Merge pull request #969 from kmod/unboxed3

Reenable unboxed values

src/analysis/type_analysis.cpp

@@ -57,15 +57,13 @@ ConcreteCompilerType* NullTypeAnalysis::getTypeAtBlockEnd(InternedString name, C
 
 
 // Note: the behavior of this function must match irgenerator.cpp::unboxVar()
-static ConcreteCompilerType* unboxedType(ConcreteCompilerType* t) {
+static CompilerType* unboxedType(ConcreteCompilerType* t) {
     if (t == BOXED_BOOL)
         return BOOL;
-#if ENABLE_UNBOXED_VALUES
     if (t == BOXED_INT)
         return INT;
     if (t == BOXED_FLOAT)
         return FLOAT;
-#endif
     return t;
 }
 
@@ -117,17 +115,17 @@ private:
         assert(speculation != TypeAnalysis::NONE);
 
         if (speculated_cls != NULL && speculated_cls->is_constant) {
-            ConcreteCompilerType* speculated_type = unboxedType(typeFromClass(speculated_cls));
+            CompilerType* speculated_type = unboxedType(typeFromClass(speculated_cls));
+            if (!old_type->canConvertTo(speculated_type)) {
                 if (VERBOSITY() >= 2) {
-                printf("in propagator, speculating that %s would actually be %s, at ", old_type->debugName().c_str(),
-                       speculated_type->debugName().c_str());
+                    printf("in propagator, speculating that %s would actually be %s, at ",
+                           old_type->debugName().c_str(), speculated_type->debugName().c_str());
                     fflush(stdout);
                     print_ast(node);
                     llvm::outs().flush();
                     printf("\n");
                 }
 
-            if (!old_type->canConvertTo(speculated_type)) {
                 type_speculations[node] = speculated_cls;
                 return speculated_type;
             }
@@ -147,6 +145,7 @@ private:
         }
 
         expr_types[node] = rtn;
+        assert(rtn->isUsable());
         return rtn;
     }
 
@@ -163,10 +162,12 @@ private:
         }
 
         expr_types[node] = rtn;
+        assert(rtn->isUsable());
         return rtn;
     }
 
     void _doSet(InternedString target, CompilerType* t) {
+        assert(t->isUsable());
         if (t)
             sym_table[target] = t;
     }
@@ -196,7 +197,7 @@ private:
         }
     }
 
-    void* visit_ellipsis(AST_Ellipsis* node) override { return ELLIPSIS; }
+    void* visit_ellipsis(AST_Ellipsis* node) override { return typeFromClass(ellipsis_cls); }
 
     void* visit_attribute(AST_Attribute* node) override {
         CompilerType* t = getType(node->value);

src/codegen/compvars.cpp

@@ -155,7 +155,7 @@ public:
         return var->getValue()->func->call(emitter, info, new_argspec, new_args, keyword_names);
     }
 
-    bool canConvertTo(ConcreteCompilerType* other_type) override { return other_type == UNKNOWN; }
+    bool canConvertTo(CompilerType* other_type) override { return other_type == UNKNOWN; }
     ConcreteCompilerType* getConcreteType() override { return typeFromClass(instancemethod_cls); }
     ConcreteCompilerType* getBoxType() override { return getConcreteType(); }
     ConcreteCompilerVariable* makeConverted(IREmitter& emitter, VAR* var, ConcreteCompilerType* other_type) override {
@@ -324,7 +324,7 @@ public:
         abort();
     }
 
-    ConcreteCompilerVariable* len(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var) override {
+    CompilerVariable* len(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var) override {
         bool do_patchpoint = ENABLE_ICGENERICS;
         llvm::Value* rtn;
         if (do_patchpoint) {
@@ -338,7 +338,7 @@ public:
             rtn = emitter.createCall(info.unw_info, g.funcs.unboxedLen, var->getValue());
         }
         assert(rtn->getType() == g.i64);
-        return new ConcreteCompilerVariable(INT, rtn, true);
+        return makeInt(rtn);
     }
 
     CompilerVariable* getitem(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var,
@@ -849,7 +849,7 @@ public:
 
     ConcreteCompilerType* getBoxType() override { return UNKNOWN; }
 
-    bool canConvertTo(ConcreteCompilerType* other_type) override { return other_type == UNKNOWN; }
+    bool canConvertTo(CompilerType* other_type) override { return other_type == UNKNOWN; }
 
     CompilerType* getattrType(BoxedString* attr, bool cls_only) override { return UNDEF; }
 
@@ -901,7 +901,7 @@ public:
 
             Sig* type_sig = new Sig();
             auto paramspec = rtfunc->getParamspec();
-            type_sig->rtn_type = fspec->rtn_type;
+            type_sig->rtn_type = fspec->rtn_type->getUsableType();
             type_sig->ndefaults = paramspec.num_defaults;
             type_sig->takes_varargs = paramspec.takes_varargs;
             type_sig->takes_kwargs = paramspec.takes_kwargs;
@@ -928,20 +928,143 @@ public:
     int numFrameArgs() override { abort(); }
 };
 
-class IntType : public ConcreteCompilerType {
+template <typename T> struct UnboxedVal {
+    T val;
+    ConcreteCompilerVariable* boxed;
+
+    UnboxedVal(T val, ConcreteCompilerVariable* boxed) : val(std::move(val)), boxed(boxed) {}
+};
+
+// XXX: make this a over a unique_ptr<UnboxedVal>
+template <typename T, typename D> class UnboxedType : public ValuedCompilerType<std::shared_ptr<UnboxedVal<T>>> {
 public:
-    IntType() {}
+    // Subclasses need to implement:
+    //   _makeConverted
+    //   _dup
+    //   _drop
+    //   _numFrameArgs
+    //   _serializeToFrame
+    //   _deserializeFromFrame
+    typedef UnboxedVal<T> Unboxed;
+    typedef typename ValuedCompilerType<std::shared_ptr<UnboxedVal<T>>>::VAR VAR;
 
-    llvm::Type* llvmType() override { return g.i64; }
+    void drop(IREmitter& emitter, VAR* var) override final {
+        auto v = var->getValue();
+        if (v->boxed)
+            v->boxed->decvref(emitter);
+        static_cast<D*>(this)->_drop(emitter, v->val);
+    }
 
-    bool isFitBy(BoxedClass* c) override { return false; }
+    void grab(IREmitter& emitter, VAR* var) override final { RELEASE_ASSERT(0, ""); }
 
-    void drop(IREmitter& emitter, ConcreteCompilerVariable* var) override {
-        // pass
+    void assertMatches(std::shared_ptr<Unboxed> val) override final {
+        static_cast<D*>(this)->_assertMatches(val->val);
+        assert(!val->boxed || val->boxed->getType() == static_cast<D*>(this)->getBoxType());
     }
-    void grab(IREmitter& emitter, ConcreteCompilerVariable* var) override {
-        // pass
+
+    CompilerVariable* dup(VAR* var, DupCache& cache) override final {
+        CompilerVariable*& rtn = cache[var];
+
+        if (rtn == NULL) {
+            auto orig_v = var->getValue();
+
+            T val_duped = static_cast<D*>(this)->_dup(orig_v->val, cache);
+
+            CompilerVariable* box_duped = orig_v->boxed ? orig_v->boxed->dup(cache) : NULL;
+            assert(!box_duped || box_duped->getType() == box_duped->getType()->getBoxType());
+
+            auto val
+                = std::make_shared<Unboxed>(std::move(val_duped), static_cast<ConcreteCompilerVariable*>(box_duped));
+            rtn = new VAR(this, val, var->isGrabbed());
+            while (rtn->getVrefs() < var->getVrefs())
+                rtn->incvref();
+        }
+        return rtn;
+    }
+
+    ConcreteCompilerType* getConcreteType() override final { return this->getBoxType(); }
+
+    bool canConvertTo(CompilerType* other_type) override final {
+        return (other_type == this || other_type == UNKNOWN || other_type == this->getBoxType());
+    }
+
+    ConcreteCompilerVariable* makeConverted(IREmitter& emitter, VAR* var,
+                                            ConcreteCompilerType* other_type) override final {
+        assert(canConvertTo(other_type));
+
+        auto val = var->getValue();
+        ConcreteCompilerVariable* boxed = val->boxed;
+
+        if (!boxed) {
+            boxed = static_cast<D*>(this)->_makeConverted(emitter, val->val, this->getBoxType());
+            ASSERT(boxed->getType() == this->getBoxType(), "%s %s", boxed->getType()->debugName().c_str(),
+                   this->getBoxType()->debugName().c_str());
+
+            val->boxed = boxed;
+        }
+
+        if (boxed->getType() != other_type) {
+            assert(other_type == UNKNOWN);
+            return boxed->makeConverted(emitter, other_type);
+        }
+
+        boxed->incvref();
+        return boxed;
+    }
+
+    // Serialization strategy is a bit silly for now: we will emit a bool saying whether we emitted the
+    // boxed or unboxed value.  There's no reason that has to be in the serialization though (it could
+    // be in the metadata), and we shouldn't have to pad the smaller version to the size of the larger one.
+    int numFrameArgs() override final {
+        return 1 + std::max(static_cast<D*>(this)->_numFrameArgs(), this->getBoxType()->numFrameArgs());
+    }
+
+    void serializeToFrame(VAR* var, std::vector<llvm::Value*>& stackmap_args) override final {
+        auto v = var->getValue();
+
+        int total_args = numFrameArgs();
+        int needed_args = stackmap_args.size() + total_args;
+
+        if (v->boxed) {
+            stackmap_args.push_back(getConstantInt(1, g.i64));
+            v->boxed->serializeToFrame(stackmap_args);
+        } else {
+            stackmap_args.push_back(getConstantInt(0, g.i64));
+            static_cast<D*>(this)->_serializeToFrame(v->val, stackmap_args);
+        }
+
+        while (stackmap_args.size() < needed_args)
+            stackmap_args.push_back(getConstantInt(0, g.i64));
+    }
+
+    Box* deserializeFromFrame(const FrameVals& vals) override final {
+        assert(vals.size() == numFrameArgs());
+
+
+        bool is_boxed = vals[0];
+
+        if (is_boxed) {
+            // TODO: inefficient
+            FrameVals sub_vals(vals.begin() + 1, vals.begin() + 1 + this->getBoxType()->numFrameArgs());
+            return this->getBoxType()->deserializeFromFrame(sub_vals);
+        } else {
+            FrameVals sub_vals(vals.begin() + 1, vals.begin() + 1 + static_cast<D*>(this)->_numFrameArgs());
+            return static_cast<D*>(this)->_deserializeFromFrame(sub_vals);
         }
+    }
+};
+
+class IntType : public UnboxedType<llvm::Value*, IntType> {
+public:
+    IntType() {}
+
+    void _drop(IREmitter& emitter, llvm::Value* v) {}
+
+    llvm::Value* _dup(llvm::Value* v, DupCache& cache) { return v; }
+
+    void _assertMatches(llvm::Value* v) { assert(v->getType() == g.i64); }
+
+    std::string debugName() override { return "int"; }
 
