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authorGravatar xleroy <xleroy@fca1b0fc-160b-0410-b1d3-a4f43f01ea2e>2006-09-04 15:33:05 +0000
committerGravatar xleroy <xleroy@fca1b0fc-160b-0410-b1d3-a4f43f01ea2e>2006-09-04 15:33:05 +0000
commita7c6cf8d4d59e29ed73f9eb8bfc015b0384672a1 (patch)
tree3abfe8b71f399e1f73cd33fd618100f5a421351c /cfrontend/Cminorgenproof.v
parent73729d23ac13275c0d28d23bc1b1f6056104e5d9 (diff)
Revu la repartition des sources Coq en sous-repertoires
git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@73 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
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+(** Correctness proof for Cminor generation. *)
+
+Require Import Coqlib.
+Require Import Maps.
+Require Import Sets.
+Require Import AST.
+Require Import Integers.
+Require Import Floats.
+Require Import Values.
+Require Import Mem.
+Require Import Events.
+Require Import Globalenvs.
+Require Import Csharpminor.
+Require Import Op.
+Require Import Cminor.
+Require Cmconstr.
+Require Import Cminorgen.
+Require Import Cmconstrproof.
+
+Section TRANSLATION.
+
+Variable prog: Csharpminor.program.
+Variable tprog: program.
+Hypothesis TRANSL: transl_program prog = Some tprog.
+Let ge : Csharpminor.genv := Genv.globalenv (program_of_program prog).
+Let tge: genv := Genv.globalenv tprog.
+Let gce : compilenv := build_global_compilenv prog.
+
+Lemma symbols_preserved:
+ forall (s: ident), Genv.find_symbol tge s = Genv.find_symbol ge s.
+Proof.
+ intro. unfold ge, tge.
+ apply Genv.find_symbol_transf_partial with (transl_fundef gce).
+ exact TRANSL.
+Qed.
+
+Lemma function_ptr_translated:
+ forall (b: block) (f: Csharpminor.fundef),
+ Genv.find_funct_ptr ge b = Some f ->
+ exists tf,
+ Genv.find_funct_ptr tge b = Some tf /\ transl_fundef gce f = Some tf.
+Proof.
+ intros.
+ generalize
+ (Genv.find_funct_ptr_transf_partial (transl_fundef gce) TRANSL H).
+ case (transl_fundef gce f).
+ intros tf [A B]. exists tf. tauto.
+ intros [A B]. elim B. reflexivity.
+Qed.
+
+Lemma functions_translated:
+ forall (v: val) (f: Csharpminor.fundef),
+ Genv.find_funct ge v = Some f ->
+ exists tf,
+ Genv.find_funct tge v = Some tf /\ transl_fundef gce f = Some tf.
+Proof.
+ intros.
+ generalize
+ (Genv.find_funct_transf_partial (transl_fundef gce) TRANSL H).
+ case (transl_fundef gce f).
+ intros tf [A B]. exists tf. tauto.
+ intros [A B]. elim B. reflexivity.
+Qed.
+
+Lemma sig_preserved:
+ forall f tf,
+ transl_fundef gce f = Some tf ->
+ Cminor.funsig tf = Csharpminor.funsig f.
+Proof.
+ intros until tf; destruct f; simpl.
+ unfold transl_function. destruct (build_compilenv gce f).
+ case (zle z Int.max_signed); try congruence.
+ intro. case (transl_stmt c (Csharpminor.fn_body f)); simpl; try congruence.
+ intros. inversion H. reflexivity.
+ intro. inversion H; reflexivity.
+Qed.
+
+Definition global_compilenv_match (ce: compilenv) (gv: gvarenv) : Prop :=
+ forall id,
+ match ce!!id with
+ | Var_global_scalar chunk => gv!id = Some (Vscalar chunk)
+ | Var_global_array => True
+ | _ => False
+ end.
+
+Lemma global_compilenv_charact:
+ global_compilenv_match gce (global_var_env prog).
+Proof.
+ set (mkgve := fun gv (vars: list (ident * var_kind * list init_data)) =>
+ List.fold_left
+ (fun gve x => match x with (id, k, init) => PTree.set id k gve end)
+ vars gv).
+ assert (forall vars gv ce,
+ global_compilenv_match ce gv ->
+ global_compilenv_match (List.fold_left assign_global_variable vars ce)
+ (mkgve gv vars)).
+ induction vars; simpl; intros.
+ auto.
+ apply IHvars. intro id1. unfold assign_global_variable.
+ destruct a as [[id2 lv2] init2]. destruct lv2; simpl; rewrite PMap.gsspec; rewrite PTree.gsspec.
+ case (peq id1 id2); intro. auto. apply H.
+ case (peq id1 id2); intro. auto. apply H.
+
+ change (global_var_env prog) with (mkgve (PTree.empty var_kind) prog.(Csharpminor.prog_vars)).
+ unfold gce, build_global_compilenv. apply H.
+ intro. rewrite PMap.gi. auto.
+Qed.
+
+(** * Correspondence between Csharpminor's and Cminor's environments and memory states *)
+
+(** In Csharpminor, every variable is stored in a separate memory block.
+ In the corresponding Cminor code, some of these variables reside in
+ the local variable environment; others are sub-blocks of the stack data
+ block. We capture these changes in memory via a memory injection [f]:
+- [f b = None] means that the Csharpminor block [b] no longer exist
+ in the execution of the generated Cminor code. This corresponds to
+ a Csharpminor local variable translated to a Cminor local variable.
+- [f b = Some(b', ofs)] means that Csharpminor block [b] corresponds
+ to a sub-block of Cminor block [b] at offset [ofs].
+
+ A memory injection [f] defines a relation [val_inject f] between
+ values and a relation [mem_inject f] between memory states.
+ These relations, defined in file [Memory], will be used intensively
+ in our proof of simulation between Csharpminor and Cminor executions.
+
+ In the remainder of this section, we define relations between
+ Csharpminor and Cminor environments and call stacks. *)
+
+(** Matching for a Csharpminor variable [id].
+- If this variable is mapped to a Cminor local variable, the
+ corresponding Csharpminor memory block [b] must no longer exist in
+ Cminor ([f b = None]). Moreover, the content of block [b] must
+ match the value of [id] found in the Cminor local environment [te].
+- If this variable is mapped to a sub-block of the Cminor stack data
+ at offset [ofs], the address of this variable in Csharpminor [Vptr b
+ Int.zero] must match the address of the sub-block [Vptr sp (Int.repr
+ ofs)].
+*)
+
+Inductive match_var (f: meminj) (id: ident)
+ (e: Csharpminor.env) (m: mem) (te: env) (sp: block) :
+ var_info -> Prop :=
+ | match_var_local:
+ forall chunk b v v',
+ PTree.get id e = Some (b, Vscalar chunk) ->
+ Mem.load chunk m b 0 = Some v ->
+ f b = None ->
+ PTree.get id te = Some v' ->
+ val_inject f v v' ->
+ match_var f id e m te sp (Var_local chunk)
+ | match_var_stack_scalar:
+ forall chunk ofs b,
+ PTree.get id e = Some (b, Vscalar chunk) ->
+ val_inject f (Vptr b Int.zero) (Vptr sp (Int.repr ofs)) ->
+ match_var f id e m te sp (Var_stack_scalar chunk ofs)
+ | match_var_stack_array:
+ forall ofs sz b,
+ PTree.get id e = Some (b, Varray sz) ->
+ val_inject f (Vptr b Int.zero) (Vptr sp (Int.repr ofs)) ->
+ match_var f id e m te sp (Var_stack_array ofs)
+ | match_var_global_scalar:
+ forall chunk,
+ PTree.get id e = None ->
+ PTree.get id (global_var_env prog) = Some (Vscalar chunk) ->
+ match_var f id e m te sp (Var_global_scalar chunk)
+ | match_var_global_array:
+ PTree.get id e = None ->
+ match_var f id e m te sp (Var_global_array).
+
+(** Matching between a Csharpminor environment [e] and a Cminor
+ environment [te]. The [lo] and [hi] parameters delimit the range
+ of addresses for the blocks referenced from [te]. *)
+
+Record match_env (f: meminj) (cenv: compilenv)
+ (e: Csharpminor.env) (m: mem) (te: env) (sp: block)
+ (lo hi: Z) : Prop :=
+ mk_match_env {
+
+(** Each variable mentioned in the compilation environment must match
+ as defined above. *)
+ me_vars:
+ forall id, match_var f id e m te sp (PMap.get id cenv);
+
+(** The range [lo, hi] must not be empty. *)
+ me_low_high:
+ lo <= hi;
+
+(** Every block appearing in the Csharpminor environment [e] must be
+ in the range [lo, hi]. *)
+ me_bounded:
+ forall id b lv, PTree.get id e = Some(b, lv) -> lo <= b < hi;
+
+(** Distinct Csharpminor local variables must be mapped to distinct blocks. *)
+ me_inj:
+ forall id1 b1 lv1 id2 b2 lv2,
+ PTree.get id1 e = Some(b1, lv1) ->
+ PTree.get id2 e = Some(b2, lv2) ->
+ id1 <> id2 -> b1 <> b2;
+
+(** All blocks mapped to sub-blocks of the Cminor stack data must be in
+ the range [lo, hi]. *)
+ me_inv:
+ forall b delta,
+ f b = Some(sp, delta) -> lo <= b < hi;
+
+(** All Csharpminor blocks below [lo] (i.e. allocated before the blocks
+ referenced from [e]) must map to blocks that are below [sp]
+ (i.e. allocated before the stack data for the current Cminor function). *)
+ me_incr:
+ forall b tb delta,
+ f b = Some(tb, delta) -> b < lo -> tb < sp
+ }.
