Constant propagation within __builtin_annot.

git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2126 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e

2 files changed, 30 insertions, 9 deletions

diff --git a/common/AST.v b/common/AST.v
index d2065d6b..44811b2b 100644
--- a/common/AST.v
+++ b/common/AST.v
@@ -443,7 +443,7 @@ Inductive external_function : Type :=
          Produces no observable event. *)
   | EF_memcpy (sz: Z) (al: Z)
      (** Block copy, of [sz] bytes, between addresses that are [al]-aligned. *)
-  | EF_annot (text: ident) (targs: list typ)
+  | EF_annot (text: ident) (targs: list annot_arg)
      (** A programmer-supplied annotation.  Takes zero, one or several arguments,
          produces an event carrying the text and the values of these arguments,
          and returns no value. *)
@@ -451,15 +451,27 @@ Inductive external_function : Type :=
      (** Another form of annotation that takes one argument, produces
          an event carrying the text and the value of this argument,
          and returns the value of the argument. *)
-  | EF_inline_asm (text: ident).
+  | EF_inline_asm (text: ident)
      (** Inline [asm] statements.  Semantically, treated like an
          annotation with no parameters ([EF_annot text nil]).  To be
          used with caution, as it can invalidate the semantic
          preservation theorem.  Generated only if [-finline-asm] is
          given. *)
 
+with annot_arg : Type :=
+  | AA_arg (ty: typ)
+  | AA_int (n: int)
+  | AA_float (n: float).
+
 (** The type signature of an external function. *)
 
+Fixpoint annot_args_typ (targs: list annot_arg) : list typ :=
+  match targs with
+  | nil => nil
+  | AA_arg ty :: targs' => ty :: annot_args_typ targs'
+  | _ :: targs' => annot_args_typ targs'
+  end.
+
 Definition ef_sig (ef: external_function): signature :=
   match ef with
   | EF_external name sg => sg
@@ -471,7 +483,7 @@ Definition ef_sig (ef: external_function): signature :=
   | EF_malloc => mksignature (Tint :: nil) (Some Tint)
   | EF_free => mksignature (Tint :: nil) None
   | EF_memcpy sz al => mksignature (Tint :: Tint :: nil) None
-  | EF_annot text targs => mksignature targs None
+  | EF_annot text targs => mksignature (annot_args_typ targs) None
   | EF_annot_val text targ => mksignature (targ :: nil) (Some targ)
   | EF_inline_asm text => mksignature nil None
   end.
diff --git a/common/Events.v b/common/Events.v
index 3f81e60e..e310bfed 100644
--- a/common/Events.v
+++ b/common/Events.v
@@ -1456,23 +1456,32 @@ Proof.
   intros EQ; inv EQ. split; auto. eapply eventval_match_determ_1; eauto.
 Qed.
 
-(** ** Semantics of annotation. *)
+(** ** Semantics of annotations. *)
+
+Fixpoint annot_eventvals (targs: list annot_arg) (vargs: list eventval) : list eventval :=
+  match targs, vargs with
+  | AA_arg ty :: targs', varg :: vargs' => varg :: annot_eventvals targs' vargs'
+  | AA_int n :: targs', _ => EVint n :: annot_eventvals targs' vargs
+  | AA_float n :: targs', _ => EVfloat n :: annot_eventvals targs' vargs
+  | _, _ => vargs
+  end.
 
-Inductive extcall_annot_sem (text: ident) (targs: list typ) (F V: Type) (ge: Genv.t F V):
+Inductive extcall_annot_sem (text: ident) (targs: list annot_arg) (F V: Type) (ge: Genv.t F V):
               list val -> mem -> trace -> val -> mem -> Prop :=
   | extcall_annot_sem_intro: forall vargs m args,
-      eventval_list_match ge args targs vargs ->
-      extcall_annot_sem text targs ge vargs m (Event_annot text args :: E0) Vundef m.
+      eventval_list_match ge args (annot_args_typ targs) vargs ->
+      extcall_annot_sem text targs ge vargs m
+           (Event_annot text (annot_eventvals targs args) :: E0) Vundef m.
 
 Lemma extcall_annot_ok:
   forall text targs,
-  extcall_properties (extcall_annot_sem text targs) (mksignature targs None).
+  extcall_properties (extcall_annot_sem text targs) (mksignature (annot_args_typ targs) None).
 Proof.
   intros; constructor; intros.
 (* well typed *)
   inv H. simpl. auto.
 (* arity *)
-  inv H. eapply eventval_list_match_length; eauto.
+  inv H. simpl. eapply eventval_list_match_length; eauto.
 (* symbols *)
   inv H1. econstructor; eauto. 
   eapply eventval_list_match_preserved; eauto.