     CompilerType* getattrType(BoxedString* attr, bool cls_only) override {
         /*
@@ -974,8 +1097,8 @@ public:
         static std::vector<AbstractFunctionType::Sig*> sigs;
         if (sigs.size() == 0) {
             AbstractFunctionType::Sig* int__float_sig = new AbstractFunctionType::Sig();
-            int__float_sig->rtn_type = FLOAT;
-            int__float_sig->arg_types.push_back(FLOAT);
+            int__float_sig->rtn_type = UNBOXED_FLOAT;
+            int__float_sig->arg_types.push_back(UNBOXED_FLOAT);
             sigs.push_back(int__float_sig);
 
             AbstractFunctionType::Sig* unknown_sig = new AbstractFunctionType::Sig();
@@ -993,8 +1116,8 @@ public:
         return BOXED_INT->getattrType(attr, cls_only);
     }
 
-    CompilerVariable* callattr(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var, BoxedString* attr,
-                               CallattrFlags flags, const std::vector<CompilerVariable*>& args,
+    CompilerVariable* callattr(IREmitter& emitter, const OpInfo& info, VAR* var, BoxedString* attr, CallattrFlags flags,
+                               const std::vector<CompilerVariable*>& args,
                                const std::vector<BoxedString*>* keyword_names) override {
         ConcreteCompilerVariable* converted = var->makeConverted(emitter, BOXED_INT);
         CompilerVariable* rtn = converted->callattr(emitter, info, attr, flags, args, keyword_names);
@@ -1002,7 +1125,7 @@ public:
         return rtn;
     }
 
-    CompilerVariable* getattr(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var, BoxedString* attr,
+    CompilerVariable* getattr(IREmitter& emitter, const OpInfo& info, VAR* var, BoxedString* attr,
                               bool cls_only) override {
         ConcreteCompilerVariable* converted = var->makeConverted(emitter, BOXED_INT);
         CompilerVariable* rtn = converted->getattr(emitter, info, attr, cls_only);
@@ -1024,24 +1147,16 @@ public:
         call.setDoesNotReturn();
     }
 
-    ConcreteCompilerVariable* makeConverted(IREmitter& emitter, ConcreteCompilerVariable* var,
-                                            ConcreteCompilerType* other_type) override {
-        if (other_type == this) {
-            var->incvref();
-            return var;
-        } else if (other_type == UNKNOWN || other_type == BOXED_INT) {
-            llvm::Value* unboxed = var->getValue();
+    ConcreteCompilerVariable* _makeConverted(IREmitter& emitter, llvm::Value* unboxed,
+                                             ConcreteCompilerType* other_type) {
+        assert(other_type == BOXED_INT);
         llvm::Value* boxed;
         if (llvm::ConstantInt* llvm_val = llvm::dyn_cast<llvm::ConstantInt>(unboxed)) {
             boxed = embedRelocatablePtr(emitter.getIntConstant(llvm_val->getSExtValue()), g.llvm_value_type_ptr);
         } else {
-                boxed = emitter.getBuilder()->CreateCall(g.funcs.boxInt, var->getValue());
+            boxed = emitter.getBuilder()->CreateCall(g.funcs.boxInt, unboxed);
         }
         return new ConcreteCompilerVariable(other_type, boxed, true);
-        } else {
-            printf("Don't know how to convert i64 to %s\n", other_type->debugName().c_str());
-            abort();
-        }
     }
 
     CompilerVariable* getitem(IREmitter& emitter, const OpInfo& info, VAR* var, CompilerVariable* slice) override {
@@ -1051,21 +1166,21 @@ public:
         return rtn;
     }
 
-    ConcreteCompilerVariable* len(IREmitter& emitter, const OpInfo& info, VAR* var) override {
+    CompilerVariable* len(IREmitter& emitter, const OpInfo& info, VAR* var) override {
         llvm::CallSite call
             = emitter.createCall(info.unw_info, g.funcs.raiseNotIterableError, embedConstantPtr("int", g.i8_ptr));
         call.setDoesNotReturn();
-        return new ConcreteCompilerVariable(INT, llvm::UndefValue::get(g.i64), true);
+        return makeInt(llvm::UndefValue::get(g.i64));
     }
 
-    ConcreteCompilerVariable* nonzero(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var) override {
-        llvm::Value* cmp = emitter.getBuilder()->CreateICmpNE(var->getValue(), llvm::ConstantInt::get(g.i64, 0, false));
+    ConcreteCompilerVariable* nonzero(IREmitter& emitter, const OpInfo& info, VAR* var) override {
+        llvm::Value* cmp
+            = emitter.getBuilder()->CreateICmpNE(var->getValue()->val, llvm::ConstantInt::get(g.i64, 0, false));
         return boolFromI1(emitter, cmp);
     }
 
-    ConcreteCompilerVariable* unaryop(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var,
-                                      AST_TYPE::AST_TYPE op_type) override {
-        llvm::Value* unboxed = var->getValue();
+    CompilerVariable* unaryop(IREmitter& emitter, const OpInfo& info, VAR* var, AST_TYPE::AST_TYPE op_type) override {
+        llvm::Value* unboxed = var->getValue()->val;
         if (op_type == AST_TYPE::USub) {
             if (llvm::ConstantInt* llvm_val = llvm::dyn_cast<llvm::ConstantInt>(unboxed)) {
                 int64_t val = llvm_val->getSExtValue();
@@ -1092,10 +1207,8 @@ public:
                 if (op_type == AST_TYPE::IsNot || op_type == AST_TYPE::Is)
                     return makeBool(op_type == AST_TYPE::IsNot);
 
-                ConcreteCompilerVariable* converted_left = var->makeConverted(emitter, INT);
-                llvm::Value* conv = emitter.getBuilder()->CreateSIToFP(converted_left->getValue(), g.double_);
-                converted_left->decvref(emitter);
-                converted_left = new ConcreteCompilerVariable(FLOAT, conv, true);
+                llvm::Value* conv = emitter.getBuilder()->CreateSIToFP(var->getValue()->val, g.double_);
+                auto converted_left = makeFloat(conv);
                 return converted_left->binexp(emitter, info, rhs, op_type, exp_type);
             }
 
@@ -1105,7 +1218,8 @@ public:
             return rtn;
         }
 
-        ConcreteCompilerVariable* converted_right = rhs->makeConverted(emitter, INT);
+        assert(rhs->getType() == INT);
+        llvm::Value* right_val = static_cast<VAR*>(rhs)->getValue()->val;
         llvm::Value* v;
         /*if (op_type == AST_TYPE::Mod) {
             v = emitter.createCall2(info.unw_info, g.funcs.mod_i64_i64, var->getValue(), converted_right->getValue())
@@ -1178,15 +1292,11 @@ public:
                     abort();
                     break;
             }
-            v = emitter.getBuilder()->CreateICmp(cmp_pred, var->getValue(), converted_right->getValue());
+            v = emitter.getBuilder()->CreateICmp(cmp_pred, var->getValue()->val, right_val);
         }
-        converted_right->decvref(emitter);
-        if (v->getType() == g.i64) {
-            return new ConcreteCompilerVariable(INT, v, true);
-        } else {
+        assert(v->getType() == g.i1);
         return boolFromI1(emitter, v);
     }
-    }
 
     CompilerVariable* contains(IREmitter& emitter, const OpInfo& info, VAR* var, CompilerVariable* lhs) override {
         llvm::CallSite call
@@ -1197,44 +1307,68 @@ public:
 
     ConcreteCompilerType* getBoxType() override { return BOXED_INT; }
 
-    Box* deserializeFromFrame(const FrameVals& vals) override {
+    int _numFrameArgs() { return 1; }
+
+    Box* _deserializeFromFrame(const FrameVals& vals) {
         assert(vals.size() == 1);
 
         return boxInt(vals[0]);
     }
+
+    void _serializeToFrame(llvm::Value* val, std::vector<llvm::Value*>& stackmap_args) { stackmap_args.push_back(val); }
+
+    static llvm::Value* extractInt(CompilerVariable* v) {
+        assert(v->getType() == INT);
+        return static_cast<VAR*>(v)->getValue()->val;
+    }
 } _INT;
-ConcreteCompilerType* INT = &_INT;
+CompilerType* INT = &_INT;
+
+CompilerVariable* makeInt(llvm::Value* n) {
+    assert(n->getType() == g.i64);
+    return new IntType::VAR(&_INT, std::make_shared<IntType::Unboxed>(n, nullptr), true);
+}
+
+CompilerVariable* makeInt(int64_t n) {
+    return makeInt(llvm::ConstantInt::get(g.i64, n, true));
+}
 