+
+(** Global environments match if the memory injection [f] leaves unchanged
+ the references to global symbols and functions. *)
+
+Record match_globalenvs (f: meminj) : Prop :=
+ mk_match_globalenvs {
+ mg_symbols:
+ forall id b,
+ Genv.find_symbol ge id = Some b ->
+ f b = Some (b, 0) /\ Genv.find_symbol tge id = Some b;
+ mg_functions:
+ forall b, b < 0 -> f b = Some(b, 0)
+ }.
+
+(** Call stacks represent abstractly the execution state of the current
+ Csharpminor and Cminor functions, as well as the states of the
+ calling functions. A call stack is a list of frames, each frame
+ collecting information on the current execution state of a Csharpminor
+ function and its Cminor translation. *)
+
+Record frame : Set :=
+ mkframe {
+ fr_cenv: compilenv;
+ fr_e: Csharpminor.env;
+ fr_te: env;
+ fr_sp: block;
+ fr_low: Z;
+ fr_high: Z
+ }.
+
+Definition callstack : Set := list frame.
+
+(** Matching of call stacks imply matching of environments for each of
+ the frames, plus matching of the global environments, plus disjointness
+ conditions over the memory blocks allocated for local variables
+ and Cminor stack data. *)
+
+Inductive match_callstack: meminj -> callstack -> Z -> Z -> mem -> Prop :=
+ | mcs_nil:
+ forall f bound tbound m,
+ match_globalenvs f ->
+ match_callstack f nil bound tbound m
+ | mcs_cons:
+ forall f cenv e te sp lo hi cs bound tbound m,
+ hi <= bound ->
+ sp < tbound ->
+ match_env f cenv e m te sp lo hi ->
+ match_callstack f cs lo sp m ->
+ match_callstack f (mkframe cenv e te sp lo hi :: cs) bound tbound m.
+
+(** The remainder of this section is devoted to showing preservation
+ of the [match_callstack] invariant under various assignments and memory
+ stores. First: preservation by memory stores to ``mapped'' blocks
+ (block that have a counterpart in the Cminor execution). *)
+
+Lemma match_env_store_mapped:
+ forall f cenv e m1 m2 te sp lo hi chunk b ofs v,
+ f b <> None ->
+ store chunk m1 b ofs v = Some m2 ->
+ match_env f cenv e m1 te sp lo hi ->
+ match_env f cenv e m2 te sp lo hi.
+Proof.
+ intros. inversion H1. constructor; auto.
+ (* vars *)
+ intros. generalize (me_vars0 id); intro.
+ inversion H2; econstructor; eauto.
+ rewrite <- H5. eapply load_store_other; eauto.
+ left. congruence.
+Qed.
+
+Lemma match_callstack_mapped:
+ forall f cs bound tbound m1,
+ match_callstack f cs bound tbound m1 ->
+ forall chunk b ofs v m2,
+ f b <> None ->
+ store chunk m1 b ofs v = Some m2 ->
+ match_callstack f cs bound tbound m2.
+Proof.
+ induction 1; intros; econstructor; eauto.
+ eapply match_env_store_mapped; eauto.
+Qed.
+
+(** Preservation by assignment to a Csharpminor variable that is
+ translated to a Cminor local variable. The value being assigned
+ must be normalized with respect to the memory chunk of the variable,
+ in the following sense. *)
+
+(*
+Definition val_normalized (chunk: memory_chunk) (v: val) : Prop :=
+ exists v0, v = Val.load_result chunk v0.
+
+Lemma load_result_idem:
+ forall chunk v,
+ Val.load_result chunk (Val.load_result chunk v) =
+ Val.load_result chunk v.
+Proof.
+ destruct chunk; destruct v; simpl; auto.
+ rewrite Int.cast8_signed_idem; auto.
+ rewrite Int.cast8_unsigned_idem; auto.
+ rewrite Int.cast16_signed_idem; auto.
+ rewrite Int.cast16_unsigned_idem; auto.
+ rewrite Float.singleoffloat_idem; auto.
+Qed.
+
+Lemma load_result_normalized:
+ forall chunk v,
+ val_normalized chunk v -> Val.load_result chunk v = v.
+Proof.
+ intros chunk v [v0 EQ]. rewrite EQ. apply load_result_idem.
+Qed.
+*)
+Lemma match_env_store_local:
+ forall f cenv e m1 m2 te sp lo hi id b chunk v tv,
+ e!id = Some(b, Vscalar chunk) ->
+ val_inject f (Val.load_result chunk v) tv ->
+ store chunk m1 b 0 v = Some m2 ->
+ match_env f cenv e m1 te sp lo hi ->
+ match_env f cenv e m2 (PTree.set id tv te) sp lo hi.
+Proof.
+ intros. inversion H2. constructor; auto.
+ intros. generalize (me_vars0 id0); intro.
+ inversion H3; subst.
+ (* var_local *)
+ case (peq id id0); intro.
+ (* the stored variable *)
+ subst id0.
+ change Csharpminor.var_kind with var_kind in H4.
+ rewrite H in H5. injection H5; clear H5; intros; subst b0 chunk0.
+ econstructor. eauto.
+ eapply load_store_same; eauto. auto.
+ rewrite PTree.gss. reflexivity.
+ auto.
+ (* a different variable *)
+ econstructor; eauto.
+ rewrite <- H6. eapply load_store_other; eauto.
+ rewrite PTree.gso; auto.
+ (* var_stack_scalar *)
+ econstructor; eauto.
+ (* var_stack_array *)
+ econstructor; eauto.
+ (* var_global_scalar *)
+ econstructor; eauto.
+ (* var_global_array *)
+ econstructor; eauto.
+Qed.
+
+Lemma match_env_store_above:
+ forall f cenv e m1 m2 te sp lo hi chunk b v,
+ store chunk m1 b 0 v = Some m2 ->
+ hi <= b ->
+ match_env f cenv e m1 te sp lo hi ->
+ match_env f cenv e m2 te sp lo hi.
+Proof.
+ intros. inversion H1; constructor; auto.
+ intros. generalize (me_vars0 id); intro.
+ inversion H2; econstructor; eauto.
+ rewrite <- H5. eapply load_store_other; eauto.
+ left. generalize (me_bounded0 _ _ _ H4). unfold block in *. omega.
+Qed.
+
+Lemma match_callstack_store_above:
+ forall f cs bound tbound m1,
+ match_callstack f cs bound tbound m1 ->
+ forall chunk b v m2,
+ store chunk m1 b 0 v = Some m2 ->
+ bound <= b ->
+ match_callstack f cs bound tbound m2.
+Proof.
+ induction 1; intros; econstructor; eauto.
+ eapply match_env_store_above with (b := b); eauto. omega.
+ eapply IHmatch_callstack; eauto.
+ inversion H1. omega.
+Qed.
+
+Lemma match_callstack_store_local:
+ forall f cenv e te sp lo hi cs bound tbound m1 m2 id b chunk v tv,
+ e!id = Some(b, Vscalar chunk) ->
+ val_inject f (Val.load_result chunk v) tv ->
+ store chunk m1 b 0 v = Some m2 ->
+ match_callstack f (mkframe cenv e te sp lo hi :: cs) bound tbound m1 ->
+ match_callstack f (mkframe cenv e (PTree.set id tv te) sp lo hi :: cs) bound tbound m2.
+Proof.
+ intros. inversion H2. constructor; auto.
+ eapply match_env_store_local; eauto.
+ eapply match_callstack_store_above; eauto.
+ inversion H16.
+ generalize (me_bounded0 _ _ _ H). omega.
+Qed.
+
+(** A variant of [match_callstack_store_local] where the Cminor environment
+ [te] already associates to [id] a value that matches the assigned value.
+ In this case, [match_callstack] is preserved even if no assignment
+ takes place on the Cminor side. *)
+
+Lemma match_env_extensional:
+ forall f cenv e m te1 sp lo hi,
+ match_env f cenv e m te1 sp lo hi ->
+ forall te2,
+ (forall id, te2!id = te1!id) ->
+ match_env f cenv e m te2 sp lo hi.
+Proof.
