specialize for single element recycle

eendebakpt · eendebakpt · commit 272d4d1d630b · 2022-07-11T20:21:22.000+02:00
diff --git a/Objects/listobject.c b/Objects/listobject.c
@@ -692,7 +692,11 @@ list_ass_slice(PyListObject *a, Py_ssize_t ilow, Py_ssize_t ihigh, PyObject *v)
                 goto Error;
             }
         }
-        memcpy(recycle, &item[ilow], s);
+        if (norig==1)
+            recycle[0] = item[ilow];
+        else {
+            memcpy(recycle, &item[ilow], s);
+        }
     }
 
     if (d < 0) { /* Delete -d items */

Original file line number	Diff line number	Diff line change
`@@ -692,7 +692,11 @@ list_ass_slice(PyListObject a, Py_ssize_t ilow, Py_ssize_t ihigh, PyObject v)`
`692`	`692`	`goto Error;`
`693`	`693`	`}`
`694`	`694`	`}`
`695`		`- memcpy(recycle, &item[ilow], s);`
	`695`	`+ if (norig==1)`
	`696`	`+ recycle[0] = item[ilow];`
	`697`	`+ else {`
	`698`	`+ memcpy(recycle, &item[ilow], s);`
	`699`	`+ }`
`696`	`700`	`}`
`697`	`701`
`698`	`702`	`if (d < 0) { /* Delete -d items */`