Re: [Python-Dev] cpython: Minor bit of factoring-out common code.

July 7, 2015

      On 07.07.15 05:08, raymond.hettinger wrote:
...
https://hg.python.org/cpython/rev/5088f2cd6293
changeset:   96866:5088f2cd6293
user:        Raymond Hettinger <python@rcn.com>
date:        Mon Jul 06 19:08:49 2015 -0700
summary:
   Minor bit of factoring-out common code.
...
+        if (rv < 0)
+            goto error;
          if (rv) {
-            if (set_add_entry(result, key, hash)) {
-                Py_DECREF(it);
-                Py_DECREF(result);
-                Py_DECREF(key);
-                return NULL;
-            }
+            if (set_add_entry(result, key, hash))
+                goto error;
          }
          Py_DECREF(key);
      }
In tight loop it may be worth to rewrite the code

     if (rv < 0)
         goto error;
     if (rv) {
         expensive_operation();
     }
     // if (rv == 0) do nothing

in the form:

     if (rv) {
         if (rv < 0)
             goto error;
         expensive_operation();
     }

This looks less clear, but needs only one test in the case of rv == 0.

Re: [Python-Dev] cpython: Minor bit of factoring-out common code.

Serhiy Storchaka