A bunch of small fixes

src/asm_writing/rewriter.cpp

@@ -548,7 +548,7 @@ void Rewriter::_incref(RewriterVar* var, int num_refs) {
 
     if (var->isConstant() && !Rewriter::isLargeConstant(var->constant_value)) {
         for (int i = 0; i < num_refs; i++) {
-            assembler->incq(assembler::Immediate(var->constant_value));
+            assembler->incq(assembler::Immediate((uint64_t)var->constant_value + offsetof(Box, ob_refcnt)));
         }
     } else {
         auto reg = var->getInReg();

src/codegen/irgen/irgenerator.cpp

@@ -1945,6 +1945,8 @@ private:
                 if (prev) {
                     auto load = emitter.getBuilder()->CreateLoad(gep);
                     emitter.setType(load, RefType::OWNED);
+                    if (maybe_was_undefined)
+                        emitter.setNullable(load, true);
                 }
                 llvm::Value* v = val->makeConverted(emitter, UNKNOWN)->getValue();
                 auto store = emitter.getBuilder()->CreateStore(v, gep);

src/jit.cpp

@@ -443,6 +443,7 @@ static int main(int argc, char** argv) noexcept {
                 Box* module = PyImport_ImportModule("site");
                 if (!module)
                     throwCAPIException();
+                Py_DECREF(module);
             } catch (ExcInfo e) {
                 e.printExcAndTraceback();
                 e.clear();

src/runtime/frame.cpp

@@ -222,8 +222,7 @@ BORROWED(Box*) getFrame(int depth) {
 
 void frameInvalidateBack(BoxedFrame* frame) {
     RELEASE_ASSERT(!frame->hasExited(), "should not happen");
-    assert(!frame->_back && "have to decref it");
-    frame->_back = NULL;
+    Py_CLEAR(frame->_back);
 }
 
 extern "C" void initFrame(FrameInfo* frame_info) {

test/tests/float_precision.py

@@ -5,7 +5,7 @@ def smallest():
         n = n * 0.99
     return n
 
-for i in xrange(1000):
+for i in xrange(100):
     print smallest()
 
 def test(x):