[pypy-commit] extradoc extradoc: Another thing I keep seeing.

[alex_gaynor]

Author: Alex Gaynor <alex.gaynor at gmail.com>
Branch: extradoc
Changeset: r3833:44e83b7f5d3d
Date: 2011-07-16 19:07 -0700
http://bitbucket.org/pypy/extradoc/changeset/44e83b7f5d3d/

Log:	Another thing I keep seeing.

diff --git a/planning/jit.txt b/planning/jit.txt
--- a/planning/jit.txt
+++ b/planning/jit.txt
@@ -80,6 +80,16 @@
   maybe we should move promote even higher, before the first use and we
   could possibly remove more stuff?
 
+  This shows up in another way as well, the Python code
+
+  if x is None:
+      i += x
+
+  We promote the guard_nonnull when we load x into guard_nonnull class,
+  however this happens after the optimizer sees `x is None`, so that ptr_eq
+  still remains, even though it's obviously not necessary since x and None
+  will have different known_classes.
+
 - f31 = f17 * f16
   f32 = f16 * f17