-ConcreteCompilerVariable* makeInt(int64_t n) {
-    return new ConcreteCompilerVariable(INT, llvm::ConstantInt::get(g.i64, n, true), true);
+CompilerVariable* makeUnboxedInt(IREmitter& emitter, ConcreteCompilerVariable* v) {
+    assert(v->getType() == BOXED_INT);
+    llvm::Value* unboxed = emitter.getBuilder()->CreateCall(g.funcs.unboxInt, v->getValue());
+    return new IntType::VAR(&_INT, std::make_shared<IntType::Unboxed>(unboxed, v), true);
 }
 
-class FloatType : public ConcreteCompilerType {
+CompilerVariable* makeUnboxedInt(IREmitter& emitter, llvm::Value* v) {
+    assert(v->getType() == g.llvm_value_type_ptr);
+    return makeUnboxedInt(emitter, new ConcreteCompilerVariable(BOXED_INT, v, false));
+}
+
+class FloatType : public UnboxedType<llvm::Value*, FloatType> {
 public:
     FloatType() {}
 
-    llvm::Type* llvmType() override { return g.double_; }
+    std::string debugName() override { return "float"; }
 
-    bool isFitBy(BoxedClass* c) override { return false; }
-
-    void drop(IREmitter& emitter, ConcreteCompilerVariable* var) override {
-        // pass
-    }
-    void grab(IREmitter& emitter, ConcreteCompilerVariable* var) override {
+    void _drop(IREmitter& emitter, llvm::Value* v) {
         // pass
     }
 
+    void _assertMatches(llvm::Value* v) { assert(v->getType() == g.double_); }
+
+    llvm::Value* _dup(llvm::Value* v, DupCache& cache) { return v; }
+
     CompilerType* getattrType(BoxedString* attr, bool cls_only) override {
         static std::vector<AbstractFunctionType::Sig*> sigs;
         if (sigs.size() == 0) {
             AbstractFunctionType::Sig* float_sig = new AbstractFunctionType::Sig();
-            float_sig->rtn_type = FLOAT;
-            float_sig->arg_types.push_back(FLOAT);
+            float_sig->rtn_type = UNBOXED_FLOAT;
+            float_sig->arg_types.push_back(UNBOXED_FLOAT);
             sigs.push_back(float_sig);
 
             AbstractFunctionType::Sig* int_sig = new AbstractFunctionType::Sig();
-            int_sig->rtn_type = FLOAT;
-            int_sig->arg_types.push_back(INT);
+            int_sig->rtn_type = UNBOXED_FLOAT;
+            int_sig->arg_types.push_back(UNBOXED_INT);
             sigs.push_back(int_sig);
 
             AbstractFunctionType::Sig* unknown_sig = new AbstractFunctionType::Sig();
@@ -1258,7 +1392,7 @@ public:
         return BOXED_FLOAT->getattrType(attr, cls_only);
     }
 
-    CompilerVariable* getattr(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var, BoxedString* attr,
+    CompilerVariable* getattr(IREmitter& emitter, const OpInfo& info, VAR* var, BoxedString* attr,
                               bool cls_only) override {
         ConcreteCompilerVariable* converted = var->makeConverted(emitter, BOXED_FLOAT);
         CompilerVariable* rtn = converted->getattr(emitter, info, attr, cls_only);
@@ -1266,8 +1400,8 @@ public:
         return rtn;
     }
 
-    CompilerVariable* callattr(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var, BoxedString* attr,
-                               CallattrFlags flags, const std::vector<CompilerVariable*>& args,
+    CompilerVariable* callattr(IREmitter& emitter, const OpInfo& info, VAR* var, BoxedString* attr, CallattrFlags flags,
+                               const std::vector<CompilerVariable*>& args,
                                const std::vector<BoxedString*>* keyword_names) override {
         ConcreteCompilerVariable* converted = var->makeConverted(emitter, BOXED_FLOAT);
         CompilerVariable* rtn = converted->callattr(emitter, info, attr, flags, args, keyword_names);
@@ -1289,35 +1423,27 @@ public:
         call.setDoesNotReturn();
     }
 
-    ConcreteCompilerVariable* makeConverted(IREmitter& emitter, ConcreteCompilerVariable* var,
-                                            ConcreteCompilerType* other_type) override {
-        if (other_type == this) {
-            var->incvref();
-            return var;
-        } else if (other_type == UNKNOWN || other_type == BOXED_FLOAT) {
-            llvm::Value* unboxed = var->getValue();
+    ConcreteCompilerVariable* _makeConverted(IREmitter& emitter, llvm::Value* unboxed,
+                                             ConcreteCompilerType* other_type) {
+        assert(other_type == BOXED_FLOAT);
         llvm::Value* boxed;
         if (llvm::ConstantFP* llvm_val = llvm::dyn_cast<llvm::ConstantFP>(unboxed)) {
             // Will this ever hit the cache?
             boxed = embedRelocatablePtr(emitter.getFloatConstant(llvm_val->getValueAPF().convertToDouble()),
                                         g.llvm_value_type_ptr);
         } else {
-                boxed = emitter.getBuilder()->CreateCall(g.funcs.boxFloat, var->getValue());
+            boxed = emitter.getBuilder()->CreateCall(g.funcs.boxFloat, unboxed);
         }
         return new ConcreteCompilerVariable(other_type, boxed, true);
-        } else {
-            printf("Don't know how to convert float to %s\n", other_type->debugName().c_str());
-            abort();
-        }
     }
 
-    ConcreteCompilerVariable* nonzero(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var) override {
-        llvm::Value* cmp = emitter.getBuilder()->CreateFCmpUNE(var->getValue(), llvm::ConstantFP::get(g.double_, 0));
+    ConcreteCompilerVariable* nonzero(IREmitter& emitter, const OpInfo& info, VAR* var) override {
+        llvm::Value* cmp
+            = emitter.getBuilder()->CreateFCmpUNE(var->getValue()->val, llvm::ConstantFP::get(g.double_, 0));
         return boolFromI1(emitter, cmp);
     }
 
-    ConcreteCompilerVariable* unaryop(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var,
-                                      AST_TYPE::AST_TYPE op_type) override {
+    CompilerVariable* unaryop(IREmitter& emitter, const OpInfo& info, VAR* var, AST_TYPE::AST_TYPE op_type) override {
         ConcreteCompilerVariable* converted = var->makeConverted(emitter, BOXED_FLOAT);
         auto rtn = converted->unaryop(emitter, info, op_type);
         converted->decvref(emitter);
@@ -1333,6 +1459,8 @@ public:
 
     CompilerVariable* binexp(IREmitter& emitter, const OpInfo& info, VAR* var, CompilerVariable* rhs,
                              AST_TYPE::AST_TYPE op_type, BinExpType exp_type) override {
+        assert(rhs->getType() != UNBOXED_FLOAT); // we could handle this here but it shouldn't happen
+
         if (rhs->getType() != INT && rhs->getType() != FLOAT) {
             ConcreteCompilerVariable* converted = var->makeConverted(emitter, BOXED_FLOAT);
             CompilerVariable* rtn = converted->binexp(emitter, info, rhs, op_type, exp_type);
@@ -1340,33 +1468,28 @@ public:
             return rtn;
         }
 
-        ConcreteCompilerVariable* converted_right;
+        llvm::Value* rhs_val;
         if (rhs->getType() == FLOAT) {
-            converted_right = rhs->makeConverted(emitter, FLOAT);
+            rhs_val = static_cast<FloatType::VAR*>(rhs)->getValue()->val;
         } else {
             if (op_type == AST_TYPE::IsNot || op_type == AST_TYPE::Is)
                 return makeBool(op_type == AST_TYPE::IsNot);
 
-            converted_right = rhs->makeConverted(emitter, INT);
-            llvm::Value* conv = emitter.getBuilder()->CreateSIToFP(converted_right->getValue(), g.double_);
-            converted_right->decvref(emitter);
-            converted_right = new ConcreteCompilerVariable(FLOAT, conv, true);
+            assert(rhs->getType() == INT);
+            llvm::Value* right_val = IntType::extractInt(rhs);
+            rhs_val = emitter.getBuilder()->CreateSIToFP(right_val, g.double_);
         }
 
         llvm::Value* v;
         bool succeeded = true;
         if (op_type == AST_TYPE::Mod) {
-            v = emitter.createCall2(info.unw_info, g.funcs.mod_float_float, var->getValue(),
-                                    converted_right->getValue());
+            v = emitter.createCall2(info.unw_info, g.funcs.mod_float_float, var->getValue()->val, rhs_val);
         } else if (op_type == AST_TYPE::Div || op_type == AST_TYPE::TrueDiv) {
-            v = emitter.createCall2(info.unw_info, g.funcs.div_float_float, var->getValue(),
-                                    converted_right->getValue());
+            v = emitter.createCall2(info.unw_info, g.funcs.div_float_float, var->getValue()->val, rhs_val);
         } else if (op_type == AST_TYPE::FloorDiv) {
-            v = emitter.createCall2(info.unw_info, g.funcs.floordiv_float_float, var->getValue(),
-                                    converted_right->getValue());
+            v = emitter.createCall2(info.unw_info, g.funcs.floordiv_float_float, var->getValue()->val, rhs_val);
         } else if (op_type == AST_TYPE::Pow) {
-            v = emitter.createCall2(info.unw_info, g.funcs.pow_float_float, var->getValue(),
-                                    converted_right->getValue());
+            v = emitter.createCall2(info.unw_info, g.funcs.pow_float_float, var->getValue()->val, rhs_val);
         } else if (exp_type == BinOp || exp_type == AugBinOp) {
             llvm::Instruction::BinaryOps binopcode;
             switch (op_type) {
@@ -1393,7 +1516,7 @@ public:
             }
 
