From: scoder <stefan_ml@behnel.de>
Date: Mon, 11 May 2020 04:04:31 +0000 (+0200)
Subject: bpo-40575: Avoid unnecessary overhead in _PyDict_GetItemIdWithError() (GH-20018)
X-Git-Tag: v3.9.0b1~119
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=6067d4bc3ce5ff4cfa5b47ceecc84a3941bc031c;p=thirdparty%2FPython%2Fcpython.git

bpo-40575: Avoid unnecessary overhead in _PyDict_GetItemIdWithError() (GH-20018)

Avoid unnecessary overhead in _PyDict_GetItemIdWithError() by calling
_PyDict_GetItem_KnownHash() instead of the more generic PyDict_GetItemWithError(),
since we already know the hash of interned strings.
---

diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index fa35d16478f6..809a5ed77873 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -1492,7 +1492,9 @@ _PyDict_GetItemIdWithError(PyObject *dp, struct _Py_Identifier *key)
     kv = _PyUnicode_FromId(key); /* borrowed */
     if (kv == NULL)
         return NULL;
-    return PyDict_GetItemWithError(dp, kv);
+    Py_hash_t hash = ((PyASCIIObject *) kv)->hash;
+    assert (hash != -1);  /* interned strings have their hash value initialised */
+    return _PyDict_GetItem_KnownHash(dp, kv, hash);
 }
 
 PyObject *