Merge of the "princeton" branch:

- Define type "block" as "positive" instead of "Z".
- Strengthen mem_unchanged_on so that the permissions are identical,
  instead of possibly increasing.
- Move mem_unchanged_on from Events to Memory.Mem.
- Define it in terms of mem_contents rather than in terms of Mem.load.
- ExportClight: try to name temporaries introduced by SimplExpr
- SimplExpr: avoid reusing temporaries between different functions,
  instead, thread a single generator through all functions.


git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2276 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e

1 files changed, 1 insertions, 1 deletions

diff --git a/backend/Mach.v b/backend/Mach.v
index 316e7887..f0fb56ae 100644
--- a/backend/Mach.v
+++ b/backend/Mach.v
@@ -273,7 +273,7 @@ Inductive state: Type :=
 
 Definition parent_sp (s: list stackframe) : val :=
   match s with
-  | nil => Vptr Mem.nullptr Int.zero
+  | nil => Vzero
   | Stackframe f sp ra c :: s' => sp
   end.