             if (succeeded) {
-                v = emitter.getBuilder()->CreateBinOp(binopcode, var->getValue(), converted_right->getValue());
+                v = emitter.getBuilder()->CreateBinOp(binopcode, var->getValue()->val, rhs_val);
             }
         } else {
             assert(exp_type == Compare);
@@ -1424,13 +1547,12 @@ public:
                     abort();
                     break;
             }
-            v = emitter.getBuilder()->CreateFCmp(cmp_pred, var->getValue(), converted_right->getValue());
+            v = emitter.getBuilder()->CreateFCmp(cmp_pred, var->getValue()->val, rhs_val);
         }
-        converted_right->decvref(emitter);
 
         if (succeeded) {
             if (v->getType() == g.double_) {
-                return new ConcreteCompilerVariable(FLOAT, v, true);
+                return makeFloat(v);
             } else {
                 return boolFromI1(emitter, v);
             }
@@ -1452,19 +1574,60 @@ public:
 
     ConcreteCompilerType* getBoxType() override { return BOXED_FLOAT; }
 
-    Box* deserializeFromFrame(const FrameVals& vals) override {
+    int _numFrameArgs() { return 1; }
+
+    void _serializeToFrame(llvm::Value* v, std::vector<llvm::Value*>& stackmap_args) { stackmap_args.push_back(v); }
+
+    Box* _deserializeFromFrame(const FrameVals& vals) {
         assert(vals.size() == 1);
 
         double d = *reinterpret_cast<const double*>(&vals[0]);
         return boxFloat(d);
     }
 } _FLOAT;
-ConcreteCompilerType* FLOAT = &_FLOAT;
+CompilerType* FLOAT = &_FLOAT;
+
+class PhonyUnboxedType : public ConcreteCompilerType {
+private:
+    llvm::Type* t;
+    CompilerType* usable_type;
+
+public:
+    PhonyUnboxedType(llvm::Type* t, CompilerType* usable_type) : t(t), usable_type(usable_type) {}
+
+    std::string debugName() { return "phony(" + ConcreteCompilerType::debugName() + ")"; }
+
+    CompilerType* getUsableType() override { return usable_type; }
+
+    llvm::Type* llvmType() override { return t; }
+
+    Box* deserializeFromFrame(const FrameVals& vals) override { RELEASE_ASSERT(0, "unavailable for phony types"); }
+};
+
+ConcreteCompilerType* UNBOXED_INT = new PhonyUnboxedType(llvm::Type::getInt64Ty(llvm::getGlobalContext()), INT);
+ConcreteCompilerType* UNBOXED_FLOAT = new PhonyUnboxedType(llvm::Type::getDoubleTy(llvm::getGlobalContext()), FLOAT);
 
-ConcreteCompilerVariable* makeFloat(double d) {
-    return new ConcreteCompilerVariable(FLOAT, llvm::ConstantFP::get(g.double_, d), true);
+CompilerVariable* makeFloat(llvm::Value* n) {
+    assert(n->getType() == g.double_);
+    return new FloatType::VAR(&_FLOAT, std::make_shared<FloatType::Unboxed>(n, nullptr), true);
 }
 
+CompilerVariable* makeFloat(double n) {
+    return makeFloat(llvm::ConstantFP::get(g.double_, n));
+}
+
+CompilerVariable* makeUnboxedFloat(IREmitter& emitter, ConcreteCompilerVariable* v) {
+    assert(v->getType() == BOXED_FLOAT);
+    llvm::Value* unboxed = emitter.getBuilder()->CreateCall(g.funcs.unboxFloat, v->getValue());
+    return new FloatType::VAR(&_FLOAT, std::make_shared<FloatType::Unboxed>(unboxed, v), true);
+}
+
+CompilerVariable* makeUnboxedFloat(IREmitter& emitter, llvm::Value* v) {
+    assert(v->getType() == g.llvm_value_type_ptr);
+    return makeUnboxedFloat(emitter, new ConcreteCompilerVariable(BOXED_FLOAT, v, false));
+}
+
+
 ConcreteCompilerVariable* makeLong(Box* v) {
     return new ConcreteCompilerVariable(LONG, embedRelocatablePtr(v, g.llvm_value_type_ptr), true);
 }
@@ -1638,11 +1801,11 @@ public:
         return rtn;
     }
 
-    ConcreteCompilerVariable* tryCallattrConstant(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var,
+    CompilerVariable* tryCallattrConstant(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var,
                                           BoxedString* attr, bool clsonly, ArgPassSpec argspec,
                                           const std::vector<CompilerVariable*>& args,
-                                                  const std::vector<BoxedString*>* keyword_names,
-                                                  bool* no_attribute = NULL, ExceptionStyle exception_style = CXX) {
+                                          const std::vector<BoxedString*>* keyword_names, bool* no_attribute = NULL,
+                                          ExceptionStyle exception_style = CXX) {
         if (!canStaticallyResolveGetattrs())
             return NULL;
 
@@ -1770,27 +1933,25 @@ public:
         ConcreteCompilerVariable* rtn = _call(emitter, info, linked_function, cf->exception_style, cf->code, other_args,
                                               argspec, new_args, keyword_names, cf->spec->rtn_type);
         assert(rtn->getType() == cf->spec->rtn_type);
-        assert(rtn->getType() != UNDEF);
+        ConcreteCompilerType* rtn_type = rtn->getType();
+
+        assert(rtn_type != UNDEF);
 
         // We should provide unboxed versions of these rather than boxing then unboxing:
         // TODO is it more efficient to unbox here, or should we leave it boxed?
-        if (cf->spec->rtn_type == BOXED_BOOL) {
+        if (rtn_type == BOXED_BOOL) {
             llvm::Value* unboxed = emitter.getBuilder()->CreateCall(g.funcs.unboxBool, rtn->getValue());
             return boolFromI1(emitter, unboxed);
         }
-#if ENABLE_UNBOXED_VALUES
-        if (cf->spec->rtn_type == BOXED_INT) {
-            llvm::Value* unboxed = emitter.getBuilder()->CreateCall(g.funcs.unboxInt, rtn->getValue());
-            return new ConcreteCompilerVariable(INT, unboxed, true);
+        if (rtn_type == BOXED_INT) {
+            return makeUnboxedInt(emitter, rtn);
         }
-        if (cf->spec->rtn_type == BOXED_FLOAT) {
-            llvm::Value* unboxed = emitter.getBuilder()->CreateCall(g.funcs.unboxFloat, rtn->getValue());
-            return new ConcreteCompilerVariable(FLOAT, unboxed, true);
+        if (rtn_type == UNBOXED_INT) {
+            return makeInt(rtn->getValue());
+        }
+        if (rtn_type == BOXED_FLOAT) {
+            return makeUnboxedFloat(emitter, rtn);
         }
-        assert(cf->spec->rtn_type != BOXED_INT);
-        assert(cf->spec->rtn_type != BOXED_FLOAT);
-#endif
-        ASSERT(cf->spec->rtn_type != BOXED_BOOL, "%p", cf->code);
 
         return rtn;
     }
@@ -1800,8 +1961,8 @@ public:
                                const std::vector<BoxedString*>* keyword_names) override {
         ExceptionStyle exception_style = info.preferredExceptionStyle();
 
-        ConcreteCompilerVariable* called_constant = tryCallattrConstant(
-            emitter, info, var, attr, flags.cls_only, flags.argspec, args, keyword_names, NULL, exception_style);
+        CompilerVariable* called_constant = tryCallattrConstant(emitter, info, var, attr, flags.cls_only, flags.argspec,
+                                                                args, keyword_names, NULL, exception_style);
 
         if (called_constant)
             return called_constant;
@@ -1827,7 +1988,7 @@ public:
 
                 bool no_attribute = false;
 
-                ConcreteCompilerVariable* called_constant
+                CompilerVariable* called_constant
                     = tryCallattrConstant(emitter, info, var, left_side_name, true, ArgPassSpec(1, 0, 0, 0),
                                           { converted_rhs }, NULL, &no_attribute);
 
@@ -1863,8 +2024,8 @@ public:
 
         ExceptionStyle exception_style = info.preferredExceptionStyle();
 
-        ConcreteCompilerVariable* called_constant = tryCallattrConstant(
-            emitter, info, var, attr, true, ArgPassSpec(1, 0, 0, 0), { slice }, NULL, &no_attribute, exception_style);
+        CompilerVariable* called_constant = tryCallattrConstant(emitter, info, var, attr, true, ArgPassSpec(1, 0, 0, 0),
+                                                                { slice }, NULL, &no_attribute, exception_style);
 
         if (no_attribute) {
             assert(called_constant->getType() == UNDEF);
@@ -1886,9 +2047,9 @@ public:
         return UNKNOWN->getPystonIter(emitter, info, var);
     }
 
