diff -r c4e8751ce637 Modules/_collectionsmodule.c
--- a/Modules/_collectionsmodule.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Modules/_collectionsmodule.c	Thu Dec 24 10:58:52 2015 +0200
@@ -1222,7 +1222,6 @@ deque_del_item(dequeobject *deque, Py_ss
 static int
 deque_ass_item(dequeobject *deque, Py_ssize_t i, PyObject *v)
 {
-    PyObject *old_value;
     block *b;
     Py_ssize_t n, len=Py_SIZE(deque), halflen=(len+1)>>1, index=i;
 
@@ -1249,9 +1248,7 @@ deque_ass_item(dequeobject *deque, Py_ss
             b = b->leftlink;
     }
     Py_INCREF(v);
-    old_value = b->data[i];
-    b->data[i] = v;
-    Py_DECREF(old_value);
+    Py_SETREF(b->data[i], v);
     return 0;
 }
 
diff -r c4e8751ce637 Modules/_ctypes/_ctypes.c
--- a/Modules/_ctypes/_ctypes.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Modules/_ctypes/_ctypes.c	Thu Dec 24 10:58:52 2015 +0200
@@ -2983,10 +2983,9 @@ PyCFuncPtr_set_restype(PyCFuncPtrObject 
                         "restype must be a type, a callable, or None");
         return -1;
     }
-    Py_XDECREF(self->checker);
     Py_INCREF(ob);
     Py_SETREF(self->restype, ob);
-    self->checker = PyObject_GetAttrString(ob, "_check_retval_");
+    Py_SETREF(self->checker, PyObject_GetAttrString(ob, "_check_retval_"));
     if (self->checker == NULL)
         PyErr_Clear();
     return 0;
@@ -5124,23 +5123,22 @@ int
 comerror_init(PyObject *self, PyObject *args, PyObject *kwds)
 {
     PyObject *hresult, *text, *details;
-    PyBaseExceptionObject *bself;
     PyObject *a;
     int status;
 
     if (!_PyArg_NoKeywords(Py_TYPE(self)->tp_name, kwds))
-    return -1;
+        return -1;
 
     if (!PyArg_ParseTuple(args, "OOO:COMError", &hresult, &text, &details))
         return -1;
 
     a = PySequence_GetSlice(args, 1, PySequence_Size(args));
     if (!a)
-    return -1;
+        return -1;
     status = PyObject_SetAttrString(self, "args", a);
     Py_DECREF(a);
     if (status < 0)
-    return -1;
+        return -1;
 
     if (PyObject_SetAttrString(self, "hresult", hresult) < 0)
         return -1;
@@ -5151,9 +5149,8 @@ comerror_init(PyObject *self, PyObject *
     if (PyObject_SetAttrString(self, "details", details) < 0)
         return -1;
 
-    bself = (PyBaseExceptionObject *)self;
     Py_INCREF(args);
-    Py_SETREF(bself->args, args);
+    Py_SETREF((PyBaseExceptionObject *)self->args, args);
 
     return 0;
 }
diff -r c4e8751ce637 Modules/_elementtree.c
--- a/Modules/_elementtree.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Modules/_elementtree.c	Thu Dec 24 10:58:52 2015 +0200
@@ -1961,8 +1961,7 @@ element_tag_setter(ElementObject *self, 
 {
     _VALIDATE_ATTR_VALUE(value);
     Py_INCREF(value);
-    Py_DECREF(self->tag);
-    self->tag = value;
+    Py_SETREF(self->tag, value);
     return 0;
 }
 
@@ -1995,8 +1994,7 @@ element_attrib_setter(ElementObject *sel
             return -1;
     }
     Py_INCREF(value);
-    Py_DECREF(self->extra->attrib);
-    self->extra->attrib = value;
+    Py_SETREF(self->extra->attrib, value);
     return 0;
 }
 
