changeset:   104580:61fcb12a9873
user:        Victor Stinner <victor.stinner@gmail.com>
date:        Thu Oct 20 12:18:10 2016 +0200
files:       Python/ceval.c
description:
Issue #21955: Please don't try to optimize int+int


diff -r 73ed94ebdbbc -r 61fcb12a9873 Python/ceval.c
--- a/Python/ceval.c	Thu Oct 20 01:36:52 2016 -0700
+++ b/Python/ceval.c	Thu Oct 20 12:18:10 2016 +0200
@@ -1424,6 +1424,12 @@
             PyObject *right = POP();
             PyObject *left = TOP();
             PyObject *sum;
+            /* NOTE(haypo): Please don't try to micro-optimize int+int on
+               CPython using bytecode, it is simply worthless.
+               See http://bugs.python.org/issue21955 and
+               http://bugs.python.org/issue10044 for the discussion. In short,
+               no patch shown any impact on a realistic benchmark, only a minor
+               speedup on microbenchmarks. */
             if (PyUnicode_CheckExact(left) &&
                      PyUnicode_CheckExact(right)) {
                 sum = unicode_concatenate(left, right, f, next_instr);