-    ConcreteCompilerVariable* len(IREmitter& emitter, const OpInfo& info, VAR* var) override {
+    CompilerVariable* len(IREmitter& emitter, const OpInfo& info, VAR* var) override {
         static BoxedString* attr = internStringImmortal("__len__");
-        ConcreteCompilerVariable* called_constant
+        CompilerVariable* called_constant
             = tryCallattrConstant(emitter, info, var, attr, true, ArgPassSpec(0, 0, 0, 0), {}, NULL);
         if (called_constant)
             return called_constant;
@@ -1896,13 +2057,13 @@ public:
         return UNKNOWN->len(emitter, info, var);
     }
 
-    ConcreteCompilerVariable* nonzero(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var) override {
+    CompilerVariable* nonzero(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var) override {
         if (cls == None->cls)
             return makeBool(false);
 
         static BoxedString* attr = internStringImmortal("__nonzero__");
         bool no_attribute = false;
-        ConcreteCompilerVariable* called_constant
+        CompilerVariable* called_constant
             = tryCallattrConstant(emitter, info, var, attr, true, ArgPassSpec(0, 0, 0, 0), {}, NULL, &no_attribute);
 
         // TODO: if no_attribute, we could optimize by continuing the dispatch process and trying
@@ -1922,12 +2083,12 @@ public:
         return UNKNOWN->nonzero(emitter, info, var);
     }
 
-    ConcreteCompilerVariable* unaryop(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var,
+    CompilerVariable* unaryop(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var,
                               AST_TYPE::AST_TYPE op_type) override {
         BoxedString* attr = getOpName(op_type);
 
         bool no_attribute = false;
-        ConcreteCompilerVariable* called_constant
+        CompilerVariable* called_constant
             = tryCallattrConstant(emitter, info, var, attr, true, ArgPassSpec(0, 0, 0, 0), {}, NULL, &no_attribute);
 
         if (called_constant && !no_attribute)
@@ -1936,10 +2097,10 @@ public:
         return UNKNOWN->unaryop(emitter, info, var, op_type);
     }
 
-    ConcreteCompilerVariable* hasnext(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var) override {
+    CompilerVariable* hasnext(IREmitter& emitter, const OpInfo& info, ConcreteCompilerVariable* var) override {
         static BoxedString* attr = internStringImmortal("__hasnext__");
 
-        ConcreteCompilerVariable* called_constant
+        CompilerVariable* called_constant
             = tryCallattrConstant(emitter, info, var, attr, true, ArgPassSpec(0, 0, 0, 0), {}, NULL, NULL);
 
         if (called_constant)
@@ -1966,7 +2127,7 @@ public:
     }
 };
 std::unordered_map<BoxedClass*, NormalObjectType*> NormalObjectType::made;
-ConcreteCompilerType* STR, *BOXED_INT, *BOXED_FLOAT, *BOXED_BOOL, *NONE, *ELLIPSIS;
+ConcreteCompilerType* STR, *BOXED_INT, *BOXED_FLOAT, *BOXED_BOOL, *NONE;
 
 class ClosureType : public ConcreteCompilerType {
 public:
@@ -2068,7 +2229,7 @@ public:
         return new ConcreteCompilerVariable(other_type, boxed, true);
     }
 
-    bool canConvertTo(ConcreteCompilerType* other) override { return (other == STR || other == UNKNOWN); }
+    bool canConvertTo(CompilerType* other) override { return (other == STR || other == UNKNOWN); }
 
     CompilerVariable* getattr(IREmitter& emitter, const OpInfo& info, VAR* var, BoxedString* attr,
                               bool cls_only) override {
@@ -2181,7 +2342,7 @@ public:
         return var;
     }
 
-    bool canConvertTo(ConcreteCompilerType* other_type) override {
+    bool canConvertTo(CompilerType* other_type) override {
         return (other_type == UNKNOWN || other_type == BOXED_BOOL || other_type == BOOL);
     }
 
@@ -2266,114 +2427,6 @@ ConcreteCompilerVariable* doIs(IREmitter& emitter, CompilerVariable* lhs, Compil
     return boolFromI1(emitter, cmp);
 }
 
-template <typename T> struct UnboxedVal {
-    T val;
-    ConcreteCompilerVariable* boxed;
-};
-
-template <typename T, typename D> class UnboxedType : public ValuedCompilerType<UnboxedVal<T>*> {
-public:
-    typedef UnboxedVal<T> Unboxed;
-    typedef typename ValuedCompilerType<UnboxedVal<T>*>::VAR VAR;
-
-    void drop(IREmitter& emitter, VAR* var) override final {
-        Unboxed* v = var->getValue();
-        if (v->boxed)
-            v->boxed->decvref(emitter);
-        static_cast<D*>(this)->_drop(emitter, v->val);
-    }
-
-    void grab(IREmitter& emitter, VAR* var) override final { RELEASE_ASSERT(0, ""); }
-
-    CompilerVariable* dup(VAR* var, DupCache& cache) override final {
-        CompilerVariable*& rtn = cache[var];
-
-        if (rtn == NULL) {
-            Unboxed* orig_v = var->getValue();
-
-            T val_duped = static_cast<D*>(this)->_dup(orig_v->val, cache);
-
-            CompilerVariable* box_duped = orig_v->boxed ? orig_v->boxed->dup(cache) : NULL;
-            assert(!box_duped || box_duped->getType() == box_duped->getType()->getBoxType());
-
-            rtn = new VAR(this, new Unboxed{ std::move(val_duped), static_cast<ConcreteCompilerVariable*>(box_duped) },
-                          var->isGrabbed());
-            while (rtn->getVrefs() < var->getVrefs())
-                rtn->incvref();
-        }
-        return rtn;
-    }
-
-    bool canConvertTo(ConcreteCompilerType* other_type) override final {
-        return (other_type == UNKNOWN || other_type == this->getBoxType());
-    }
-
-    ConcreteCompilerVariable* makeConverted(IREmitter& emitter, VAR* var,
-                                            ConcreteCompilerType* other_type) override final {
-        assert(canConvertTo(other_type));
-
-        Unboxed* val = var->getValue();
-        ConcreteCompilerVariable* boxed = val->boxed;
-
-        if (!boxed) {
-            boxed = static_cast<D*>(this)->_makeConverted(emitter, val->val, this->getBoxType());
-            ASSERT(boxed->getType() == this->getBoxType(), "%s %s", boxed->getType()->debugName().c_str(),
-                   this->getBoxType()->debugName().c_str());
-
-            val->boxed = boxed;
-        }
-
-        if (boxed->getType() != other_type) {
-            assert(other_type == UNKNOWN);
-            return boxed->makeConverted(emitter, other_type);
-        }
-
-        boxed->incvref();
-        return boxed;
-    }
-
-    // Serialization strategy is a bit silly for now: we will emit a bool saying whether we emitted the
-    // boxed or unboxed value.  There's no reason that has to be in the serialization though (it could
-    // be in the metadata), and we shouldn't have to pad the smaller version to the size of the larger one.
-    int numFrameArgs() override final {
-        return 1 + std::max(static_cast<D*>(this)->_numFrameArgs(), this->getBoxType()->numFrameArgs());
-    }
-
-    void serializeToFrame(VAR* var, std::vector<llvm::Value*>& stackmap_args) override final {
-        Unboxed* v = var->getValue();
-
-        int total_args = numFrameArgs();
-        int needed_args = stackmap_args.size() + total_args;
-
-        if (v->boxed) {
-            stackmap_args.push_back(getConstantInt(1, g.i64));
-            v->boxed->serializeToFrame(stackmap_args);
-        } else {
-            stackmap_args.push_back(getConstantInt(0, g.i64));
-            static_cast<D*>(this)->_serializeToFrame(v->val, stackmap_args);
-        }
-
-        while (stackmap_args.size() < needed_args)
-            stackmap_args.push_back(getConstantInt(0, g.i64));
-    }
-
-    Box* deserializeFromFrame(const FrameVals& vals) override final {
-        assert(vals.size() == numFrameArgs());
-
-
-        bool is_boxed = vals[0];
-
-        if (is_boxed) {
-            // TODO: inefficient
-            FrameVals sub_vals(vals.begin() + 1, vals.begin() + 1 + this->getBoxType()->numFrameArgs());
-            return this->getBoxType()->deserializeFromFrame(sub_vals);
-        } else {
-            FrameVals sub_vals(vals.begin() + 1, vals.begin() + 1 + static_cast<D*>(this)->_numFrameArgs());
-            return static_cast<D*>(this)->_deserializeFromFrame(sub_vals);
-        }
-    }
-};
-
 ConcreteCompilerType* BOXED_TUPLE;
 class TupleType : public UnboxedType<const std::vector<CompilerVariable*>, TupleType> {
 private:
@@ -2395,11 +2448,11 @@ private:
 public:
     typedef const std::vector<CompilerVariable*> VEC;
 
-    void assertMatches(Unboxed* v) override {
-        assert(v->val.size() == elt_types.size());
+    void _assertMatches(const VEC& v) {
+        assert(v.size() == elt_types.size());
 
-        for (int i = 0; i < v->val.size(); i++) {
-            assert((v->val)[i]->getType() == elt_types[i]);
+        for (int i = 0; i < v.size(); i++) {
+            assert(v[i]->getType() == elt_types[i]);
         }
     }
 
@@ -2456,17 +2509,16 @@ public:
 
     ConcreteCompilerType* getBoxType() override { return BOXED_TUPLE; }
 
-    ConcreteCompilerType* getConcreteType() override { return BOXED_TUPLE; }
-
     static TupleType* make(const std::vector<CompilerType*>& elt_types) { return new TupleType(elt_types); }
 
