Changeset 052cd71 for src/ResolvExpr/ResolveAssertions.cc

Timestamp:

Apr 26, 2019, 4:15:00 PM (5 years ago)

Author:

Aaron Moss <a3moss@…>

Branches:

ADT, arm-eh, ast-experimental, cleanup-dtors, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

9795142

Parents:

bd405fa

git-author:

Aaron Moss <a3moss@…> (04/26/19 15:44:58)

git-committer:

Aaron Moss <a3moss@…> (04/26/19 16:15:00)

Message:

revert unfruitful assertion caching attempt

File:

• src/ResolvExpr/ResolveAssertions.cc (modified) (12 diffs)

src/ResolvExpr/ResolveAssertions.cc

@@ -35 +35 @@
 #include "SynTree/Expression.h"     // for InferredParams
 #include "TypeEnvironment.h"        // for TypeEnvironment, etc.
-#include "typeops.h"                // for adjustExprType
+#include "typeops.h"                // for adjustExprType, specCost
 #include "Unify.h"                  // for unify
 
@@ -58 +58 @@
         using CandidateList = std::vector<AssnCandidate>;
 
-        /// Unique identifier for a yet-to-be-resolved assertion
-        struct AssnId {
-                DeclarationWithType* decl;  ///< Declaration of assertion
-                AssertionSetValue info;     ///< Information about assertion
-
-                AssnId(DeclarationWithType* decl, const AssertionSetValue& info) : decl(decl), info(info) {}
-        };
-
-        /// Cached assertion items
-        struct AssnCacheItem {
-                CandidateList matches;         ///< Possible matches for this assertion
-                std::vector<AssnId> deferIds;  ///< Deferred assertions which resolve to this item
-
-                AssnCacheItem( CandidateList&& m ) : matches(std::move(m)), deferIds() {}
-        };
-
-        /// Cache of resolved assertions
-        using AssnCache = std::unordered_map<std::string, AssnCacheItem>;
-
         /// Reference to single deferred item
         struct DeferRef {
-                const AssnCacheItem& item;
+                const DeclarationWithType* decl;
+                const AssertionSetValue& info;
                 const AssnCandidate& match;
         };
@@ -86 +68 @@
         /// Acts like indexed list of DeferRef
         struct DeferItem {
-                const AssnCache* cache;     ///< Cache storing assertion item
-                std::string key;            ///< Key into cache
-                
-                DeferItem( const AssnCache& cache, const std::string& key ) : cache(&cache), key(key) {}
-
-                bool empty() const { return cache->at(key).matches.empty(); }
-
-                CandidateList::size_type size() const { return cache->at(key).matches.size(); }
-
-                DeferRef operator[] ( unsigned i ) const {
-                        const AssnCacheItem& item = cache->at(key);
-                        return { item, item.matches[i] };
-                }
-
-                const DeclarationWithType* get_decl() const { return cache->at(key).deferIds[0].decl; }
-
-                // sortable by key
-                // TODO look into optimizing combination process with other sort orders (e.g. by number 
-                // of matches in candidate)
-                bool operator< ( const DeferItem& o ) const { return key < o.key; }
-                bool operator== ( const DeferItem& o ) const { return key == o.key; }
+                const DeclarationWithType* decl;
+                const AssertionSetValue& info;
+                CandidateList matches;
+
+                DeferItem( DeclarationWithType* decl, const AssertionSetValue& info, CandidateList&& matches )
+                : decl(decl), info(info), matches(std::move(matches)) {}
+
+                bool empty() const { return matches.empty(); }
+
+                CandidateList::size_type size() const { return matches.size(); }
+
+                DeferRef operator[] ( unsigned i ) const { return { decl, info, matches[i] }; }
         };
 
@@ -181 +154 @@
                                 for ( const auto& assn : x.assns ) {
                                         k += computeConversionCost( 
-                                                assn.match.adjType, assn.item.deferIds[0].decl->get_type(), indexer, 
-                                                x.env );
+                                                assn.match.adjType, assn.decl->get_type(), indexer, x.env );
                                 }
                                 it = cache.emplace_hint( it, &x, k );
@@ -253 +225 @@
 
         /// Resolve a single assertion, in context
-        bool resolveAssertion( AssertionItem& assn, ResnState& resn, AssnCache& cache ) {
+        bool resolveAssertion( AssertionItem& assn, ResnState& resn ) {
                 // skip unused assertions
                 if ( ! assn.info.isUsed ) return true;
 