+ induction 1; intros; econstructor; eauto.
+ intros. generalize (me_vars0 id); intro.
+ inversion H0; econstructor; eauto.
+ rewrite H. auto.
+Qed.
+
+Lemma match_callstack_store_local_unchanged:
+ forall f cenv e te sp lo hi cs bound tbound m1 m2 id b chunk v tv,
+ e!id = Some(b, Vscalar chunk) ->
+ val_inject f (Val.load_result chunk v) tv ->
+ store chunk m1 b 0 v = Some m2 ->
+ te!id = Some tv ->
+ match_callstack f (mkframe cenv e te sp lo hi :: cs) bound tbound m1 ->
+ match_callstack f (mkframe cenv e te sp lo hi :: cs) bound tbound m2.
+Proof.
+ intros. inversion H3. constructor; auto.
+ apply match_env_extensional with (PTree.set id tv te).
+ eapply match_env_store_local; eauto.
+ intros. rewrite PTree.gsspec.
+ case (peq id0 id); intros. congruence. auto.
+ eapply match_callstack_store_above; eauto.
+ inversion H17.
+ generalize (me_bounded0 _ _ _ H). omega.
+Qed.
+
+(** Preservation of [match_callstack] by freeing all blocks allocated
+ for local variables at function entry (on the Csharpminor side). *)
+
+Lemma match_callstack_incr_bound:
+ forall f cs bound tbound m,
+ match_callstack f cs bound tbound m ->
+ forall bound' tbound',
+ bound <= bound' -> tbound <= tbound' ->
+ match_callstack f cs bound' tbound' m.
+Proof.
+ intros. inversion H; constructor; auto. omega. omega.
+Qed.
+
+Lemma load_freelist:
+ forall fbl chunk m b ofs,
+ (forall b', In b' fbl -> b' <> b) ->
+ load chunk (free_list m fbl) b ofs = load chunk m b ofs.
+Proof.
+ induction fbl; simpl; intros.
+ auto.
+ rewrite load_free. apply IHfbl.
+ intros. apply H. tauto.
+ apply sym_not_equal. apply H. tauto.
+Qed.
+
+Lemma match_env_freelist:
+ forall f cenv e m te sp lo hi fbl,
+ match_env f cenv e m te sp lo hi ->
+ (forall b, In b fbl -> hi <= b) ->
+ match_env f cenv e (free_list m fbl) te sp lo hi.
+Proof.
+ intros. inversion H. econstructor; eauto.
+ intros. generalize (me_vars0 id); intro.
+ inversion H1; econstructor; eauto.
+ rewrite <- H4. apply load_freelist.
+ intros. generalize (H0 _ H8); intro.
+ generalize (me_bounded0 _ _ _ H3). unfold block; omega.
+Qed.
+
+Lemma match_callstack_freelist_rec:
+ forall f cs bound tbound m,
+ match_callstack f cs bound tbound m ->
+ forall fbl,
+ (forall b, In b fbl -> bound <= b) ->
+ match_callstack f cs bound tbound (free_list m fbl).
+Proof.
+ induction 1; intros; constructor; auto.
+ eapply match_env_freelist; eauto.
+ intros. generalize (H3 _ H4). omega.
+ apply IHmatch_callstack. intros.
+ generalize (H3 _ H4). inversion H1. omega.
+Qed.
+
+Lemma match_callstack_freelist:
+ forall f cenv e te sp lo hi cs bound tbound m fbl,
+ (forall b, In b fbl -> lo <= b) ->
+ match_callstack f (mkframe cenv e te sp lo hi :: cs) bound tbound m ->
+ match_callstack f cs bound tbound (free_list m fbl).
+Proof.
+ intros. inversion H0. inversion H14.
+ apply match_callstack_incr_bound with lo sp.
+ apply match_callstack_freelist_rec. auto.
+ assumption.
+ omega. omega.
+Qed.
+
+(** Preservation of [match_callstack] when allocating a block for
+ a local variable on the Csharpminor side. *)
+
+Lemma load_from_alloc_is_undef:
+ forall m1 chunk m2 b,
+ alloc m1 0 (size_chunk chunk) = (m2, b) ->
+ load chunk m2 b 0 = Some Vundef.
+Proof.
+ intros.
+ assert (valid_block m2 b). eapply valid_new_block; eauto.
+ assert (low_bound m2 b <= 0).
+ generalize (low_bound_alloc _ _ b _ _ _ H). rewrite zeq_true. omega.
+ assert (0 + size_chunk chunk <= high_bound m2 b).
+ generalize (high_bound_alloc _ _ b _ _ _ H). rewrite zeq_true. omega.
+ elim (load_in_bounds _ _ _ _ H0 H1 H2). intros v LOAD.
+ assert (v = Vundef). eapply load_alloc_same; eauto.
+ congruence.
+Qed.
+
+Lemma match_env_alloc_same:
+ forall m1 lv m2 b info f1 cenv1 e1 te sp lo id data tv,
+ alloc m1 0 (sizeof lv) = (m2, b) ->
+ match info with
+ | Var_local chunk => data = None /\ lv = Vscalar chunk
+ | Var_stack_scalar chunk pos => data = Some(sp, pos) /\ lv = Vscalar chunk
+ | Var_stack_array pos => data = Some(sp, pos) /\ exists sz, lv = Varray sz
+ | Var_global_scalar chunk => False
+ | Var_global_array => False
+ end ->
+ match_env f1 cenv1 e1 m1 te sp lo m1.(nextblock) ->
+ te!id = Some tv ->
+ let f2 := extend_inject b data f1 in
+ let cenv2 := PMap.set id info cenv1 in
+ let e2 := PTree.set id (b, lv) e1 in
+ inject_incr f1 f2 ->
+ match_env f2 cenv2 e2 m2 te sp lo m2.(nextblock).
+Proof.
+ intros.
+ assert (b = m1.(nextblock)).
+ injection H; intros. auto.
+ assert (m2.(nextblock) = Zsucc m1.(nextblock)).
+ injection H; intros. rewrite <- H6; reflexivity.
+ inversion H1. constructor.
+ (* me_vars *)
+ intros id0. unfold cenv2. rewrite PMap.gsspec. case (peq id0 id); intros.
+ (* same var *)
+ subst id0. destruct info.
+ (* info = Var_local chunk *)
+ elim H0; intros.
+ apply match_var_local with b Vundef tv.
+ unfold e2; rewrite PTree.gss. congruence.
+ eapply load_from_alloc_is_undef; eauto.
+ rewrite H7 in H. unfold sizeof in H. eauto.
+ unfold f2, extend_inject, eq_block. rewrite zeq_true. auto.
+ auto.
+ constructor.
+ (* info = Var_stack_scalar chunk ofs *)
+ elim H0; intros.
+ apply match_var_stack_scalar with b.
+ unfold e2; rewrite PTree.gss. congruence.
+ eapply val_inject_ptr.
+ unfold f2, extend_inject, eq_block. rewrite zeq_true. eauto.
+ rewrite Int.add_commut. rewrite Int.add_zero. auto.
+ (* info = Var_stack_array z *)
+ elim H0; intros A [sz B].
+ apply match_var_stack_array with sz b.
+ unfold e2; rewrite PTree.gss. congruence.
+ eapply val_inject_ptr.
+ unfold f2, extend_inject, eq_block. rewrite zeq_true. eauto.
+ rewrite Int.add_commut. rewrite Int.add_zero. auto.
+ (* info = Var_global *)
+ contradiction.
+ contradiction.
+ (* other vars *)
+ generalize (me_vars0 id0); intros.
+ inversion H6; econstructor; eauto.
+ unfold e2; rewrite PTree.gso; auto.
+ unfold f2, extend_inject, eq_block; rewrite zeq_false; auto.
+ generalize (me_bounded0 _ _ _ H8). unfold block in *; omega.
+ unfold e2; rewrite PTree.gso; eauto.
+ unfold e2; rewrite PTree.gso; eauto.
+ unfold e2; rewrite PTree.gso; eauto.
+ unfold e2; rewrite PTree.gso; eauto.
+ (* lo <= hi *)
+ unfold block in *; omega.
+ (* me_bounded *)
+ intros until lv0. unfold e2; rewrite PTree.gsspec.
+ case (peq id0 id); intros.
+ subst id0. inversion H6. subst b0. unfold block in *; omega.
+ generalize (me_bounded0 _ _ _ H6). rewrite H5. omega.
+ (* me_inj *)
+ intros until lv2. unfold e2; repeat rewrite PTree.gsspec.
+ case (peq id1 id); case (peq id2 id); intros.
+ congruence.
+ inversion H6. subst b1. rewrite H4.
+ generalize (me_bounded0 _ _ _ H7). unfold block; omega.
+ inversion H7. subst b2. rewrite H4.
+ generalize (me_bounded0 _ _ _ H6). unfold block; omega.
+ eauto.
+ (* me_inv *)
+ intros until delta. unfold f2, extend_inject, eq_block.