     CompilerVariable* getitem(IREmitter& emitter, const OpInfo& info, VAR* var, CompilerVariable* slice) override {
+        assert(slice->getType() != UNBOXED_INT);
         if (slice->getType() == INT) {
-            llvm::Value* v = static_cast<ConcreteCompilerVariable*>(slice)->getValue();
+            llvm::Value* v = IntType::extractInt(slice);
             assert(v->getType() == g.i64);
             if (llvm::ConstantInt* ci = llvm::dyn_cast<llvm::ConstantInt>(v)) {
                 int64_t i = ci->getSExtValue();
-                Unboxed* v = var->getValue();
+                auto v = var->getValue();
                 const VEC* elts = &v->val;
                 if (i >= 0 && i < elts->size()) {
                     CompilerVariable* rtn = (*elts)[i];
@@ -2500,8 +2552,8 @@ public:
         return rtn;
     }
 
-    ConcreteCompilerVariable* len(IREmitter& emitter, const OpInfo& info, VAR* var) override {
-        return new ConcreteCompilerVariable(INT, getConstantInt(var->getValue()->val.size(), g.i64), true);
+    CompilerVariable* len(IREmitter& emitter, const OpInfo& info, VAR* var) override {
+        return makeInt(var->getValue()->val.size());
     }
 
     CompilerType* getattrType(BoxedString* attr, bool cls_only) override {
@@ -2539,9 +2591,9 @@ public:
 
             {
                 CompilerVariable* eq = converted_lhs->binexp(emitter, info, e, AST_TYPE::Eq, Compare);
-                ConcreteCompilerVariable* eq_nonzero = eq->nonzero(emitter, info);
+                CompilerVariable* eq_nonzero = eq->nonzero(emitter, info);
                 assert(eq_nonzero->getType() == BOOL);
-                llvm::Value* raw = i1FromBool(emitter, eq_nonzero);
+                llvm::Value* raw = i1FromBool(emitter, static_cast<ConcreteCompilerVariable*>(eq_nonzero));
 
                 phi_incoming.push_back(std::make_pair(emitter.currentBasicBlock(), getConstantInt(1, g.i1)));
                 llvm::BasicBlock* new_bb = emitter.createBasicBlock();
@@ -2640,7 +2692,7 @@ CompilerVariable* makeTuple(const std::vector<CompilerVariable*>& elts) {
     }
     TupleType* type = TupleType::make(elt_types);
 
-    auto alloc_var = new TupleType::Unboxed({ elts, NULL });
+    auto alloc_var = std::make_shared<TupleType::Unboxed>(elts, nullptr);
     return new TupleType::VAR(type, alloc_var, true);
 }
 
@@ -2715,7 +2767,7 @@ public:
 
     CompilerType* getattrType(BoxedString* attr, bool cls_only) override { return UNDEF; }
 
-    bool canConvertTo(ConcreteCompilerType* other_type) override { return true; }
+    bool canConvertTo(CompilerType* other_type) override { return true; }
 
     BoxedClass* guaranteedClass() override { return NULL; }
 

src/codegen/compvars.h

@@ -47,7 +47,7 @@ public:
     virtual std::string debugName() = 0;
     virtual ConcreteCompilerType* getConcreteType() = 0;
     virtual ConcreteCompilerType* getBoxType() = 0;
-    virtual bool canConvertTo(ConcreteCompilerType* other_type) = 0;
+    virtual bool canConvertTo(CompilerType* other_type) = 0;
     virtual CompilerType* getattrType(BoxedString* attr, bool cls_only) = 0;
     virtual CompilerType* getPystonIterType();
     virtual Result hasattr(BoxedString* attr);
@@ -58,6 +58,13 @@ public:
     virtual Box* deserializeFromFrame(const FrameVals& vals) = 0;
     virtual int numFrameArgs() = 0;
     virtual std::vector<CompilerType*> unpackTypes(int num_into);
+
+    // Some types are not "usable" even if they are "concrete".  Concrete means that it's possible to
+    // represent the value as an llvm::Value*; usable means that we are allowed to use it as a variable's
+    // type.  Some concrete types are not usable; for example unboxed ints are concrete (can be represented
+    // as an i64) but are not usable, since we need to use the form that remembers what it gets boxed to.
+    virtual CompilerType* getUsableType() { return this; }
+    bool isUsable() { return this == getUsableType(); }
 };
 
 typedef std::unordered_map<CompilerVariable*, CompilerVariable*> DupCache;
@@ -94,7 +101,7 @@ public:
         printf("grab not defined for %s\n", debugName().c_str());
         abort();
     }
-    bool canConvertTo(ConcreteCompilerType* other_type) override {
+    bool canConvertTo(CompilerType* other_type) override {
         printf("canConvertTo not defined for %s\n", debugName().c_str());
         abort();
     }
@@ -102,13 +109,12 @@ public:
         printf("makeConverted not defined for %s\n", debugName().c_str());
         abort();
     }
-    virtual ConcreteCompilerVariable* nonzero(IREmitter& emitter, const OpInfo& info, VAR* var) {
+    virtual CompilerVariable* nonzero(IREmitter& emitter, const OpInfo& info, VAR* var) {
         printf("nonzero not defined for %s\n", debugName().c_str());
         abort();
     }
-    virtual ConcreteCompilerVariable* unaryop(IREmitter& emitter, const OpInfo& info, VAR* var,
-                                              AST_TYPE::AST_TYPE op_type);
-    virtual ConcreteCompilerVariable* hasnext(IREmitter& emitter, const OpInfo& info, VAR* var) {
+    virtual CompilerVariable* unaryop(IREmitter& emitter, const OpInfo& info, VAR* var, AST_TYPE::AST_TYPE op_type);
+    virtual CompilerVariable* hasnext(IREmitter& emitter, const OpInfo& info, VAR* var) {
         printf("hasnext not defined for %s\n", debugName().c_str());
         abort();
     }
@@ -139,7 +145,7 @@ public:
         printf("call not defined for %s\n", debugName().c_str());
         abort();
     }
-    virtual ConcreteCompilerVariable* len(IREmitter& emitter, const OpInfo& info, VAR* var) {
+    virtual CompilerVariable* len(IREmitter& emitter, const OpInfo& info, VAR* var) {
         printf("len not defined for %s\n", debugName().c_str());
         abort();
     }
@@ -202,7 +208,7 @@ public:
 
     CompilerVariable* dup(ConcreteCompilerVariable* v, DupCache& cache) override;
     ConcreteCompilerType* getConcreteType() override { return this; }
-    bool canConvertTo(ConcreteCompilerType* other_type) override { return other_type == this || other_type == UNKNOWN; }
+    bool canConvertTo(CompilerType* other_type) override { return other_type == this || other_type == UNKNOWN; }
     ConcreteCompilerVariable* makeConverted(IREmitter& emitter, ConcreteCompilerVariable* var,
                                             ConcreteCompilerType* other_type) override;
     void serializeToFrame(VAR* var, std::vector<llvm::Value*>& stackmap_args) override;
@@ -261,14 +267,14 @@ public:
     virtual CompilerType* getType() = 0;
     virtual ConcreteCompilerType* getConcreteType() = 0;
     virtual ConcreteCompilerType* getBoxType() = 0;
-    virtual bool canConvertTo(ConcreteCompilerType* other_type) = 0;
+    virtual bool canConvertTo(CompilerType* other_type) = 0;
     virtual ConcreteCompilerVariable* makeConverted(IREmitter& emitter, ConcreteCompilerType* other_type) = 0;
     virtual llvm::Value* makeClassCheck(IREmitter& emitter, BoxedClass* cls) = 0;
     virtual BoxedClass* guaranteedClass() = 0;
 
-    virtual ConcreteCompilerVariable* nonzero(IREmitter& emitter, const OpInfo& info) = 0;
-    virtual ConcreteCompilerVariable* unaryop(IREmitter& emitter, const OpInfo& info, AST_TYPE::AST_TYPE op_type) = 0;
-    virtual ConcreteCompilerVariable* hasnext(IREmitter& emitter, const OpInfo& info) = 0;
+    virtual CompilerVariable* nonzero(IREmitter& emitter, const OpInfo& info) = 0;
+    virtual CompilerVariable* unaryop(IREmitter& emitter, const OpInfo& info, AST_TYPE::AST_TYPE op_type) = 0;
+    virtual CompilerVariable* hasnext(IREmitter& emitter, const OpInfo& info) = 0;
     virtual CompilerVariable* getattr(IREmitter& emitter, const OpInfo& info, BoxedString* attr, bool cls_only) = 0;
     virtual void setattr(IREmitter& emitter, const OpInfo& info, BoxedString* attr, CompilerVariable* v) = 0;
     virtual void delattr(IREmitter& emitter, const OpInfo& info, BoxedString* attr) = 0;
@@ -278,7 +284,7 @@ public:
     virtual CompilerVariable* call(IREmitter& emitter, const OpInfo& info, struct ArgPassSpec argspec,
                                    const std::vector<CompilerVariable*>& args,
                                    const std::vector<BoxedString*>* keyword_names) = 0;
-    virtual ConcreteCompilerVariable* len(IREmitter& emitter, const OpInfo& info) = 0;
+    virtual CompilerVariable* len(IREmitter& emitter, const OpInfo& info) = 0;
     virtual CompilerVariable* getitem(IREmitter& emitter, const OpInfo& info, CompilerVariable*) = 0;
     virtual CompilerVariable* getPystonIter(IREmitter& emitter, const OpInfo& info) = 0;
     virtual CompilerVariable* binexp(IREmitter& emitter, const OpInfo& info, CompilerVariable* rhs,
@@ -330,19 +336,19 @@ public:
         return rtn;
     }
 
