Refactoring of builtins and annotations in the back-end.

Before, the back-end languages had distinct instructions
- Iannot for annotations, taking structured expressions (annot_arg)
  as arguments, and producing no results'
- Ibuiltin for other builtins, using simple pseudoregs/locations/registers
  as arguments and results.

This branch enriches Ibuiltin instructions so that they take structured
expressions (builtin_arg and builtin_res) as arguments and results.
This way,
- Annotations fit the general pattern of builtin functions,
  so Iannot instructions are removed.
- EF_vload_global and EF_vstore_global become useless, as the
  same optimization can be achieved by EF_vload/vstore taking
  a structured argument of the "address of global" kind.
- Better code can be generated for builtin_memcpy between stack locations,
  or volatile accesses to stack locations.

Finally, this commit also introduces a new kind of external function,
EF_debug, which is like EF_annot but produces no observable events.
It will be used later to transport debug info through the back-end,
without preventing optimizations.

1 files changed, 0 insertions, 6 deletions

diff --git a/backend/CMparser.mly b/backend/CMparser.mly
index f62e05d4..b48a486e 100644
--- a/backend/CMparser.mly
+++ b/backend/CMparser.mly
@@ -42,12 +42,6 @@ let mkef sg toks =
       EF_vload c
   | [EFT_tok "volatile"; EFT_tok "store"; EFT_chunk c] ->
       EF_vstore c
-  | [EFT_tok "volatile"; EFT_tok "load"; EFT_chunk c; 
-     EFT_tok "global"; EFT_string s; EFT_int n] ->
-      EF_vload_global(c, intern_string s, coqint_of_camlint n)
-  | [EFT_tok "volatile"; EFT_tok "store"; EFT_chunk c; 
-     EFT_tok "global"; EFT_string s; EFT_int n] ->
-      EF_vstore_global(c, intern_string s, coqint_of_camlint n)
   | [EFT_tok "malloc"] ->
       EF_malloc
   | [EFT_tok "free"] ->