+ case (zeq b0 b); intros.
+ subst b0. rewrite H4; rewrite H5. omega.
+ generalize (me_inv0 _ _ H6). rewrite H5. omega.
+ (* me_incr *)
+ intros until delta. unfold f2, extend_inject, eq_block.
+ case (zeq b0 b); intros.
+ subst b0. unfold block in *; omegaContradiction.
+ eauto.
+Qed.
+
+Lemma match_env_alloc_other:
+ forall f1 cenv e m1 m2 te sp lo hi chunk b data,
+ alloc m1 0 (sizeof chunk) = (m2, b) ->
+ match data with None => True | Some (b', delta') => sp < b' end ->
+ hi <= m1.(nextblock) ->
+ match_env f1 cenv e m1 te sp lo hi ->
+ let f2 := extend_inject b data f1 in
+ inject_incr f1 f2 ->
+ match_env f2 cenv e m2 te sp lo hi.
+Proof.
+ intros.
+ assert (b = m1.(nextblock)). injection H; auto.
+ rewrite <- H4 in H1.
+ inversion H2. constructor; auto.
+ (* me_vars *)
+ intros. generalize (me_vars0 id); intro.
+ inversion H5; econstructor; eauto.
+ unfold f2, extend_inject, eq_block. rewrite zeq_false. auto.
+ generalize (me_bounded0 _ _ _ H7). unfold block in *; omega.
+ (* me_bounded *)
+ intros until delta. unfold f2, extend_inject, eq_block.
+ case (zeq b0 b); intros. rewrite H5 in H0. omegaContradiction.
+ eauto.
+ (* me_incr *)
+ intros until delta. unfold f2, extend_inject, eq_block.
+ case (zeq b0 b); intros. subst b0. omegaContradiction.
+ eauto.
+Qed.
+
+Lemma match_callstack_alloc_other:
+ forall f1 cs bound tbound m1,
+ match_callstack f1 cs bound tbound m1 ->
+ forall lv m2 b data,
+ alloc m1 0 (sizeof lv) = (m2, b) ->
+ match data with None => True | Some (b', delta') => tbound <= b' end ->
+ bound <= m1.(nextblock) ->
+ let f2 := extend_inject b data f1 in
+ inject_incr f1 f2 ->
+ match_callstack f2 cs bound tbound m2.
+Proof.
+ induction 1; intros.
+ constructor.
+ inversion H. constructor.
+ intros. auto.
+ intros. elim (mg_symbols0 _ _ H4); intros.
+ split; auto. elim (H3 b0); intros; congruence.
+ intros. generalize (mg_functions0 _ H4). elim (H3 b0); congruence.
+ constructor. auto. auto.
+ unfold f2; eapply match_env_alloc_other; eauto.
+ destruct data; auto. destruct p. omega. omega.
+ unfold f2; eapply IHmatch_callstack; eauto.
+ destruct data; auto. destruct p. omega.
+ inversion H1; omega.
+Qed.
+
+Lemma match_callstack_alloc_left:
+ forall m1 lv m2 b info f1 cenv1 e1 te sp lo id data cs tv tbound,
+ alloc m1 0 (sizeof lv) = (m2, b) ->
+ match info with
+ | Var_local chunk => data = None /\ lv = Vscalar chunk
+ | Var_stack_scalar chunk pos => data = Some(sp, pos) /\ lv = Vscalar chunk
+ | Var_stack_array pos => data = Some(sp, pos) /\ exists sz, lv = Varray sz
+ | Var_global_scalar chunk => False
+ | Var_global_array => False
+ end ->
+ match_callstack f1 (mkframe cenv1 e1 te sp lo m1.(nextblock) :: cs) m1.(nextblock) tbound m1 ->
+ te!id = Some tv ->
+ let f2 := extend_inject b data f1 in
+ let cenv2 := PMap.set id info cenv1 in
+ let e2 := PTree.set id (b, lv) e1 in
+ inject_incr f1 f2 ->
+ match_callstack f2 (mkframe cenv2 e2 te sp lo m2.(nextblock) :: cs) m2.(nextblock) tbound m2.
+Proof.
+ intros. inversion H1. constructor. omega. auto.
+ unfold f2, cenv2, e2. eapply match_env_alloc_same; eauto.
+ unfold f2; eapply match_callstack_alloc_other; eauto.
+ destruct info.
+ elim H0; intros. rewrite H19. auto.
+ elim H0; intros. rewrite H19. omega.
+ elim H0; intros. rewrite H19. omega.
+ contradiction.
+ contradiction.
+ inversion H17; omega.
+Qed.
+
+Lemma match_callstack_alloc_right:
+ forall f cs bound tm1 m tm2 lo hi b,
+ alloc tm1 lo hi = (tm2, b) ->
+ match_callstack f cs bound tm1.(nextblock) m ->
+ match_callstack f cs bound tm2.(nextblock) m.
+Proof.
+ intros. eapply match_callstack_incr_bound; eauto. omega.
+ injection H; intros. rewrite <- H2; simpl. omega.
+Qed.
+
+Lemma match_env_alloc:
+ forall m1 l h m2 b tm1 tm2 tb f1 ce e te sp lo hi,
+ alloc m1 l h = (m2, b) ->
+ alloc tm1 l h = (tm2, tb) ->
+ match_env f1 ce e m1 te sp lo hi ->
+ hi <= m1.(nextblock) ->
+ sp < tm1.(nextblock) ->
+ let f2 := extend_inject b (Some(tb, 0)) f1 in
+ inject_incr f1 f2 ->
+ match_env f2 ce e m2 te sp lo hi.
+Proof.
+ intros.
+ assert (BEQ: b = m1.(nextblock)). injection H; auto.
+ assert (TBEQ: tb = tm1.(nextblock)). injection H0; auto.
+ inversion H1. constructor; auto.
+ (* me_vars *)
+ intros. generalize (me_vars0 id); intro. inversion H5.
+ (* var_local *)
+ econstructor; eauto.
+ generalize (me_bounded0 _ _ _ H7). intro.
+ unfold f2, extend_inject. case (eq_block b0 b); intro.
+ subst b0. rewrite BEQ in H12. omegaContradiction.
+ auto.
+ (* var_stack_scalar *)
+ econstructor; eauto.
+ (* var_stack_array *)
+ econstructor; eauto.
+ (* var_global_scalar *)
+ econstructor; eauto.
+ (* var_global_array *)
+ econstructor; eauto.
+ (* me_bounded *)
+ intros until delta. unfold f2, extend_inject. case (eq_block b0 b); intro.
+ intro. injection H5; clear H5; intros.
+ rewrite H6 in TBEQ. rewrite TBEQ in H3. omegaContradiction.
+ eauto.
+ (* me_inj *)
+ intros until delta. unfold f2, extend_inject. case (eq_block b0 b); intros.
+ injection H5; clear H5; intros; subst b0 tb0 delta.
+ rewrite BEQ in H6. omegaContradiction.
+ eauto.
+Qed.
+
+Lemma match_callstack_alloc_rec:
+ forall f1 cs bound tbound m1,
+ match_callstack f1 cs bound tbound m1 ->
+ forall l h m2 b tm1 tm2 tb,
+ alloc m1 l h = (m2, b) ->
+ alloc tm1 l h = (tm2, tb) ->
+ bound <= m1.(nextblock) ->
+ tbound <= tm1.(nextblock) ->
+ let f2 := extend_inject b (Some(tb, 0)) f1 in
+ inject_incr f1 f2 ->
+ match_callstack f2 cs bound tbound m2.
+Proof.
+ induction 1; intros.
+ constructor.
+ inversion H. constructor.
+ intros. elim (mg_symbols0 _ _ H5); intros.
+ split; auto. elim (H4 b0); intros; congruence.
+ intros. generalize (mg_functions0 _ H5). elim (H4 b0); congruence.
+ constructor. auto. auto.
+ unfold f2. eapply match_env_alloc; eauto. omega. omega.
+ unfold f2; eapply IHmatch_callstack; eauto.
+ inversion H1; omega.
+ omega.
+Qed.
+
+Lemma match_callstack_alloc:
+ forall f1 cs m1 tm1 l h m2 b tm2 tb,
+ match_callstack f1 cs m1.(nextblock) tm1.(nextblock) m1 ->
+ alloc m1 l h = (m2, b) ->
+ alloc tm1 l h = (tm2, tb) ->
+ let f2 := extend_inject b (Some(tb, 0)) f1 in
+ inject_incr f1 f2 ->
+ match_callstack f2 cs m2.(nextblock) tm2.(nextblock) m2.
+Proof.
+ intros. unfold f2 in *.
+ apply match_callstack_incr_bound with m1.(nextblock) tm1.(nextblock).
+ eapply match_callstack_alloc_rec; eauto. omega. omega.
+ injection H0; intros; subst m2; simpl; omega.
+ injection H1; intros; subst tm2; simpl; omega.
