Fixed issue #1564: The set implementation should special-case PyUnicode instead of PyString
I moved the unicode_eq to stringlib/eq.h to keep the function static and possible inline for setobject.c and dictobject.h. I also removed the unused _PyString_Eq method. If it's required in the future it can be added to eq.h
diff --git a/Objects/stringlib/eq.h b/Objects/stringlib/eq.h
new file mode 100644
index 0000000..4e989dc
--- /dev/null
+++ b/Objects/stringlib/eq.h
@@ -0,0 +1,21 @@
+/* Fast unicode equal function optimized for dictobject.c and setobject.c */
+
+/* Return 1 if two unicode objects are equal, 0 if not.
+ * unicode_eq() is called when the hash of two unicode objects is equal.
+ */
+Py_LOCAL_INLINE(int)
+unicode_eq(PyObject *aa, PyObject *bb)
+{
+ register PyUnicodeObject *a = (PyUnicodeObject *)aa;
+ register PyUnicodeObject *b = (PyUnicodeObject *)bb;
+
+ if (a->length != b->length)
+ return 0;
+ if (a->length == 0)
+ return 1;
+ if (a->str[0] != b->str[0])
+ return 0;
+ if (a->length == 1)
+ return 1;
+ return memcmp(a->str, b->str, a->length * sizeof(Py_UNICODE)) == 0;
+}