@@ -2342,13 +2340,9 @@ static int
                                        PyObject *element_factory)
 /*[clinic end generated code: output=91cfa7558970ee96 input=1b424eeefc35249c]*/
 {
-    PyObject *tmp;
-
     if (element_factory) {
         Py_INCREF(element_factory);
-        tmp = self->element_factory;
-        self->element_factory = element_factory;
-        Py_XDECREF(tmp);
+        Py_SETREF(self->element_factory, element_factory);
     }
 
     return 0;
@@ -2533,13 +2527,10 @@ treebuilder_handle_start(TreeBuilderObje
     }
     self->index++;
 
-    Py_DECREF(this);
     Py_INCREF(node);
-    self->this = node;
-
-    Py_DECREF(self->last);
     Py_INCREF(node);
-    self->last = node;
+    Py_SETREF(self->this, node);
+    Py_SETREF(self->last, node);
 
     if (treebuilder_append_event(self, self->start_event_obj, node) < 0)
         goto error;
@@ -2617,9 +2608,7 @@ treebuilder_handle_end(TreeBuilderObject
     item = PyList_GET_ITEM(self->stack, self->index);
     Py_INCREF(item);
 
-    Py_DECREF(self->last);
-
-    self->last = self->this;
+    Py_SETREF(self->last, self->this);
     self->this = item;
 
     if (treebuilder_append_event(self, self->end_event_obj, self->last) < 0)
diff -r c4e8751ce637 Modules/_io/bytesio.c
--- a/Modules/_io/bytesio.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Modules/_io/bytesio.c	Thu Dec 24 10:58:52 2015 +0200
@@ -87,7 +87,7 @@ scan_eol(bytesio *self, Py_ssize_t len)
 static int
 unshare_buffer(bytesio *self, size_t size)
 {
-    PyObject *new_buf, *old_buf;
+    PyObject *new_buf;
     assert(SHARED_BUF(self));
     assert(self->exports == 0);
     assert(size >= (size_t)self->string_size);
@@ -96,9 +96,7 @@ unshare_buffer(bytesio *self, size_t siz
         return -1;
     memcpy(PyBytes_AS_STRING(new_buf), PyBytes_AS_STRING(self->buf),
            self->string_size);
-    old_buf = self->buf;
-    self->buf = new_buf;
-    Py_DECREF(old_buf);
+    Py_SETREF(self->buf, new_buf);
     return 0;
 }
 
diff -r c4e8751ce637 Modules/_sqlite/connection.c
--- a/Modules/_sqlite/connection.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Modules/_sqlite/connection.c	Thu Dec 24 10:58:52 2015 +0200
@@ -204,8 +204,8 @@ void pysqlite_flush_statement_cache(pysq
         node = node->next;
     }
 
-    Py_SETREF(self->statement_cache,
-              (pysqlite_Cache *)PyObject_CallFunction((PyObject *)&pysqlite_CacheType, "O", self));
+    Py_SETREF(self->statement_cache, (pysqlite_Cache *)PyObject_CallFunction(
+                                (PyObject *)&pysqlite_CacheType, "O", self));
     Py_DECREF(self);
     self->statement_cache->decref_factory = 0;
 }
@@ -319,7 +319,8 @@ PyObject* pysqlite_connection_cursor(pys
 
     if (cursor && self->row_factory != Py_None) {
         Py_INCREF(self->row_factory);
-        Py_SETREF(((pysqlite_Cursor *)cursor)->row_factory, self->row_factory);
+        Py_SETREF(((pysqlite_Cursor *)cursor)->row_factory,
+                  self->row_factory);
     }
 
     return cursor;
diff -r c4e8751ce637 Modules/_sqlite/cursor.c
--- a/Modules/_sqlite/cursor.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Modules/_sqlite/cursor.c	Thu Dec 24 10:58:52 2015 +0200
@@ -524,10 +524,10 @@ PyObject* _pysqlite_query_execute(pysqli
 
     if (self->statement) {
         (void)pysqlite_statement_reset(self->statement);
-        Py_DECREF(self->statement);
     }
 