+Qed.
+
+(** [match_callstack] implies [match_globalenvs]. *)
+
+Lemma match_callstack_match_globalenvs:
+ forall f cs bound tbound m,
+ match_callstack f cs bound tbound m ->
+ match_globalenvs f.
+Proof.
+ induction 1; eauto.
+Qed.
+
+(** * Correctness of Cminor construction functions *)
+
+Hint Resolve eval_negint eval_negfloat eval_absfloat eval_intoffloat
+ eval_floatofint eval_floatofintu eval_notint eval_notbool
+ eval_cast8signed eval_cast8unsigned eval_cast16signed
+ eval_cast16unsigned eval_singleoffloat eval_add eval_add_ptr
+ eval_add_ptr_2 eval_sub eval_sub_ptr_int eval_sub_ptr_ptr
+ eval_mul eval_divs eval_mods eval_divu eval_modu
+ eval_and eval_or eval_xor eval_shl eval_shr eval_shru
+ eval_addf eval_subf eval_mulf eval_divf
+ eval_cmp eval_cmp_null_r eval_cmp_null_l eval_cmp_ptr
+ eval_cmpu eval_cmpf: evalexpr.
+
+Remark val_inject_val_of_bool:
+ forall f b, val_inject f (Val.of_bool b) (Val.of_bool b).
+Proof.
+ intros; destruct b; unfold Val.of_bool, Vtrue, Vfalse; constructor.
+Qed.
+
+Ltac TrivialOp :=
+ match goal with
+ | [ |- exists x, _ /\ val_inject _ (Vint ?x) _ ] =>
+ exists (Vint x); split;
+ [eauto with evalexpr | constructor]
+ | [ |- exists x, _ /\ val_inject _ (Vfloat ?x) _ ] =>
+ exists (Vfloat x); split;
+ [eauto with evalexpr | constructor]
+ | [ |- exists x, _ /\ val_inject _ (Val.of_bool ?x) _ ] =>
+ exists (Val.of_bool x); split;
+ [eauto with evalexpr | apply val_inject_val_of_bool]
+ | _ => idtac
+ end.
+
+Remark eval_compare_null_inv:
+ forall c i v,
+ Csharpminor.eval_compare_null c i = Some v ->
+ i = Int.zero /\ (c = Ceq /\ v = Vfalse \/ c = Cne /\ v = Vtrue).
+Proof.
+ intros until v. unfold Csharpminor.eval_compare_null.
+ predSpec Int.eq Int.eq_spec i Int.zero.
+ case c; intro EQ; simplify_eq EQ; intro; subst v; tauto.
+ congruence.
+Qed.
+
+(** Correctness of [make_op]. The generated Cminor code evaluates
+ to a value that matches the result value of the Csharpminor operation,
+ provided arguments match pairwise ([val_list_inject f] hypothesis). *)
+
+Lemma make_op_correct:
+ forall al a op vl m2 v sp le te1 tm1 t te2 tm2 tvl f,
+ make_op op al = Some a ->
+ Csharpminor.eval_operation op vl m2 = Some v ->
+ eval_exprlist tge (Vptr sp Int.zero) le te1 tm1 al t te2 tm2 tvl ->
+ val_list_inject f vl tvl ->
+ mem_inject f m2 tm2 ->
+ exists tv,
+ eval_expr tge (Vptr sp Int.zero) le te1 tm1 a t te2 tm2 tv
+ /\ val_inject f v tv.
+Proof.
+ intros.
+ destruct al as [ | a1 al];
+ [idtac | destruct al as [ | a2 al];
+ [idtac | destruct al as [ | a3 al]]];
+ simpl in H; try discriminate.
+ (* Constant operators *)
+ inversion H1. subst sp0 le0 e m te2 tm1 tvl.
+ inversion H2. subst vl.
+ destruct op; simplify_eq H; intro; subst a;
+ simpl in H0; injection H0; intro; subst v.
+ (* intconst *)
+ TrivialOp. econstructor. constructor. reflexivity.
+ (* floatconst *)
+ TrivialOp. econstructor. constructor. reflexivity.
+ (* Unary operators *)
+ inversion H1; clear H1; subst.
+ inversion H11; clear H11; subst.
+ rewrite E0_right.
+ inversion H2; clear H2; subst. inversion H8; clear H8; subst.
+ destruct op; simplify_eq H; intro; subst a;
+ simpl in H0; destruct v1; simplify_eq H0; intro; subst v;
+ inversion H7; subst v0;
+ TrivialOp.
+ change (Vint (Int.cast8unsigned i)) with (Val.cast8unsigned (Vint i)). eauto with evalexpr.
+ change (Vint (Int.cast8signed i)) with (Val.cast8signed (Vint i)). eauto with evalexpr.
+ change (Vint (Int.cast16unsigned i)) with (Val.cast16unsigned (Vint i)). eauto with evalexpr.
+ change (Vint (Int.cast16signed i)) with (Val.cast16signed (Vint i)). eauto with evalexpr.
+ change (Vfloat (Float.singleoffloat f0)) with (Val.singleoffloat (Vfloat f0)). eauto with evalexpr.
+ (* Binary operations *)
+ inversion H1; clear H1; subst. inversion H11; clear H11; subst.
+ inversion H12; clear H12; subst. rewrite E0_right.
+ inversion H2; clear H2; subst. inversion H9; clear H9; subst.
+ inversion H10; clear H10; subst.
+ destruct op; simplify_eq H; intro; subst a;
+ simpl in H0; destruct v2; destruct v3; simplify_eq H0; intro; try subst v;
+ inversion H7; inversion H8; subst v0; subst v1;
+ TrivialOp.
+ (* add int ptr *)
+ exists (Vptr b2 (Int.add ofs2 i)); split.
+ eauto with evalexpr. apply val_inject_ptr with x. auto.
+ subst ofs2. repeat rewrite Int.add_assoc. decEq. apply Int.add_commut.
+ (* add ptr int *)
+ exists (Vptr b2 (Int.add ofs2 i0)); split.
+ eauto with evalexpr. apply val_inject_ptr with x. auto.
+ subst ofs2. repeat rewrite Int.add_assoc. decEq. apply Int.add_commut.
+ (* sub ptr int *)
+ exists (Vptr b2 (Int.sub ofs2 i0)); split.
+ eauto with evalexpr. apply val_inject_ptr with x. auto.
+ subst ofs2. apply Int.sub_add_l.
+ (* sub ptr ptr *)
+ destruct (eq_block b b0); simplify_eq H0; intro; subst v; subst b0.
+ assert (b4 = b2). congruence. subst b4.
+ exists (Vint (Int.sub ofs3 ofs2)); split.
+ eauto with evalexpr.
+ subst ofs2 ofs3. replace x0 with x. rewrite Int.sub_shifted. constructor.
+ congruence.
+ (* divs *)
+ generalize (Int.eq_spec i0 Int.zero); destruct (Int.eq i0 Int.zero); intro;
+ simplify_eq H0; intro; subst v. TrivialOp.
+ (* divu *)
+ generalize (Int.eq_spec i0 Int.zero); destruct (Int.eq i0 Int.zero); intro;
+ simplify_eq H0; intro; subst v. TrivialOp.
+ (* mods *)
+ generalize (Int.eq_spec i0 Int.zero); destruct (Int.eq i0 Int.zero); intro;
+ simplify_eq H0; intro; subst v. TrivialOp.
+ (* modu *)
+ generalize (Int.eq_spec i0 Int.zero); destruct (Int.eq i0 Int.zero); intro;
+ simplify_eq H0; intro; subst v. TrivialOp.
+ (* shl *)
+ caseEq (Int.ltu i0 (Int.repr 32)); intro EQ; rewrite EQ in H0;
+ simplify_eq H0; intro; subst v. TrivialOp.
+ (* shr *)
+ caseEq (Int.ltu i0 (Int.repr 32)); intro EQ; rewrite EQ in H0;
+ simplify_eq H0; intro; subst v. TrivialOp.
+ (* shru *)
+ caseEq (Int.ltu i0 (Int.repr 32)); intro EQ; rewrite EQ in H0;
+ simplify_eq H0; intro; subst v. TrivialOp.
+ (* cmp int ptr *)
+ elim (eval_compare_null_inv _ _ _ H0); intros; subst i1 i.
+ exists v; split. eauto with evalexpr.
+ elim H12; intros [A B]; subst v; unfold Vtrue, Vfalse; constructor.
+ (* cmp ptr int *)
+ elim (eval_compare_null_inv _ _ _ H0); intros; subst i1 i0.
+ exists v; split. eauto with evalexpr.
+ elim H12; intros [A B]; subst v; unfold Vtrue, Vfalse; constructor.
+ (* cmp ptr ptr *)
+ caseEq (valid_pointer m2 b (Int.signed i) && valid_pointer m2 b0 (Int.signed i0));
+ intro EQ; rewrite EQ in H0; try discriminate.
