) {
-                                k += computeConversionCost( 
-                                        assn.match.adjType, assn.decl->get_type(), indexer, x.env );
-                                
-                                // mark vars+specialization cost on function-type assertions
-                                Type* assnType = assn.match.cdata.id->get_type();
-                                FunctionType* func;
-                                if ( PointerType* ptr = dynamic_cast< PointerType* >( assnType ) ) {
-                                        func = dynamic_cast< FunctionType* >( ptr->base );
-                                } else {
-                                        func = dynamic_cast< FunctionType* >( assnType );
-                                }
-                                if ( ! func ) continue;
-                                
-                                for ( DeclarationWithType* formal : func->parameters ) {
-                                        k.decSpec( specCost( formal->get_type() ) );
-                                }
-                                k.incVar( func->forall.size() );
-                                for ( TypeDecl* td : func->forall ) {
-                                        k.decSpec( td->assertions.size() );
-                                }
+                Cost get( const Element& x ) const {
+                        Memo::const_iterator it = cache.find( &x );
+                        if ( it == cache.end() ) {
+                                Cost k = Cost::zero;
+                                for ( const auto& assn : x.assns ) {
+                                        k += computeConversionCost( 
+                                                assn.match.adjType, assn.decl->get_type(), indexer, x.env );
+                                        
+                                        // mark vars+specialization cost on function-type assertions
+                                        PointerType* ptr = dynamic_cast< PointerType* >( assn.decl->get_type() );
+                                        if ( ! ptr ) continue;
+                                        FunctionType* func = dynamic_cast< FunctionType* >( ptr->base );
+                                        if ( ! func ) continue;
+                                        
+                                        for ( DeclarationWithType* formal : func->parameters ) {
+                                                k.decSpec( specCost( formal->get_type() ) );
+                                        }
+                                        k.incVar( func->forall.size() );
+                                        for ( TypeDecl* td : func->forall ) {
+                                                k.decSpec( td->assertions.size() );
+                                        }
+                                }
+                                it = cache.emplace_hint( it, &x, k );
                         }
-
-                        // cache and return
-                        x.cost = k;
-                        return k;
+                        return it->second;
                 }
                 
                 /// compares elements by cost
-                bool operator() ( Element& a, Element& b ) const {
+                bool operator() ( const Element& a, const Element& b ) const {
                         return get( a ) < get( b );
                 }