-    self->statement = (pysqlite_Statement*)pysqlite_cache_get(self->connection->statement_cache, func_args);
+    Py_SETREF(self->statement,
+              (pysqlite_Statement*)pysqlite_cache_get(self->connection->statement_cache, func_args));
     Py_DECREF(func_args);
 
     if (!self->statement) {
diff -r c4e8751ce637 Modules/itertoolsmodule.c
--- a/Modules/itertoolsmodule.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Modules/itertoolsmodule.c	Thu Dec 24 10:58:52 2015 +0200
@@ -77,7 +77,7 @@ groupby_traverse(groupbyobject *gbo, vis
 static PyObject *
 groupby_next(groupbyobject *gbo)
 {
-    PyObject *newvalue, *newkey, *r, *grouper, *tmp;
+    PyObject *newvalue, *newkey, *r, *grouper;
 
     /* skip to next iteration group */
     for (;;) {
@@ -110,19 +110,12 @@ groupby_next(groupbyobject *gbo)
             }
         }
 
-        tmp = gbo->currkey;
-        gbo->currkey = newkey;
-        Py_XDECREF(tmp);
-
-        tmp = gbo->currvalue;
-        gbo->currvalue = newvalue;
-        Py_XDECREF(tmp);
+        Py_SETREF(gbo->currkey, newkey);
+        Py_SETREF(gbo->currvalue, newvalue);
     }
 
     Py_INCREF(gbo->currkey);
-    tmp = gbo->tgtkey;
-    gbo->tgtkey = gbo->currkey;
-    Py_XDECREF(tmp);
+    Py_SETREF(gbo->tgtkey, gbo->currkey);
 
     grouper = _grouper_create(gbo, gbo->tgtkey);
     if (grouper == NULL)
@@ -3456,7 +3449,7 @@ accumulate_traverse(accumulateobject *lz
 static PyObject *
 accumulate_next(accumulateobject *lz)
 {
-    PyObject *val, *oldtotal, *newtotal;
+    PyObject *val, *newtotal;
 
     val = (*Py_TYPE(lz->it)->tp_iternext)(lz->it);
     if (val == NULL)
@@ -3476,11 +3469,8 @@ accumulate_next(accumulateobject *lz)
     if (newtotal == NULL)
         return NULL;
 
-    oldtotal = lz->total;
-    lz->total = newtotal;
-    Py_DECREF(oldtotal);
-
     Py_INCREF(newtotal);
+    Py_SETREF(lz->total, newtotal);
     return newtotal;
 }
 
diff -r c4e8751ce637 Modules/pyexpat.c
--- a/Modules/pyexpat.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Modules/pyexpat.c	Thu Dec 24 10:58:52 2015 +0200
@@ -1226,12 +1226,8 @@ xmlparse_dealloc(xmlparseobject *self)
     self->itself = NULL;
 
     if (self->handlers != NULL) {
-        PyObject *temp;
-        for (i = 0; handler_info[i].name != NULL; i++) {
-            temp = self->handlers[i];
-            self->handlers[i] = NULL;
-            Py_XDECREF(temp);
-        }
+        for (i = 0; handler_info[i].name != NULL; i++)
+            Py_CLEAR(self->handlers[i]);
         PyMem_Free(self->handlers);
         self->handlers = NULL;
     }
@@ -1345,7 +1341,6 @@ sethandler(xmlparseobject *self, PyObjec
     int handlernum = handlername2int(name);
     if (handlernum >= 0) {
         xmlhandler c_handler = NULL;
-        PyObject *temp = self->handlers[handlernum];
 
         if (v == Py_None) {
             /* If this is the character data handler, and a character
@@ -1367,8 +1362,7 @@ sethandler(xmlparseobject *self, PyObjec
             Py_INCREF(v);
             c_handler = handler_info[handlernum].handler;
         }
-        self->handlers[handlernum] = v;
-        Py_XDECREF(temp);
+        Py_SETREF(self->handlers[handlernum], v);
         handler_info[handlernum].setter(self->itself, c_handler);
         return 1;
     }
@@ -1898,15 +1892,12 @@ static void
 clear_handlers(xmlparseobject *self, int initial)
 {
     int i = 0;
-    PyObject *temp;
 