+ destruct (eq_block b b0); simplify_eq H0; intro; subst v b0.
+ assert (b4 = b2); [congruence|subst b4].
+ assert (x0 = x); [congruence|subst x0].
+ elim (andb_prop _ _ EQ); intros.
+ exists (Val.of_bool (Int.cmp c ofs3 ofs2)); split.
+ eauto with evalexpr.
+ subst ofs2 ofs3. rewrite Int.translate_cmp.
+ apply val_inject_val_of_bool.
+ eapply valid_pointer_inject_no_overflow; eauto.
+ eapply valid_pointer_inject_no_overflow; eauto.
+Qed.
+
+(** Correctness of [make_cast]. Note that the resulting Cminor value is
+ normalized according to the given memory chunk. *)
+
+Lemma make_cast_correct:
+ forall f sp le te1 tm1 a t te2 tm2 v chunk tv,
+ eval_expr tge (Vptr sp Int.zero) le te1 tm1 a t te2 tm2 tv ->
+ val_inject f v tv ->
+ exists tv',
+ eval_expr tge (Vptr sp Int.zero) le
+ te1 tm1 (make_cast chunk a)
+ t te2 tm2 tv'
+ /\ val_inject f (Val.load_result chunk v) tv'.
+Proof.
+ intros. destruct chunk.
+
+ exists (Val.cast8signed tv).
+ split. apply eval_cast8signed; auto.
+ inversion H0; simpl; constructor.
+
+ exists (Val.cast8unsigned tv).
+ split. apply eval_cast8unsigned; auto.
+ inversion H0; simpl; constructor.
+
+ exists (Val.cast16signed tv).
+ split. apply eval_cast16signed; auto.
+ inversion H0; simpl; constructor.
+
+ exists (Val.cast16unsigned tv).
+ split. apply eval_cast16unsigned; auto.
+ inversion H0; simpl; constructor.
+
+ exists tv.
+ split. simpl; auto.
+ inversion H0; simpl; econstructor; eauto.
+
+ exists (Val.singleoffloat tv).
+ split. apply eval_singleoffloat; auto.
+ inversion H0; simpl; constructor.
+
+ exists tv.
+ split. simpl; auto.
+ inversion H0; simpl; constructor.
+Qed.
+
+Lemma make_stackaddr_correct:
+ forall sp le te tm ofs,
+ eval_expr tge (Vptr sp Int.zero) le
+ te tm (make_stackaddr ofs)
+ E0 te tm (Vptr sp (Int.repr ofs)).
+Proof.
+ intros; unfold make_stackaddr.
+ eapply eval_Eop. econstructor. simpl. decEq. decEq.
+ rewrite Int.add_commut. apply Int.add_zero.
+Qed.
+
+Lemma make_globaladdr_correct:
+ forall sp le te tm id b,
+ Genv.find_symbol tge id = Some b ->
+ eval_expr tge (Vptr sp Int.zero) le
+ te tm (make_globaladdr id)
+ E0 te tm (Vptr b Int.zero).
+Proof.
+ intros; unfold make_globaladdr.
+ eapply eval_Eop. econstructor. simpl. rewrite H. auto.
+Qed.
+
+(** Correctness of [make_load] and [make_store]. *)
+
+Lemma make_load_correct:
+ forall sp le te1 tm1 a t te2 tm2 va chunk v,
+ eval_expr tge (Vptr sp Int.zero) le te1 tm1 a t te2 tm2 va ->
+ Mem.loadv chunk tm2 va = Some v ->
+ eval_expr tge (Vptr sp Int.zero) le
+ te1 tm1 (make_load chunk a)
+ t te2 tm2 v.
+Proof.
+ intros; unfold make_load.
+ eapply eval_load; eauto.
+Qed.
+
+Lemma store_arg_content_inject:
+ forall f sp le te1 tm1 a t te2 tm2 v va chunk,
+ eval_expr tge (Vptr sp Int.zero) le te1 tm1 a t te2 tm2 va ->
+ val_inject f v va ->
+ exists vb,
+ eval_expr tge (Vptr sp Int.zero) le te1 tm1 (store_arg chunk a) t te2 tm2 vb
+ /\ val_content_inject f (mem_chunk chunk) v vb.
+Proof.
+ intros.
+ assert (exists vb,
+ eval_expr tge (Vptr sp Int.zero) le te1 tm1 a t te2 tm2 vb
+ /\ val_content_inject f (mem_chunk chunk) v vb).
+ exists va; split. assumption. constructor. assumption.
+ inversion H; clear H; subst; simpl; trivial.
+ inversion H2; clear H2; subst; trivial.
+ inversion H4; clear H4; subst; trivial.
+ rewrite E0_right. rewrite E0_right in H1.
+ destruct op; trivial; destruct chunk; trivial;
+ exists v0; (split; [auto|
+ simpl in H3; inversion H3; clear H3; subst va;
+ destruct v0; simpl in H0; inversion H0; subst; try (constructor; constructor)]).
+ apply val_content_inject_8. apply Int.cast8_unsigned_signed.
+ apply val_content_inject_8. apply Int.cast8_unsigned_idem.
+ apply val_content_inject_16. apply Int.cast16_unsigned_signed.
+ apply val_content_inject_16. apply Int.cast16_unsigned_idem.
+ apply val_content_inject_32. apply Float.singleoffloat_idem.
+Qed.
+
+Lemma make_store_correct:
+ forall f sp te1 tm1 addr te2 tm2 tvaddr rhs te3 tm3 tvrhs
+ chunk vrhs m3 vaddr m4 t1 t2,
+ eval_expr tge (Vptr sp Int.zero) nil
+ te1 tm1 addr t1 te2 tm2 tvaddr ->
+ eval_expr tge (Vptr sp Int.zero) nil
+ te2 tm2 rhs t2 te3 tm3 tvrhs ->
+ Mem.storev chunk m3 vaddr vrhs = Some m4 ->
+ mem_inject f m3 tm3 ->
+ val_inject f vaddr tvaddr ->
+ val_inject f vrhs tvrhs ->
+ exists tm4,
+ exec_stmt tge (Vptr sp Int.zero)
+ te1 tm1 (make_store chunk addr rhs)
+ (t1**t2) te3 tm4 Out_normal
+ /\ mem_inject f m4 tm4
+ /\ nextblock tm4 = nextblock tm3.
+Proof.
+ intros. unfold make_store.
+ exploit store_arg_content_inject. eexact H0. eauto.
+ intros [tv [EVAL VCINJ]].
+ exploit storev_mapped_inject_1; eauto.
+ intros [tm4 [STORE MEMINJ]].
+ exploit eval_store. eexact H. eexact EVAL. eauto.
+ intro EVALSTORE.
+ exists tm4.
+ split. apply exec_Sexpr with tv. auto.
+ split. auto.
+ unfold storev in STORE; destruct tvaddr; try discriminate.
+ exploit store_inv; eauto. simpl. tauto.
+Qed.
+
+(** Correctness of the variable accessors [var_get], [var_set]
+ and [var_addr]. *)
+
+Lemma var_get_correct:
+ forall cenv id a f e te sp lo hi m cs tm b chunk v le,
+ var_get cenv id = Some a ->
+ match_callstack f (mkframe cenv e te sp lo hi :: cs) m.(nextblock) tm.(nextblock) m ->
+ mem_inject f m tm ->
+ eval_var_ref prog e id b chunk ->
+ load chunk m b 0 = Some v ->
+ exists tv,
+ eval_expr tge (Vptr sp Int.zero) le te tm a E0 te tm tv /\
+ val_inject f v tv.
+Proof.
+ unfold var_get; intros.
+ assert (match_var f id e m te sp cenv!!id).
+ inversion H0. inversion H17. auto.
+ inversion H4; subst; rewrite <- H5 in H; inversion H; subst.
+ (* var_local *)
+ inversion H2; [subst|congruence].
+ exists v'; split.
+ apply eval_Evar. auto.
+ replace v with v0. auto. congruence.
+ (* var_stack_scalar *)
+ inversion H2; [subst|congruence].
+ assert (b0 = b). congruence. subst b0.
+ assert (chunk0 = chunk). congruence. subst chunk0.
+ exploit loadv_inject; eauto.
+ unfold loadv. eexact H3.
+ intros [tv [LOAD INJ]].
+ exists tv; split.
+ eapply make_load_correct; eauto. eapply make_stackaddr_correct; eauto.
+ auto.
+ (* var_global_scalar *)
+ inversion H2; [congruence|subst].
+ assert (match_globalenvs f). eapply match_callstack_match_globalenvs; eauto.
+ inversion H11. destruct (mg_symbols0 _ _ H9) as [A B].
+ assert (chunk0 = chunk). congruence. subst chunk0.
+ assert (loadv chunk m (Vptr b Int.zero) = Some v). assumption.
+ assert (val_inject f (Vptr b Int.zero) (Vptr b Int.zero)).
