Add freelist for ints with small number of digits

Author: eendebakpt

Include/internal/pycore_freelist_state.h

@@ -17,6 +17,7 @@ extern "C" {
 #  define Py_dictkeys_MAXFREELIST 80
 #  define Py_floats_MAXFREELIST 100
 #  define Py_ints_MAXFREELIST 100
+#  define PyLong_MAXSAVESIZE 8     // Keep freelists for all ints with less than this number of digits
 #  define Py_slices_MAXFREELIST 1
 #  define Py_contexts_MAXFREELIST 255
 #  define Py_async_gens_MAXFREELIST 80
@@ -39,8 +40,8 @@ struct _Py_freelist {
 
 struct _Py_freelists {
     struct _Py_freelist floats;
-    struct _Py_freelist ints;
     struct _Py_freelist tuples[PyTuple_MAXSAVESIZE];
+    struct _Py_freelist ints[PyLong_MAXSAVESIZE];
     struct _Py_freelist lists;
     struct _Py_freelist list_iters;
     struct _Py_freelist tuple_iters;

Objects/longobject.c

@@ -152,6 +152,22 @@ long_normalize(PyLongObject *v)
 # define MAX_LONG_DIGITS ((INT64_MAX-1) / PyLong_SHIFT)
 #endif
 
+static inline int
+maybe_freelist_push(PyObject *self)
+{
+    assert(PyLong_CheckExact(self));
+    assert(Py_IS_TYPE(self, &PyLong_Type));
+
+    PyLongObject *op = (PyLongObject *)self;
+    Py_ssize_t ndigits = _PyLong_DigitCount(op);
+
+    if (ndigits < PyLong_MAXSAVESIZE) {
+        return _Py_FREELIST_PUSH(ints[ndigits], self, Py_ints_MAXFREELIST);
+    }
+    return 0;
+}
+
+
 static PyLongObject *
 long_alloc(Py_ssize_t size)
 {
@@ -166,8 +182,8 @@ long_alloc(Py_ssize_t size)
      * assume that there is always at least one digit present. */
     Py_ssize_t ndigits = size ? size : 1;
 
-    if (ndigits == 1) {
-        result = (PyLongObject *)_Py_FREELIST_POP(PyLongObject, ints);
+    if (ndigits < PyLong_MAXSAVESIZE ) {
+        result = (PyLongObject *)_Py_FREELIST_POP(PyLongObject, ints[ndigits]);
     }
     if (result == NULL) {
         /* Number of bytes needed is: offsetof(PyLongObject, ob_digit) +
@@ -247,7 +263,7 @@ _PyLong_FromMedium(sdigit x)
     assert(!IS_SMALL_INT(x));
     assert(is_medium_int(x));
 
-    PyLongObject *v = (PyLongObject *)_Py_FREELIST_POP(PyLongObject, ints);
+    PyLongObject *v = (PyLongObject *)_Py_FREELIST_POP(PyLongObject, ints[1]);
     if (v == NULL) {
         v = PyObject_Malloc(sizeof(PyLongObject));
         if (v == NULL) {
@@ -3669,11 +3685,10 @@ _PyLong_ExactDealloc(PyObject *self)
         _Py_SetImmortal(self);
         return;
     }
-    if (_PyLong_IsCompact((PyLongObject *)self)) {
-        _Py_FREELIST_FREE(ints, self, PyObject_Free);
-        return;
+
+    if (!maybe_freelist_push(self)) {
+        PyObject_Free(self);
     }
-    PyObject_Free(self);
 }
 
 static void
@@ -3689,10 +3704,13 @@ long_dealloc(PyObject *self)
         _Py_SetImmortal(self);
         return;
     }
-    if (PyLong_CheckExact(self) && _PyLong_IsCompact((PyLongObject *)self)) {
-        _Py_FREELIST_FREE(ints, self, PyObject_Free);
+    if (PyLong_CheckExact(self))  {
+        if (!maybe_freelist_push(self)) {
+            PyObject_Free(self);
+        }
         return;
     }
+
     Py_TYPE(self)->tp_free(self);
 }
 

Objects/object.c

@@ -922,6 +922,9 @@ _PyObject_ClearFreeLists(struct _Py_freelists *freelists, int is_finalization)
     for (Py_ssize_t i = 0; i < PyTuple_MAXSAVESIZE; i++) {
         clear_freelist(&freelists->tuples[i], is_finalization, free_object);
     }
+    for (Py_ssize_t i = 0; i < PyLong_MAXSAVESIZE; i++) {
+        clear_freelist(&freelists->ints[i], is_finalization, free_object);
+    }
     clear_freelist(&freelists->lists, is_finalization, free_object);
     clear_freelist(&freelists->list_iters, is_finalization, free_object);
     clear_freelist(&freelists->tuple_iters, is_finalization, free_object);
@@ -938,7 +941,6 @@ _PyObject_ClearFreeLists(struct _Py_freelists *freelists, int is_finalization)
         clear_freelist(&freelists->object_stack_chunks, 1, PyMem_RawFree);
     }
     clear_freelist(&freelists->unicode_writers, is_finalization, PyMem_Free);
-    clear_freelist(&freelists->ints, is_finalization, free_object);
     clear_freelist(&freelists->pymethodobjects, is_finalization, free_object);
 }