-    bool canConvertTo(ConcreteCompilerType* other_type) override { return type->canConvertTo(other_type); }
+    bool canConvertTo(CompilerType* other_type) override { return type->canConvertTo(other_type); }
     ConcreteCompilerVariable* makeConverted(IREmitter& emitter, ConcreteCompilerType* other_type) override {
         ConcreteCompilerVariable* rtn = type->makeConverted(emitter, this, other_type);
         ASSERT(rtn->getType() == other_type, "%s", type->debugName().c_str());
         return rtn;
     }
-    ConcreteCompilerVariable* nonzero(IREmitter& emitter, const OpInfo& info) override {
+    CompilerVariable* nonzero(IREmitter& emitter, const OpInfo& info) override {
         return type->nonzero(emitter, info, this);
     }
-    ConcreteCompilerVariable* unaryop(IREmitter& emitter, const OpInfo& info, AST_TYPE::AST_TYPE op_type) override {
+    CompilerVariable* unaryop(IREmitter& emitter, const OpInfo& info, AST_TYPE::AST_TYPE op_type) override {
         return type->unaryop(emitter, info, this, op_type);
     }
-    ConcreteCompilerVariable* hasnext(IREmitter& emitter, const OpInfo& info) override {
+    CompilerVariable* hasnext(IREmitter& emitter, const OpInfo& info) override {
         return type->hasnext(emitter, info, this);
     }
     CompilerVariable* getattr(IREmitter& emitter, const OpInfo& info, BoxedString* attr, bool cls_only) override {
@@ -366,9 +372,7 @@ public:
                            const std::vector<BoxedString*>* keyword_names) override {
         return type->call(emitter, info, this, argspec, args, keyword_names);
     }
-    ConcreteCompilerVariable* len(IREmitter& emitter, const OpInfo& info) override {
-        return type->len(emitter, info, this);
-    }
+    CompilerVariable* len(IREmitter& emitter, const OpInfo& info) override { return type->len(emitter, info, this); }
     CompilerVariable* getitem(IREmitter& emitter, const OpInfo& info, CompilerVariable* slice) override {
         return type->getitem(emitter, info, this, slice);
     }
@@ -407,9 +411,20 @@ public:
 // Emit the test for whether one variable 'is' another one.
 ConcreteCompilerVariable* doIs(IREmitter& emitter, CompilerVariable* lhs, CompilerVariable* rhs, bool negate);
 
+// These functions all return an INT variable, from either an unboxed representation (makeInt) or
+// a boxed representation (makeUnboxedInt)
+CompilerVariable* makeInt(int64_t);
+CompilerVariable* makeInt(llvm::Value*);
+CompilerVariable* makeUnboxedInt(IREmitter&, ConcreteCompilerVariable*);
+CompilerVariable* makeUnboxedInt(IREmitter&, llvm::Value*);
+
+// Same for floats:
+CompilerVariable* makeFloat(llvm::Value*);
+CompilerVariable* makeFloat(double);
+CompilerVariable* makeUnboxedFloat(IREmitter&, ConcreteCompilerVariable*);
+CompilerVariable* makeUnboxedFloat(IREmitter&, llvm::Value*);
+
 ConcreteCompilerVariable* makeBool(bool);
-ConcreteCompilerVariable* makeInt(int64_t);
-ConcreteCompilerVariable* makeFloat(double);
 ConcreteCompilerVariable* makeLong(Box*);
 ConcreteCompilerVariable* makePureImaginary(Box*);
 CompilerVariable* makeStr(BoxedString*);
@@ -447,7 +462,7 @@ CompilerVariable* _ValuedCompilerType<V>::contains(IREmitter& emitter, const OpI
 }
 
 template <typename V>
-ConcreteCompilerVariable* _ValuedCompilerType<V>::unaryop(IREmitter& emitter, const OpInfo& info, VAR* var,
+CompilerVariable* _ValuedCompilerType<V>::unaryop(IREmitter& emitter, const OpInfo& info, VAR* var,
                                                   AST_TYPE::AST_TYPE op_type) {
     ConcreteCompilerVariable* converted = makeConverted(emitter, var, getBoxType());
     auto r = UNKNOWN->unaryop(emitter, info, converted, op_type);

src/codegen/irgen/irgenerator.cpp

@@ -799,7 +799,7 @@ private:
                 assert(node->args.size() == 1);
                 CompilerVariable* obj = evalExpr(node->args[0], unw_info);
 
-                ConcreteCompilerVariable* rtn = obj->nonzero(emitter, getOpInfoForNode(node, unw_info));
+                CompilerVariable* rtn = obj->nonzero(emitter, getOpInfoForNode(node, unw_info));
                 obj->decvref(emitter);
                 return rtn;
             }
@@ -807,7 +807,7 @@ private:
                 assert(node->args.size() == 1);
                 CompilerVariable* obj = evalExpr(node->args[0], unw_info);
 
-                ConcreteCompilerVariable* rtn = obj->hasnext(emitter, getOpInfoForNode(node, unw_info));
+                CompilerVariable* rtn = obj->hasnext(emitter, getOpInfoForNode(node, unw_info));
                 obj->decvref(emitter);
                 return rtn;
             }
@@ -1348,18 +1348,18 @@ private:
         CompilerVariable* operand = evalExpr(node->operand, unw_info);
 
         if (node->op_type == AST_TYPE::Not) {
-            ConcreteCompilerVariable* rtn = operand->nonzero(emitter, getOpInfoForNode(node, unw_info));
+            CompilerVariable* rtn = operand->nonzero(emitter, getOpInfoForNode(node, unw_info));
             operand->decvref(emitter);
 
             assert(rtn->getType() == BOOL);
-            llvm::Value* v = i1FromBool(emitter, rtn);
+            llvm::Value* v = i1FromBool(emitter, static_cast<ConcreteCompilerVariable*>(rtn));
             assert(v->getType() == g.i1);
 
             llvm::Value* negated = emitter.getBuilder()->CreateNot(v);
             rtn->decvref(emitter);
             return boolFromI1(emitter, negated);
         } else {
-            ConcreteCompilerVariable* rtn = operand->unaryop(emitter, getOpInfoForNode(node, unw_info), node->op_type);
+            CompilerVariable* rtn = operand->unaryop(emitter, getOpInfoForNode(node, unw_info), node->op_type);
             operand->decvref(emitter);
             return rtn;
         }
@@ -1517,19 +1517,13 @@ private:
     }
 
     // Note: the behavior of this function must match type_analysis.cpp:unboxedType()
-    ConcreteCompilerVariable* unboxVar(ConcreteCompilerType* t, llvm::Value* v, bool grabbed) {
-#if ENABLE_UNBOXED_VALUES
+    CompilerVariable* unboxVar(ConcreteCompilerType* t, llvm::Value* v, bool grabbed) {
         if (t == BOXED_INT) {
-            llvm::Value* unboxed = emitter.getBuilder()->CreateCall(g.funcs.unboxInt, v);
-            ConcreteCompilerVariable* rtn = new ConcreteCompilerVariable(INT, unboxed, true);
-            return rtn;
+            return makeUnboxedInt(emitter, v);
         }
         if (t == BOXED_FLOAT) {
-            llvm::Value* unboxed = emitter.getBuilder()->CreateCall(g.funcs.unboxFloat, v);
-            ConcreteCompilerVariable* rtn = new ConcreteCompilerVariable(FLOAT, unboxed, true);
-            return rtn;
+            return makeUnboxedFloat(emitter, v);
         }
-#endif
         if (t == BOXED_BOOL) {
             llvm::Value* unboxed = emitter.getBuilder()->CreateCall(g.funcs.unboxBool, v);
             return boolFromI1(emitter, unboxed);
@@ -1548,7 +1542,7 @@ private:
 
             ConcreteCompilerType* speculated_type = typeFromClass(speculated_class);
             if (VERBOSITY("irgen") >= 2) {
-                printf("Speculating that %s is actually %s, at ", rtn->getConcreteType()->debugName().c_str(),
+                printf("Speculating that %s is actually %s, at ", rtn->getType()->debugName().c_str(),
                        speculated_type->debugName().c_str());
                 fflush(stdout);
                 print_ast(node);
@@ -1580,6 +1574,7 @@ private:
         }
 
         assert(rtn);
+        assert(rtn->getType()->isUsable());
 
         return rtn;
     }
@@ -1728,6 +1723,7 @@ private:
     void _doSet(InternedString name, CompilerVariable* val, const UnwindInfo& unw_info) {
         assert(name.s() != "None");
         assert(name.s() != FRAME_INFO_PTR_NAME);
+        assert(val->getType()->isUsable());
 
         auto scope_info = irstate->getScopeInfo();
         ScopeInfo::VarScopeType vst = scope_info->getScopeTypeOfName(name);
@@ -2210,11 +2206,9 @@ private:
             ConcreteCompilerVariable* var = p.second->makeConverted(emitter, p.second->getConcreteType());
             converted_args.push_back(var);
 
-#if ENABLE_UNBOXED_VALUES
-            assert(var->getType() != BOXED_INT && "should probably unbox it, but why is it boxed in the first place?");
+            assert(var->getType() != BOXED_INT);
             assert(var->getType() != BOXED_FLOAT
                    && "should probably unbox it, but why is it boxed in the first place?");
-#endif
 