+ econstructor; eauto.
+ generalize (loadv_inject _ _ _ _ _ _ _ H1 H12 H13).
+ intros [tv [LOAD INJ]].
+ exists tv; split.
+ eapply make_load_correct; eauto. eapply make_globaladdr_correct; eauto.
+ auto.
+Qed.
+
+Lemma var_addr_correct:
+ forall cenv id a f e te sp lo hi m cs tm b le,
+ match_callstack f (mkframe cenv e te sp lo hi :: cs) m.(nextblock) tm.(nextblock) m ->
+ var_addr cenv id = Some a ->
+ eval_var_addr prog e id b ->
+ exists tv,
+ eval_expr tge (Vptr sp Int.zero) le te tm a E0 te tm tv /\
+ val_inject f (Vptr b Int.zero) tv.
+Proof.
+ unfold var_addr; intros.
+ assert (match_var f id e m te sp cenv!!id).
+ inversion H. inversion H15. auto.
+ inversion H2; subst; rewrite <- H3 in H0; inversion H0; subst; clear H0.
+ (* var_stack_scalar *)
+ inversion H1; [subst|congruence].
+ exists (Vptr sp (Int.repr ofs)); split.
+ eapply make_stackaddr_correct.
+ replace b with b0. auto. congruence.
+ (* var_stack_array *)
+ inversion H1; [subst|congruence].
+ exists (Vptr sp (Int.repr ofs)); split.
+ eapply make_stackaddr_correct.
+ replace b with b0. auto. congruence.
+ (* var_global_scalar *)
+ inversion H1; [congruence|subst].
+ assert (match_globalenvs f). eapply match_callstack_match_globalenvs; eauto.
+ inversion H7. destruct (mg_symbols0 _ _ H6) as [A B].
+ exists (Vptr b Int.zero); split.
+ eapply make_globaladdr_correct. eauto.
+ econstructor; eauto.
+ (* var_global_array *)
+ inversion H1; [congruence|subst].
+ assert (match_globalenvs f). eapply match_callstack_match_globalenvs; eauto.
+ inversion H6. destruct (mg_symbols0 _ _ H5) as [A B].
+ exists (Vptr b Int.zero); split.
+ eapply make_globaladdr_correct. eauto.
+ econstructor; eauto.
+Qed.
+
+Lemma var_set_correct:
+ forall cenv id rhs a f e te2 sp lo hi m2 cs tm2 te1 tm1 tv b chunk v m3 t,
+ var_set cenv id rhs = Some a ->
+ match_callstack f (mkframe cenv e te2 sp lo hi :: cs) m2.(nextblock) tm2.(nextblock) m2 ->
+ eval_expr tge (Vptr sp Int.zero) nil te1 tm1 rhs t te2 tm2 tv ->
+ val_inject f v tv ->
+ mem_inject f m2 tm2 ->
+ eval_var_ref prog e id b chunk ->
+ store chunk m2 b 0 v = Some m3 ->
+ exists te3, exists tm3,
+ exec_stmt tge (Vptr sp Int.zero) te1 tm1 a t te3 tm3 Out_normal /\
+ mem_inject f m3 tm3 /\
+ match_callstack f (mkframe cenv e te3 sp lo hi :: cs) m3.(nextblock) tm3.(nextblock) m3.
+Proof.
+ unfold var_set; intros.
+ assert (NEXTBLOCK: nextblock m3 = nextblock m2).
+ exploit store_inv; eauto. simpl; tauto.
+ inversion H0. subst f0 cenv0 e0 te sp0 lo0 hi0 cs0 bound tbound m.
+ assert (match_var f id e m2 te2 sp cenv!!id). inversion H19; auto.
+ inversion H6; subst; rewrite <- H7 in H; inversion H; subst; clear H.
+ (* var_local *)
+ inversion H4; [subst|congruence].
+ assert (b0 = b). congruence. subst b0.
+ assert (chunk0 = chunk). congruence. subst chunk0.
+ exploit make_cast_correct; eauto.
+ intros [tv' [EVAL INJ]].
+ exists (PTree.set id tv' te2); exists tm2.
+ split. eapply exec_Sexpr. eapply eval_Eassign. eauto.
+ split. eapply store_unmapped_inject; eauto.
+ rewrite NEXTBLOCK. eapply match_callstack_store_local; eauto.
+ (* var_stack_scalar *)
+ inversion H4; [subst|congruence].
+ assert (b0 = b). congruence. subst b0.
+ assert (chunk0 = chunk). congruence. subst chunk0.
+ assert (storev chunk m2 (Vptr b Int.zero) v = Some m3). assumption.
+ exploit make_store_correct.
+ eapply make_stackaddr_correct.
+ eauto. eauto. eauto. eauto. eauto.
+ rewrite E0_left. intros [tm3 [EVAL [MEMINJ TNEXTBLOCK]]].
+ exists te2; exists tm3.
+ split. auto. split. auto.
+ rewrite NEXTBLOCK; rewrite TNEXTBLOCK.
+ eapply match_callstack_mapped; eauto.
+ inversion H9; congruence.
+ (* var_global_scalar *)
+ inversion H4; [congruence|subst].
+ assert (chunk0 = chunk). congruence. subst chunk0.
+ assert (storev chunk m2 (Vptr b Int.zero) v = Some m3). assumption.
+ assert (match_globalenvs f). eapply match_callstack_match_globalenvs; eauto.
+ inversion H13. destruct (mg_symbols0 _ _ H10) as [A B].
+ exploit make_store_correct.
+ eapply make_globaladdr_correct; eauto.
+ eauto. eauto. eauto. eauto. eauto.
+ rewrite E0_left. intros [tm3 [EVAL [MEMINJ TNEXTBLOCK]]].
+ exists te2; exists tm3.
+ split. auto. split. auto.
+ rewrite NEXTBLOCK; rewrite TNEXTBLOCK.
+ eapply match_callstack_mapped; eauto. congruence.
+Qed.
+
+(** * Correctness of stack allocation of local variables *)
+
+(** This section shows the correctness of the translation of Csharpminor
+ local variables, either as Cminor local variables or as sub-blocks
+ of the Cminor stack data. This is the most difficult part of the proof. *)
+
+Remark assign_variables_incr:
+ forall atk vars cenv sz cenv' sz',
+ assign_variables atk vars (cenv, sz) = (cenv', sz') -> sz <= sz'.
+Proof.
+ induction vars; intros until sz'; simpl.
+ intro. replace sz' with sz. omega. congruence.
+ destruct a. destruct v. case (Identset.mem i atk); intros.
+ generalize (IHvars _ _ _ _ H).
+ generalize (size_chunk_pos m). intro.
+ generalize (align_le sz (size_chunk m) H0). omega.
+ eauto.
+ intro. generalize (IHvars _ _ _ _ H).
+ assert (8 > 0). omega. generalize (align_le sz 8 H0).
+ assert (0 <= Zmax 0 z). apply Zmax_bound_l. omega.
+ omega.
+Qed.
+
+Lemma match_callstack_alloc_variables_rec:
+ forall tm sp cenv' sz' te lo cs atk,
+ valid_block tm sp ->
+ low_bound tm sp = 0 ->
+ high_bound tm sp = sz' ->
+ sz' <= Int.max_signed ->
+ forall e m vars e' m' lb,
+ alloc_variables e m vars e' m' lb ->
+ forall f cenv sz,
+ assign_variables atk vars (cenv, sz) = (cenv', sz') ->
+ match_callstack f (mkframe cenv e te sp lo m.(nextblock) :: cs)
+ m.(nextblock) tm.(nextblock) m ->
+ mem_inject f m tm ->
+ 0 <= sz ->
+ (forall b delta, f b = Some(sp, delta) -> high_bound m b + delta <= sz) ->
+ (forall id lv, In (id, lv) vars -> te!id <> None) ->
+ exists f',
+ inject_incr f f'
+ /\ mem_inject f' m' tm
+ /\ match_callstack f' (mkframe cenv' e' te sp lo m'.(nextblock) :: cs)
+ m'.(nextblock) tm.(nextblock) m'.
+Proof.
+ intros until atk. intros VB LB HB NOOV.
+ induction 1.
+ (* base case *)
+ intros. simpl in H. inversion H; subst cenv sz.
+ exists f. split. apply inject_incr_refl. split. auto. auto.
+ (* inductive case *)
+ intros until sz.
+ change (assign_variables atk ((id, lv) :: vars) (cenv, sz))
+ with (assign_variables atk vars (assign_variable atk (id, lv) (cenv, sz))).
+ caseEq (assign_variable atk (id, lv) (cenv, sz)).
+ intros cenv1 sz1 ASV1 ASVS MATCH MINJ SZPOS BOUND DEFINED.
+ assert (DEFINED1: forall id0 lv0, In (id0, lv0) vars -> te!id0 <> None).
+ intros. eapply DEFINED. simpl. right. eauto.
