[pypy-svn] pypy jit-short_from_state: Improve the comment documenting other invariant

[fijal]

Author: Maciej Fijalkowski <fijall at gmail.com>
Branch: jit-short_from_state
Changeset: r43394:87b741d57cc2
Date: 2011-04-16 11:20 +0200
http://bitbucket.org/pypy/pypy/changeset/87b741d57cc2/

Log:	Improve the comment documenting other invariant

diff --git a/pypy/rlib/jit.py b/pypy/rlib/jit.py
--- a/pypy/rlib/jit.py
+++ b/pypy/rlib/jit.py
@@ -13,6 +13,8 @@
         the same (same numbers or same pointers)
     (2) it's fine to remove the call completely if we can guess the result
     according to rule 1
+    (3) the function call can be moved around by optimizer,
+        but only so it'll be called earlier and not later.
 
     Most importantly it doesn't mean that pure function has no observable
     side effect, but those side effects can be ommited (ie caching).