     for (; handler_info[i].name != NULL; i++) {
         if (initial)
             self->handlers[i] = NULL;
         else {
-            temp = self->handlers[i];
-            self->handlers[i] = NULL;
-            Py_XDECREF(temp);
+            Py_CLEAR(self->handlers[i]);
             handler_info[i].setter(self->itself, NULL);
         }
     }
diff -r c4e8751ce637 Modules/zlibmodule.c
--- a/Modules/zlibmodule.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Modules/zlibmodule.c	Thu Dec 24 10:58:52 2015 +0200
@@ -961,14 +961,11 @@ zlib_Compress_copy_impl(compobject *self
         goto error;
     }
     Py_INCREF(self->unused_data);
+    Py_SETREF(retval->unused_data, self->unused_data);
     Py_INCREF(self->unconsumed_tail);
+    Py_SETREF(retval->unconsumed_tail, self->unconsumed_tail);
     Py_XINCREF(self->zdict);
-    Py_XDECREF(retval->unused_data);
-    Py_XDECREF(retval->unconsumed_tail);
-    Py_XDECREF(retval->zdict);
-    retval->unused_data = self->unused_data;
-    retval->unconsumed_tail = self->unconsumed_tail;
-    retval->zdict = self->zdict;
+    Py_SETREF(retval->zdict, self->zdict);
     retval->eof = self->eof;
 
     /* Mark it as being initialized */
@@ -1020,14 +1017,11 @@ zlib_Decompress_copy_impl(compobject *se
     }
 
     Py_INCREF(self->unused_data);
+    Py_SETREF(retval->unused_data, self->unused_data);
     Py_INCREF(self->unconsumed_tail);
+    Py_SETREF(retval->unconsumed_tail, self->unconsumed_tail);
     Py_XINCREF(self->zdict);
-    Py_XDECREF(retval->unused_data);
-    Py_XDECREF(retval->unconsumed_tail);
-    Py_XDECREF(retval->zdict);
-    retval->unused_data = self->unused_data;
-    retval->unconsumed_tail = self->unconsumed_tail;
-    retval->zdict = self->zdict;
+    Py_SETREF(retval->zdict, self->zdict);
     retval->eof = self->eof;
 
     /* Mark it as being initialized */
diff -r c4e8751ce637 Objects/listobject.c
--- a/Objects/listobject.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Objects/listobject.c	Thu Dec 24 10:58:52 2015 +0200
@@ -216,7 +216,6 @@ int
 PyList_SetItem(PyObject *op, Py_ssize_t i,
                PyObject *newitem)
 {
-    PyObject *olditem;
     PyObject **p;
     if (!PyList_Check(op)) {
         Py_XDECREF(newitem);
@@ -230,9 +229,7 @@ PyList_SetItem(PyObject *op, Py_ssize_t 
         return -1;
     }
     p = ((PyListObject *)op) -> ob_item + i;
-    olditem = *p;
-    *p = newitem;
-    Py_XDECREF(olditem);
+    Py_SETREF(*p, newitem);
     return 0;
 }
 
@@ -730,7 +727,6 @@ list_inplace_repeat(PyListObject *self, 
 static int
 list_ass_item(PyListObject *a, Py_ssize_t i, PyObject *v)
 {
-    PyObject *old_value;
     if (i < 0 || i >= Py_SIZE(a)) {
         PyErr_SetString(PyExc_IndexError,
                         "list assignment index out of range");
@@ -739,9 +735,7 @@ list_ass_item(PyListObject *a, Py_ssize_
     if (v == NULL)
         return list_ass_slice(a, i, i+1, v);
     Py_INCREF(v);
-    old_value = a->ob_item[i];
-    a->ob_item[i] = v;
-    Py_DECREF(old_value);
+    Py_SETREF(a->ob_item[i], v);
     return 0;
 }
 
