Merge pull request #829 from kmod/perf4

Save the key hash in dictionaries

src/codegen/ast_interpreter.cpp

@@ -1837,7 +1837,7 @@ Box* astInterpretDeopt(CLFunction* clfunc, AST_expr* after_expr, AST_stmt* enclo
     assert(clfunc->source->scoping->areGlobalsFromModule());
     interpreter.setGlobals(source_info->parent_module);
 
-    for (const auto& p : frame_state.locals->d) {
+    for (const auto& p : *frame_state.locals) {
         assert(p.first->cls == str_cls);
         auto name = static_cast<BoxedString*>(p.first)->s();
         if (name == PASSED_GENERATOR_NAME) {

src/codegen/unwinding.cpp

@@ -1061,7 +1061,7 @@ Box* PythonFrameIterator::fastLocalsToBoxedLocals() {
     // TODO Right now d just has all the python variables that are *initialized*
     // But we also need to loop through all the uninitialized variables that we have
     // access to and delete them from the locals dict
-    for (const auto& p : d->d) {
+    for (const auto& p : *d) {
         Box* varname = p.first;
         Box* value = p.second;
         setitem(frame_info->boxedLocals, varname, value);

src/runtime/builtin_modules/sys.cpp

@@ -561,7 +561,7 @@ void setupSys() {
 
 void setupSysEnd() {
     std::vector<Box*, StlCompatAllocator<Box*>> builtin_module_names;
-    for (auto& p : sys_modules_dict->d) {
+    for (const auto& p : *sys_modules_dict) {
         builtin_module_names.push_back(p.first);
     }
 

src/runtime/classobj.cpp

@@ -102,7 +102,7 @@ Box* classobjNew(Box* _cls, Box* _name, Box* _bases, Box** _args) {
     made->giveAttr("__module__", boxString(getCurrentModule()->name()));
     made->giveAttr("__doc__", None);
 
-    for (auto& p : dict->d) {
+    for (const auto& p : *dict) {
         RELEASE_ASSERT(p.first->cls == str_cls, "");
         BoxedString* s = (BoxedString*)p.first;
         internStringMortalInplace(s);

src/runtime/dict.cpp

@@ -50,7 +50,7 @@ Box* dictRepr(BoxedDict* self) {
     try {
         chars.push_back('{');
         bool first = true;
-        for (const auto& p : self->d) {
+        for (const auto& p : *self) {
             if (!first) {
                 chars.push_back(',');
                 chars.push_back(' ');
@@ -93,7 +93,7 @@ Box* dictItems(BoxedDict* self) {
     BoxedList* rtn = new BoxedList();
 
     rtn->ensure(self->d.size());
-    for (const auto& p : self->d) {
+    for (const auto& p : *self) {
         BoxedTuple* t = BoxedTuple::create({ p.first, p.second });
         listAppendInternal(rtn, t);
     }
@@ -104,7 +104,7 @@ Box* dictItems(BoxedDict* self) {
 Box* dictValues(BoxedDict* self) {
     BoxedList* rtn = new BoxedList();
     rtn->ensure(self->d.size());
-    for (const auto& p : self->d) {
+    for (const auto& p : *self) {
         listAppendInternal(rtn, p.second);
     }
     return rtn;
@@ -115,7 +115,7 @@ Box* dictKeys(BoxedDict* self) {
 
     BoxedList* rtn = new BoxedList();
     rtn->ensure(self->d.size());
-    for (const auto& p : self->d) {
+    for (const auto& p : *self) {
         listAppendInternal(rtn, p.first);
     }
     return rtn;
@@ -357,7 +357,7 @@ extern "C" int PyDict_Next(PyObject* op, Py_ssize_t* ppos, PyObject** pkey, PyOb
         return 0;
     }
 
-    *pkey = (*it)->first;
+    *pkey = (*it)->first.value;
     *pvalue = (*it)->second;
 
     ++(*it);
@@ -470,7 +470,7 @@ Box* dictPopitem(BoxedDict* self) {
         raiseExcHelper(KeyError, "popitem(): dictionary is empty");
     }
 
-    Box* key = it->first;
+    Box* key = it->first.value;
     Box* value = it->second;
     self->d.erase(it);
 
@@ -563,7 +563,7 @@ Box* dictEq(BoxedDict* self, Box* _rhs) {
     if (self->d.size() != rhs->d.size())
         return False;
 
-    for (const auto& p : self->d) {
+    for (const auto& p : *self) {
         auto it = rhs->d.find(p.first);
         if (it == rhs->d.end())
             return False;
@@ -708,7 +708,7 @@ void BoxedDict::gcHandler(GCVisitor* v, Box* b) {
 
     BoxedDict* d = (BoxedDict*)b;
 
-    for (auto p : d->d) {
+    for (auto p : *d) {
         v->visit(p.first);
         v->visit(p.second);
     }

src/runtime/inline/dict.cpp

@@ -65,11 +65,11 @@ Box* dictIterNext(Box* s) {
 
     Box* rtn = nullptr;
     if (self->type == BoxedDictIterator::KeyIterator) {
-        rtn = self->it->first;
+        rtn = self->it->first.value;
     } else if (self->type == BoxedDictIterator::ValueIterator) {
         rtn = self->it->second;
     } else if (self->type == BoxedDictIterator::ItemIterator) {
-        rtn = BoxedTuple::create({ self->it->first, self->it->second });
+        rtn = BoxedTuple::create({ self->it->first.value, self->it->second });
     }
     ++self->it;
     return rtn;

src/runtime/objmodel.cpp

@@ -3335,7 +3335,7 @@ void rearrangeArguments(ParamReceiveSpec paramspec, const ParamNames* param_name
         assert(PyDict_Check(kwargs));
         BoxedDict* d_kwargs = static_cast<BoxedDict*>(kwargs);
 
