diff -r 9f7d16266928 Python/compile.c
--- a/Python/compile.c	Tue Jan 17 03:46:13 2017 +0100
+++ b/Python/compile.c	Sat Jan 21 12:27:26 2017 +0900
@@ -158,12 +158,13 @@
     int c_interactive;           /* true if in interactive mode */
     int c_nestlevel;
 
     struct compiler_unit *u; /* compiler state for current block */
     PyObject *c_stack;           /* Python list holding compiler_unit ptrs */
     PyArena *c_arena;            /* pointer to memory allocation arena */
+    PyObject *c_tuplecache;      /* dict used for merge same tuples */
 };
 
 static int compiler_enter_scope(struct compiler *, identifier, int, void *, int);
 static void compiler_free(struct compiler *);
 static basicblock *compiler_new_block(struct compiler *);
 static int compiler_next_instr(struct compiler *, basicblock *);
@@ -317,12 +318,15 @@
     Py_INCREF(filename);
     c.c_filename = filename;
     c.c_arena = arena;
     c.c_future = PyFuture_FromASTObject(mod, filename);
     if (c.c_future == NULL)
         goto finally;
+    c.c_tuplecache = PyDict_New();
+    if (c.c_tuplecache == NULL)
+        goto finally;
     if (!flags) {
         local_flags.cf_flags = 0;
         flags = &local_flags;
     }
     merged = c.c_future->ff_features | flags->cf_flags;
     c.c_future->ff_features = merged;
@@ -380,12 +384,13 @@
 compiler_free(struct compiler *c)
 {
     if (c->c_st)
         PySymtable_Free(c->c_st);
     if (c->c_future)
         PyObject_Free(c->c_future);
+    Py_XDECREF(c->c_tuplecache);
     Py_XDECREF(c->c_filename);
     Py_DECREF(c->c_stack);
 }
 
 static PyObject *
 list2dict(PyObject *list)
@@ -5227,12 +5232,43 @@
         flags |= CO_NOFREE;
     }
 
     return flags;
 }
 
+static PyObject *
+merge_tuples(PyObject *cache, PyObject *tuple)
+{
+    if (tuple == NULL)
+        return NULL;
+
+    Py_ssize_t n = PyTuple_GET_SIZE(tuple);
+
+    // Check tuple is simple and safe.
+    // Note that integer and float are not safe, because 1 == 1.0 == True.
+    for (Py_ssize_t i=0; i < n; i++) {
+        PyObject *o = PyTuple_GET_ITEM(tuple, i);
+        if (o != Py_None && o != Py_True && o != Py_False &&
+                !PyUnicode_CheckExact(o) &&
+                !PyBytes_CheckExact(o)) {
+            return tuple;
+        }
+    }
+
+    PyObject *t = PyDict_SetDefault(cache, tuple, tuple);
+    if (t == NULL) { // Unhashable type is in consts?
+        PyErr_Clear();
+        return tuple;
+    }
+    if (t != tuple) {
+        Py_INCREF(t);
+        Py_DECREF(tuple);
+    }
+    return t;
+}
+
 static PyCodeObject *
 makecode(struct compiler *c, struct assembler *a)
 {
     PyObject *tmp;
     PyCodeObject *co = NULL;
     PyObject *consts = NULL;
@@ -5280,12 +5316,18 @@
     tmp = PyList_AsTuple(consts); /* PyCode_New requires a tuple */
     if (!tmp)
         goto error;
     Py_DECREF(consts);
     consts = tmp;
 
+    consts = merge_tuples(c->c_tuplecache, consts);
+    names = merge_tuples(c->c_tuplecache, names);
+    varnames = merge_tuples(c->c_tuplecache, varnames);
+    freevars = merge_tuples(c->c_tuplecache, freevars);
+    cellvars = merge_tuples(c->c_tuplecache, cellvars);
+
     argcount = Py_SAFE_DOWNCAST(c->u->u_argcount, Py_ssize_t, int);
     kwonlyargcount = Py_SAFE_DOWNCAST(c->u->u_kwonlyargcount, Py_ssize_t, int);
     co = PyCode_New(argcount, kwonlyargcount,
                     nlocals_int, stackdepth(c), flags,
                     bytecode, consts, names, varnames,
                     freevars, cellvars,