diff -r c4e8751ce637 Objects/tupleobject.c
--- a/Objects/tupleobject.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Objects/tupleobject.c	Thu Dec 24 10:58:52 2015 +0200
@@ -149,7 +149,6 @@ PyTuple_GetItem(PyObject *op, Py_ssize_t
 int
 PyTuple_SetItem(PyObject *op, Py_ssize_t i, PyObject *newitem)
 {
-    PyObject *olditem;
     PyObject **p;
     if (!PyTuple_Check(op) || op->ob_refcnt != 1) {
         Py_XDECREF(newitem);
@@ -163,9 +162,7 @@ PyTuple_SetItem(PyObject *op, Py_ssize_t
         return -1;
     }
     p = ((PyTupleObject *)op) -> ob_item + i;
-    olditem = *p;
-    *p = newitem;
-    Py_XDECREF(olditem);
+    Py_SETREF(*p, newitem);
     return 0;
 }
 
diff -r c4e8751ce637 Objects/typeobject.c
--- a/Objects/typeobject.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Objects/typeobject.c	Thu Dec 24 10:58:52 2015 +0200
@@ -401,7 +401,6 @@ type_qualname(PyTypeObject *type, void *
 static int
 type_set_name(PyTypeObject *type, PyObject *value, void *context)
 {
-    PyHeapTypeObject* et;
     char *tp_name;
     PyObject *tmp;
 
@@ -430,17 +429,12 @@ type_set_name(PyTypeObject *type, PyObje
     if (tp_name == NULL)
         return -1;
 
-    et = (PyHeapTypeObject*)type;
-
     Py_INCREF(value);
 
     /* Wait until et is a sane state before Py_DECREF'ing the old et->ht_name
        value.  (Bug #16447.)  */
-    tmp = et->ht_name;
-    et->ht_name = value;
-
+    Py_SETREF(((PyHeapTypeObject*)type)->ht_name, value);
     type->tp_name = tp_name;
-    Py_DECREF(tmp);
 
     return 0;
 }
diff -r c4e8751ce637 Objects/unicodeobject.c
--- a/Objects/unicodeobject.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Objects/unicodeobject.c	Thu Dec 24 10:58:52 2015 +0200
@@ -14443,8 +14443,8 @@ unicode_format_arg_parse(struct unicode_
         if (key == NULL)
             return -1;
         if (ctx->args_owned) {
+            ctx->args_owned = 0;
             Py_DECREF(ctx->args);
-            ctx->args_owned = 0;
         }
         ctx->args = PyObject_GetItem(ctx->dict, key);
         Py_DECREF(key);
diff -r c4e8751ce637 Python/ast.c
--- a/Python/ast.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Python/ast.c	Thu Dec 24 10:58:52 2015 +0200
@@ -4692,11 +4692,8 @@ FstringParser_ConcatAndDel(FstringParser
         state->last_str = str;
     } else {
         /* Concatenate this with the previous string. */
-        PyObject *temp = PyUnicode_Concat(state->last_str, str);
-        Py_DECREF(state->last_str);
-        Py_DECREF(str);
-        state->last_str = temp;
-        if (!temp)
+        PyUnicode_AppendAndDel(&state->last_str, str);
+        if (!state->last_str)
             return -1;
     }
     FstringParser_check_invariants(state);
diff -r c4e8751ce637 Python/errors.c
--- a/Python/errors.c	Thu Dec 24 10:39:57 2015 +0200
+++ b/Python/errors.c	Thu Dec 24 10:58:52 2015 +0200
@@ -315,14 +315,11 @@ finally:
     tstate = PyThreadState_GET();
     if (++tstate->recursion_depth > Py_GetRecursionLimit()) {
         --tstate->recursion_depth;
-        /* throw away the old exception... */
-        Py_DECREF(*exc);
-        Py_DECREF(*val);
-        /* ... and use the recursion error instead */
-        *exc = PyExc_RecursionError;
-        *val = PyExc_RecursionErrorInst;
-        Py_INCREF(*exc);
-        Py_INCREF(*val);
+        /* throw away the old exception and use the recursion error instead */
+        Py_INCREF(PyExc_RecursionError);
+        Py_SETREF(*exc, PyExc_RecursionError);
+        Py_INCREF(PyExc_RecursionErrorInst);
+        Py_SETREF(*val, PyExc_RecursionErrorInst);
         /* just keeping the old traceback */
         return;
     }