[pypy-commit] pypy emit-call-x86: Comments

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: emit-call-x86
Changeset: r64361:434a90ebaa43
Date: 2013-05-20 12:51 +0200
http://bitbucket.org/pypy/pypy/changeset/434a90ebaa43/

Log:	Comments

diff --git a/rpython/jit/backend/x86/callbuilder.py b/rpython/jit/backend/x86/callbuilder.py
--- a/rpython/jit/backend/x86/callbuilder.py
+++ b/rpython/jit/backend/x86/callbuilder.py
@@ -55,7 +55,7 @@
         self.resloc = resloc
         self.restype = restype
         self.ressize = ressize
-        self.current_esp = 0
+        self.current_esp = 0     # 0 or (usually) negative, counted in bytes
 
     def emit_no_collect(self):
         """Emit a call that cannot collect."""
@@ -107,7 +107,7 @@
 
     def restore_esp(self, target_esp=0):
         if self.current_esp != target_esp:
-            self.mc.SUB_ri(esp.value, self.current_esp - target_esp)
+            self.mc.ADD_ri(esp.value, target_esp - self.current_esp)
             self.current_esp = target_esp
 
     def load_result(self):