[pypy-commit] pypy fast-slowpath: Ah ha, found out that there was an assert preventing accesses below the

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: fast-slowpath
Changeset: r65737:332b124416bb
Date: 2013-07-28 13:37 +0200
http://bitbucket.org/pypy/pypy/changeset/332b124416bb/

Log:	Ah ha, found out that there was an assert preventing accesses below
	the value of esp, which was just silently killed. Reintroduce the
	assert and write comments.

diff --git a/rpython/jit/backend/x86/regloc.py b/rpython/jit/backend/x86/regloc.py
--- a/rpython/jit/backend/x86/regloc.py
+++ b/rpython/jit/backend/x86/regloc.py
@@ -89,7 +89,8 @@
     _location_code = 's'
 
     def __init__(self, value, type):
-        self.value = value
+        assert value >= 0     # accessing values < 0 is forbidden on x86-32.
+        self.value = value    # (on x86-64 we could allow values down to -128)
         self.type = type
 
     def _getregkey(self):