             // This line can never get hit right now for the same reason that the variables must already be
             // concrete,
@@ -2438,13 +2432,13 @@ private:
 
     void loadArgument(InternedString name, ConcreteCompilerType* t, llvm::Value* v, const UnwindInfo& unw_info) {
         assert(name.s() != FRAME_INFO_PTR_NAME);
-        ConcreteCompilerVariable* var = unboxVar(t, v, false);
+        CompilerVariable* var = unboxVar(t, v, false);
         _doSet(name, var, unw_info);
         var->decvref(emitter);
     }
 
     void loadArgument(AST_expr* name, ConcreteCompilerType* t, llvm::Value* v, const UnwindInfo& unw_info) {
-        ConcreteCompilerVariable* var = unboxVar(t, v, false);
+        CompilerVariable* var = unboxVar(t, v, false);
         _doSet(name, var, unw_info);
         var->decvref(emitter);
     }
@@ -2467,6 +2461,7 @@ private:
         std::map<InternedString, CompilerVariable*> sorted_symbol_table(symbol_table.begin(), symbol_table.end());
         for (const auto& p : sorted_symbol_table) {
             assert(p.first.s() != FRAME_INFO_PTR_NAME);
+            assert(p.second->getType()->isUsable());
             if (allowableFakeEndingSymbol(p.first))
                 continue;
 
@@ -2483,6 +2478,7 @@ private:
             } else if (irstate->getPhis()->isRequiredAfter(p.first, myblock)) {
                 assert(scope_info->getScopeTypeOfName(p.first) != ScopeInfo::VarScopeType::GLOBAL);
                 ConcreteCompilerType* phi_type = types->getTypeAtBlockEnd(p.first, myblock);
+                assert(phi_type->isUsable());
                 // printf("Converting %s from %s to %s\n", p.first.c_str(),
                 // p.second->getType()->debugName().c_str(), phi_type->debugName().c_str());
                 // printf("have to convert %s from %s to %s\n", p.first.c_str(),
@@ -2533,6 +2529,7 @@ private:
             } else {
                 // printf("no st entry, setting undefined\n");
                 ConcreteCompilerType* phi_type = types->getTypeAtBlockEnd(*it, myblock);
+                assert(phi_type->isUsable());
                 cur = new ConcreteCompilerVariable(phi_type, llvm::UndefValue::get(phi_type->llvmType()), true);
                 _setFake(defined_name, makeBool(0));
             }
@@ -2553,7 +2550,7 @@ public:
             pp->addFrameVar(PASSED_GLOBALS_NAME, UNKNOWN);
         }
 
-        assert(INT->llvmType() == g.i64);
+        assert(UNBOXED_INT->llvmType() == g.i64);
         if (ENABLE_JIT_OBJECT_CACHE) {
             llvm::Value* v;
             if (current_stmt)
@@ -2565,7 +2562,7 @@ public:
             stackmap_args.push_back(getConstantInt((uint64_t)current_stmt, g.i64));
         }
 
-        pp->addFrameVar("!current_stmt", INT);
+        pp->addFrameVar("!current_stmt", UNBOXED_INT);
 
         if (ENABLE_FRAME_INTROSPECTION) {
             // TODO: don't need to use a sorted symbol table if we're explicitly recording the names!
@@ -2600,6 +2597,10 @@ public:
         // This should have been consumed:
         assert(incoming_exc_state.empty());
 
+        for (auto&& p : symbol_table) {
+            ASSERT(p.second->getType()->isUsable(), "%s", p.first.c_str());
+        }
+
         if (myblock->successors.size() == 0) {
             for (auto& p : *st) {
                 p.second->decvref(emitter);
@@ -2645,6 +2646,7 @@ public:
                 } else {
                     ending_type = types->getTypeAtBlockEnd(it->first, myblock);
                 }
+                assert(ending_type->isUsable());
                 //(*phi_st)[it->first] = it->second->makeConverted(emitter, it->second->getConcreteType());
                 // printf("%s %p %d\n", it->first.c_str(), it->second, it->second->getVrefs());
                 (*phi_st)[it->first] = it->second->split(emitter)->makeConverted(emitter, ending_type);
@@ -2661,10 +2663,9 @@ public:
         assert(name.s() != FRAME_INFO_PTR_NAME);
         ASSERT(irstate->getScopeInfo()->getScopeTypeOfName(name) != ScopeInfo::VarScopeType::GLOBAL, "%s",
                name.c_str());
-#if ENABLE_UNBOXED_VALUES
-        assert(var->getType() != BOXED_INT);
-        assert(var->getType() != BOXED_FLOAT);
-#endif
+
+        ASSERT(var->getType()->isUsable(), "%s", name.c_str());
+
         CompilerVariable*& cur = symbol_table[name];
         assert(cur == NULL);
         cur = var;
@@ -2675,7 +2676,9 @@ public:
         DupCache cache;
         for (SymbolTable::iterator it = st->begin(); it != st->end(); ++it) {
             // printf("Copying in %s: %p, %d\n", it->first.c_str(), it->second, it->second->getVrefs());
+            // printf("Copying in %s, a %s\n", it->first.c_str(), it->second->getType()->debugName().c_str());
             symbol_table[it->first] = it->second->dup(cache);
+            assert(symbol_table[it->first]->getType()->isUsable());
             // printf("got: %p, %d\n", symbol_table[it->first], symbol_table[it->first]->getVrefs());
         }
     }

src/core/options.h

@@ -51,12 +51,6 @@ extern bool ENABLE_ICS, ENABLE_ICGENERICS, ENABLE_ICGETITEMS, ENABLE_ICSETITEMS,
 extern bool BOOLS_AS_I64;
 
 #define ENABLE_SAMPLING_PROFILER 0
-
-// Our current implementation of unbox values has some minor compatibility issues, where it can
-// change the apparent id() / is-equality of a boxed value (by inserting extra unbox+box pairs).
-// I think it can be rescued (we need the unboxed compilertype to remember the boxed value),
-// but for now it's just turned off with this flag.
-#define ENABLE_UNBOXED_VALUES 0
 }
 }
 

src/core/types.h

@@ -93,10 +93,10 @@ template <class V> class ValuedCompilerType;
 typedef ValuedCompilerType<llvm::Value*> ConcreteCompilerType;
 ConcreteCompilerType* typeFromClass(BoxedClass*);
 
-extern ConcreteCompilerType* INT, *BOXED_INT, *LONG, *FLOAT, *BOXED_FLOAT, *UNKNOWN, *BOOL, *STR, *NONE, *LIST, *SLICE,*ELLIPSIS,
-    *MODULE, *DICT, *BOOL, *BOXED_BOOL, *BOXED_TUPLE, *SET, *FROZENSET, *CLOSURE, *GENERATOR, *BOXED_COMPLEX,
-    *FRAME_INFO;
-extern CompilerType* UNDEF;
+extern ConcreteCompilerType* UNBOXED_INT, *BOXED_INT, *LONG, *UNBOXED_FLOAT, *BOXED_FLOAT, *UNKNOWN, *BOOL, *STR, *NONE,
+    *LIST, *SLICE, *MODULE, *DICT, *BOOL, *BOXED_BOOL, *BOXED_TUPLE, *SET, *FROZENSET, *CLOSURE, *GENERATOR,
+    *BOXED_COMPLEX, *FRAME_INFO;
+extern CompilerType* UNDEF, *INT, *FLOAT;
 
 class CompilerVariable;
 template <class V> class ValuedCompilerVariable;

src/runtime/builtin_modules/builtins.cpp

@@ -1524,12 +1524,16 @@ Box* builtinFormat(Box* value, Box* format_spec) {
     return res;
 }
 
+extern "C" {
+BoxedClass* ellipsis_cls;
+}
+
 void setupBuiltins() {
     builtins_module = createModule(boxString("__builtin__"), NULL,
                                    "Built-in functions, exceptions, and other objects.\n\nNoteworthy: None is "
                                    "the `nil' object; Ellipsis represents `...' in slices.");
 
-    BoxedClass* ellipsis_cls = BoxedClass::create(type_cls, object_cls, NULL, 0, 0, sizeof(Box), false, "ellipsis");
+    ellipsis_cls = BoxedClass::create(type_cls, object_cls, NULL, 0, 0, sizeof(Box), false, "ellipsis");
     ellipsis_cls->giveAttr("__repr__", new BoxedFunction(boxRTFunction((void*)ellipsisRepr, STR, 1)));
     Ellipsis = new (ellipsis_cls) Box();
     assert(Ellipsis->cls);

src/runtime/inline/xrange.cpp

@@ -270,7 +270,7 @@ void setupXrange() {
         "__iter__", new BoxedFunction(boxRTFunction((void*)xrangeIterIter, typeFromClass(xrange_iterator_cls), 1)));
     xrange_iterator_cls->giveAttr("__hasnext__", new BoxedFunction(hasnext));
 
-    CLFunction* next = boxRTFunction((void*)BoxedXrangeIterator::xrangeIteratorNextUnboxed, INT, 1);
+    CLFunction* next = boxRTFunction((void*)BoxedXrangeIterator::xrangeIteratorNextUnboxed, UNBOXED_INT, 1);
     addRTFunction(next, (void*)BoxedXrangeIterator::xrangeIteratorNext, BOXED_INT);
     xrange_iterator_cls->giveAttr("next", new BoxedFunction(next));
 

test/tests/int_ids.py

@@ -42,6 +42,14 @@ def f4(a, b):
 for i in xrange(11000):
     f4(1000, 1000)
 
+def f6():
+    for i in xrange(11000):
+        a = b = 1000
+        if True:
+            pass
+        f4(a, b)
+f6()
+
 
 # This applies to other data types as well.  (maybe should call this test file something else)
 def ident(x):
@@ -49,7 +57,7 @@ def ident(x):
 
 def f5():
     t = (1, 2, 3)
-    print ident(t) is t
+    assert ident(t) is t
 
 for i in xrange(10):
     f5()