-        for (auto& p : d_kwargs->d) {
+        for (const auto& p : *d_kwargs) {
             auto k = coerceUnicodeToStr(p.first);
 
             if (k->cls != str_cls)
@@ -5303,7 +5303,7 @@ Box* _typeNew(BoxedClass* metatype, BoxedString* name, BoxedTuple* bases, BoxedD
         made->setattr(dict_str, dict_descr, NULL);
     }
 
-    for (const auto& p : attr_dict->d) {
+    for (const auto& p : *attr_dict) {
         auto k = coerceUnicodeToStr(p.first);
 
         RELEASE_ASSERT(k->cls == str_cls, "");

src/runtime/tuple.cpp

@@ -350,7 +350,7 @@ extern "C" Box* tupleNew(Box* _cls, BoxedTuple* args, BoxedDict* kwargs) {
         } else {
             assert(kwargs_sz);
             auto const seq = *(kwargs->d.begin());
-            auto const kw = static_cast<BoxedString*>(seq.first);
+            auto const kw = static_cast<BoxedString*>(seq.first.value);
 
             if (kw->s() == "sequence")
                 elements = seq.second;

src/runtime/types.cpp

@@ -2380,7 +2380,7 @@ public:
                 assert(PyDict_Check(_container));
                 BoxedDict* container = static_cast<BoxedDict*>(_container);
 
-                for (const auto& p : container->d) {
+                for (const auto& p : *container) {
                     AttrWrapper::setitem(self, p.first, p.second);
                 }
             }

src/runtime/types.h

@@ -659,22 +659,36 @@ struct PyLt {
     bool operator()(Box*, Box*) const;
 };
 
-struct PythonLevelEq {
-    static bool isEqual(Box* lhs, Box* rhs) {
-        if (lhs == rhs)
+class BoxedDict : public Box {
+public:
+    // llvm::DenseMap doesn't store the original hash values, choosing to instead
+    // check for equality more often.  This is probably a good tradeoff when the keys
+    // are pointers and comparison is cheap, but we want to make sure that keys with
+    // different hash values don't get compared.
+    struct BoxAndHash {
+        Box* value;
+        size_t hash;
+
+        BoxAndHash(Box* value) : value(value), hash(PyHasher()(value)) {}
+        BoxAndHash(Box* value, size_t hash) : value(value), hash(hash) {}
+    };
+
+    struct Comparisons {
+        static bool isEqual(BoxAndHash lhs, BoxAndHash rhs) {
+            if (lhs.value == rhs.value)
                 return true;
-        if (rhs == getEmptyKey() || rhs == getTombstoneKey())
+            if (rhs.value == (Box*)-1 || rhs.value == (Box*)-2)
                 return false;
-        return PyEq()(lhs, rhs);
+            if (lhs.hash != rhs.hash)
+                return false;
+            return PyEq()(lhs.value, rhs.value);
         }
-    static Box* getEmptyKey() { return (Box*)-1; }
-    static Box* getTombstoneKey() { return (Box*)-2; }
-    static unsigned getHashValue(Box* val) { return PyHasher()(val); }
-};
+        static BoxAndHash getEmptyKey() { return BoxAndHash((Box*)-1, 0); }
+        static BoxAndHash getTombstoneKey() { return BoxAndHash((Box*)-2, 0); }
+        static unsigned getHashValue(BoxAndHash val) { return val.hash; }
+    };
 
-class BoxedDict : public Box {
-public:
-    typedef llvm::DenseMap<Box*, Box*, PythonLevelEq> DictMap;
+    typedef llvm::DenseMap<BoxAndHash, Box*, Comparisons> DictMap;
 
     DictMap d;
 
@@ -683,12 +697,32 @@ public:
     DEFAULT_CLASS_SIMPLE(dict_cls);
 
     Box* getOrNull(Box* k) {
-        const auto& p = d.find(k);
+        const auto& p = d.find(BoxAndHash(k));
         if (p != d.end())
             return p->second;
         return NULL;
     }
 
+    class iterator {
+    private:
+        DictMap::iterator it;
+
+    public:
+        iterator(DictMap::iterator it) : it(std::move(it)) {}
+
+        bool operator!=(const iterator& rhs) const { return it != rhs.it; }
+        bool operator==(const iterator& rhs) const { return it == rhs.it; }
+        iterator& operator++() {
+            ++it;
+            return *this;
+        }
+        std::pair<Box*, Box*> operator*() const { return std::make_pair(it->first.value, it->second); }
+        Box* first() const { return it->first.value; }
+    };
+
+    iterator begin() { return iterator(d.begin()); }
+    iterator end() { return iterator(d.end()); }
+
     static void gcHandler(GCVisitor* v, Box* b);
 };
 static_assert(sizeof(BoxedDict) == sizeof(PyDictObject), "");

src/runtime/util.cpp

@@ -225,7 +225,7 @@ extern "C" void dumpEx(void* p, int levels) {
 
             if (levels > 0) {
                 int i = 0;
-                for (auto t : d->d) {
+                for (auto t : *d) {
                     printf("\nKey:");
                     dumpEx(t.first, levels - 1);
                     printf("Value:");

test/tests/dict_internals.py

@@ -38,3 +38,20 @@ nan = float('nan')
 d[nan] = "hello world"
 print d[nan]
 
+
+
+# Dicts should not check __eq__ for values that have different hash values,
+# even if they internally cause a hash collision.
+class C(int):
+    def __eq__(self, rhs):
+        print "eq", self, rhs
+        raise Exception("Error, should not call __eq__!")
+
+    def __hash__(self):
+        print "hash", self
+        return self
+
+d = {}
+for i in xrange(1000):
+    d[C(i)] = i
+print len(d)