-                // check cache for this assertion
-                std::string assnKey = SymTab::Mangler::mangleAssnKey( assn.decl, resn.alt.env );
-                auto it = cache.find( assnKey );
-
-                // attempt to resolve assertion if this is the first time seen
-                if ( it == cache.end() ) {
-                        // lookup candidates for this assertion
-                        std::list< SymTab::Indexer::IdData > candidates;
-                        resn.indexer.lookupId( assn.decl->name, candidates );
-
-                        // find the candidates that unify with the desired type
-                        CandidateList matches;
-                        for ( const auto& cdata : candidates ) {
-                                DeclarationWithType* candidate = cdata.id;
-
-                                // build independent unification context for candidate
-                                AssertionSet have, newNeed;
-                                TypeEnvironment newEnv{ resn.alt.env };
-                                OpenVarSet newOpenVars{ resn.alt.openVars };
-                                Type* adjType = candidate->get_type()->clone();
-                                adjustExprType( adjType, newEnv, resn.indexer );
-                                renameTyVars( adjType );
-
-                                // keep unifying candidates
-                                if ( unify( assn.decl->get_type(), adjType, newEnv, newNeed, have, newOpenVars, 
-                                                resn.indexer ) ) {
-                                        // set up binding slot for recursive assertions
-                                        UniqueId crntResnSlot = 0;
-                                        if ( ! newNeed.empty() ) {
-                                                crntResnSlot = ++globalResnSlot;
-                                                for ( auto& a : newNeed ) {
-                                                        a.second.resnSlot = crntResnSlot;
-                                                }
+                // lookup candidates for this assertion
+                std::list< SymTab::Indexer::IdData > candidates;
+                resn.indexer.lookupId( assn.decl->name, candidates );
+
+                // find the candidates that unify with the desired type
+                CandidateList matches;
+                for ( const auto& cdata : candidates ) {
+                        DeclarationWithType* candidate = cdata.id;
+
+                        // build independent unification context for candidate
+                        AssertionSet have, newNeed;
+                        TypeEnvironment newEnv{ resn.alt.env };
+                        OpenVarSet newOpenVars{ resn.alt.openVars };
+                        Type* adjType = candidate->get_type()->clone();
+                        adjustExprType( adjType, newEnv, resn.indexer );
+                        renameTyVars( adjType );
+
+                        // keep unifying candidates
+                        if ( unify( assn.decl->get_type(), adjType, newEnv, newNeed, have, newOpenVars, 
+                                        resn.indexer ) ) {
+                                // set up binding slot for recursive assertions
+                                UniqueId crntResnSlot = 0;
+                                if ( ! newNeed.empty() ) {
+                                        crntResnSlot = ++globalResnSlot;
+                                        for ( auto& a : newNeed ) {
+                                                a.second.resnSlot = crntResnSlot;
                                         }
-
-                                        matches.emplace_back( cdata, adjType, std::move(newEnv), std::move(have), 
-                                                std::move(newNeed), std::move(newOpenVars), crntResnSlot );
-                                } else {
-                                        delete adjType;
-                                }
+                                }
+
+                                matches.emplace_back( cdata, adjType, std::move(newEnv), std::move(have), 
+                                        std::move(newNeed), std::move(newOpenVars), crntResnSlot );
+                        } else {
+                                delete adjType;
                         }
-
-                        it = cache.emplace_hint( it, assnKey, AssnCacheItem{ std::move(matches) } );
-                }
-
-                CandidateList& matches = it->second.matches;
+                }
 
                 // break if no suitable assertion
@@ -309 +270 @@
                 // defer if too many suitable assertions
                 if ( matches.size() > 1 ) {
-                        it->second.deferIds.emplace_back( assn.decl, assn.info );
-                        resn.deferred.emplace_back( cache, assnKey );
+                        resn.deferred.emplace_back( assn.decl, assn.info, std::move(matches) );
                         return true;
                 }
@@ -318 +278 @@
                 addToIndexer( match.have, resn.indexer );
                 resn.newNeed.insert( match.need.begin(), match.need.end() );
-                resn.alt.env = match.env;
-                resn.alt.openVars = match.openVars;
+                resn.alt.env = std::move(match.env);
+                resn.alt.openVars = std::move(match.openVars);
 
                 bindAssertion( assn.decl, assn.info, resn.alt, match, resn.inferred );
@@ -380 +340 @@
                 ResnList resns{ ResnState{ alt, root_indexer } };
                 ResnList new_resns{};
-                AssnCache assnCache;
 
                 // resolve assertions in breadth-first-order up to a limited number of levels deep
@@ -389 +348 @@
                                 for ( auto& assn : resn.need ) {
                                         // fail early if any assertion is not resolvable
-                                        if ( ! resolveAssertion( assn, resn, assnCache ) ) {
+                                        if ( ! resolveAssertion( assn, resn ) ) {
                                                 Indenter tabs{ Indenter::tabsize, 3 };
                                                 std::ostringstream ss;
@@ -410 +369 @@
                                         }
                                 } else {
-                                        // only resolve each deferred assertion once
-                                        std::sort( resn.deferred.begin(), resn.deferred.end() );
-                                        auto last = std::unique( resn.deferred.begin(), resn.deferred.end() );
-                                        resn.deferred.erase( last, resn.deferred.end() );
                                         // resolve deferred assertions by mutual compatibility
                                         std::vector<CandidateEnvMerger::OutType> compatible = filterCombos(
@@ -427 +382 @@
                                                 ++tabs;
                                                 for ( const auto& d : resn.deferred ) {
-                                                        d.get_decl()->print( ss, tabs );
+                                                        d.decl->print( ss, tabs );
                                                 }
 
@@ -458 +413 @@
                                                         new_resn.newNeed.insert( match.need.begin(), match.need.end() );
 
-                                                        // for each deferred assertion with the same form
-                                                        for ( AssnId id : r.item.deferIds ) {
-                                                                bindAssertion( 
-                                                                        id.decl, id.info, new_resn.alt, match, new_resn.inferred );
-                                                        }
+                                                        bindAssertion( r.decl, r.info, new_resn.alt, match, new_resn.inferred );
                                                 }