+ assert (exists tv, te!id = Some tv).
+ assert (te!id <> None). eapply DEFINED. simpl; left; auto.
+ destruct (te!id). exists v; auto. congruence.
+ elim H1; intros tv TEID; clear H1.
+ generalize ASV1. unfold assign_variable.
+ caseEq lv.
+ (* 1. lv = LVscalar chunk *)
+ intros chunk LV. case (Identset.mem id atk).
+ (* 1.1 info = Var_stack_scalar chunk ... *)
+ set (ofs := align sz (size_chunk chunk)).
+ intro EQ; injection EQ; intros; clear EQ.
+ set (f1 := extend_inject b1 (Some (sp, ofs)) f).
+ generalize (size_chunk_pos chunk); intro SIZEPOS.
+ generalize (align_le sz (size_chunk chunk) SIZEPOS). fold ofs. intro SZOFS.
+ assert (mem_inject f1 m1 tm /\ inject_incr f f1).
+ assert (Int.min_signed < 0). compute; auto.
+ generalize (assign_variables_incr _ _ _ _ _ _ ASVS). intro.
+ unfold f1; eapply alloc_mapped_inject; eauto.
+ omega. omega. omega. omega. unfold sizeof; rewrite LV. omega.
+ intros. left. generalize (BOUND _ _ H5). omega.
+ elim H3; intros MINJ1 INCR1; clear H3.
+ exploit IHalloc_variables; eauto.
+ unfold f1; rewrite <- H2; eapply match_callstack_alloc_left; eauto.
+ rewrite <- H1. omega.
+ intros until delta; unfold f1, extend_inject, eq_block.
+ rewrite (high_bound_alloc _ _ b _ _ _ H).
+ case (zeq b b1); intros.
+ inversion H3. unfold sizeof; rewrite LV. omega.
+ generalize (BOUND _ _ H3). omega.
+ intros [f' [INCR2 [MINJ2 MATCH2]]].
+ exists f'; intuition. eapply inject_incr_trans; eauto.
+ (* 1.2 info = Var_local chunk *)
+ intro EQ; injection EQ; intros; clear EQ. subst sz1.
+ exploit alloc_unmapped_inject; eauto.
+ set (f1 := extend_inject b1 None f). intros [MINJ1 INCR1].
+ exploit IHalloc_variables; eauto.
+ unfold f1; rewrite <- H2; eapply match_callstack_alloc_left; eauto.
+ intros until delta; unfold f1, extend_inject, eq_block.
+ rewrite (high_bound_alloc _ _ b _ _ _ H).
+ case (zeq b b1); intros. discriminate.
+ eapply BOUND; eauto.
+ intros [f' [INCR2 [MINJ2 MATCH2]]].
+ exists f'; intuition. eapply inject_incr_trans; eauto.
+ (* 2. lv = LVarray dim, info = Var_stack_array *)
+ intros dim LV EQ. injection EQ; clear EQ; intros.
+ assert (0 <= Zmax 0 dim). apply Zmax1.
+ assert (8 > 0). omega.
+ generalize (align_le sz 8 H4). intro.
+ set (ofs := align sz 8) in *.
+ set (f1 := extend_inject b1 (Some (sp, ofs)) f).
+ assert (mem_inject f1 m1 tm /\ inject_incr f f1).
+ assert (Int.min_signed < 0). compute; auto.
+ generalize (assign_variables_incr _ _ _ _ _ _ ASVS). intro.
+ unfold f1; eapply alloc_mapped_inject; eauto.
+ omega. omega. omega. omega. unfold sizeof; rewrite LV. omega.
+ intros. left. generalize (BOUND _ _ H8). omega.
+ destruct H6 as [MINJ1 INCR1].
+ exploit IHalloc_variables; eauto.
+ unfold f1; rewrite <- H2; eapply match_callstack_alloc_left; eauto.
+ rewrite <- H1. omega.
+ intros until delta; unfold f1, extend_inject, eq_block.
+ rewrite (high_bound_alloc _ _ b _ _ _ H).
+ case (zeq b b1); intros.
+ inversion H6. unfold sizeof; rewrite LV. omega.
+ generalize (BOUND _ _ H6). omega.
+ intros [f' [INCR2 [MINJ2 MATCH2]]].
+ exists f'; intuition. eapply inject_incr_trans; eauto.
+Qed.
+
+Lemma set_params_defined:
+ forall params args id,
+ In id params -> (set_params args params)!id <> None.
+Proof.
+ induction params; simpl; intros.
+ elim H.
+ destruct args.
+ rewrite PTree.gsspec. case (peq id a); intro.
+ congruence. eapply IHparams. elim H; intro. congruence. auto.
+ rewrite PTree.gsspec. case (peq id a); intro.
+ congruence. eapply IHparams. elim H; intro. congruence. auto.
+Qed.
+
+Lemma set_locals_defined:
+ forall e vars id,
+ In id vars \/ e!id <> None -> (set_locals vars e)!id <> None.
+Proof.
+ induction vars; simpl; intros.
+ tauto.
+ rewrite PTree.gsspec. case (peq id a); intro.
+ congruence.
+ apply IHvars. assert (a <> id). congruence. tauto.
+Qed.
+
+Lemma set_locals_params_defined:
+ forall args params vars id,
+ In id (params ++ vars) ->
+ (set_locals vars (set_params args params))!id <> None.
+Proof.
+ intros. apply set_locals_defined.
+ elim (in_app_or _ _ _ H); intro.
+ right. apply set_params_defined; auto.
+ left; auto.
+Qed.
+
+(** Preservation of [match_callstack] by simultaneous allocation
+ of Csharpminor local variables and of the Cminor stack data block. *)
+
+Lemma match_callstack_alloc_variables:
+ forall fn cenv sz m e m' lb tm tm' sp f cs targs,
+ build_compilenv gce fn = (cenv, sz) ->
+ sz <= Int.max_signed ->
+ alloc_variables Csharpminor.empty_env m (fn_variables fn) e m' lb ->
+ Mem.alloc tm 0 sz = (tm', sp) ->
+ match_callstack f cs m.(nextblock) tm.(nextblock) m ->
+ mem_inject f m tm ->
+ let tparams := List.map (@fst ident memory_chunk) fn.(Csharpminor.fn_params) in
+ let tvars := List.map (@fst ident var_kind) fn.(Csharpminor.fn_vars) in
+ let te := set_locals tvars (set_params targs tparams) in
+ exists f',
+ inject_incr f f'
+ /\ mem_inject f' m' tm'
+ /\ match_callstack f' (mkframe cenv e te sp m.(nextblock) m'.(nextblock) :: cs)
+ m'.(nextblock) tm'.(nextblock) m'.
+Proof.
+ intros.
+ assert (SP: sp = nextblock tm). injection H2; auto.
+ unfold build_compilenv in H.
+ eapply match_callstack_alloc_variables_rec with (sz' := sz); eauto.
+ eapply valid_new_block; eauto.
+ rewrite (low_bound_alloc _ _ sp _ _ _ H2). apply zeq_true.
+ rewrite (high_bound_alloc _ _ sp _ _ _ H2). apply zeq_true.
+ (* match_callstack *)
+ constructor. omega. change (valid_block tm' sp). eapply valid_new_block; eauto.
+ constructor.
+ (* me_vars *)
+ intros. generalize (global_compilenv_charact id).
+ destruct (gce!!id); intro; try contradiction.
+ constructor.
+ unfold Csharpminor.empty_env. apply PTree.gempty. auto.
+ constructor.
+ unfold Csharpminor.empty_env. apply PTree.gempty.
+ (* me_low_high *)
+ omega.
+ (* me_bounded *)
+ intros until lv. unfold Csharpminor.empty_env. rewrite PTree.gempty. congruence.
+ (* me_inj *)
+ intros until lv2. unfold Csharpminor.empty_env; rewrite PTree.gempty; congruence.
+ (* me_inv *)
+ intros. exploit mi_mappedblocks; eauto. intros [A B].
+ elim (fresh_block_alloc _ _ _ _ _ H2 A).
+ (* me_incr *)
+ intros. exploit mi_mappedblocks; eauto. intros [A B].
+ rewrite SP; auto.
+ rewrite SP; auto.
+ eapply alloc_right_inject; eauto.
+ omega.
+ intros. exploit mi_mappedblocks; eauto. intros [A B].
+ unfold block in SP; omegaContradiction.
+ (* defined *)
+ intros. unfold te. apply set_locals_params_defined.
+ unfold tparams, tvars. unfold fn_variables in H5.
+ change Csharpminor.fn_params with Csharpminor.fn_params in H5.
+ change Csharpminor.fn_vars with Csharpminor.fn_vars in H5.
+ elim (in_app_or _ _ _ H5); intros.
+ elim (list_in_map_inv _ _ _ H6). intros x [A B].
+ apply in_or_app; left. inversion A. apply List.in_map. auto.
+ apply in_or_app; right.
+ change id with (fst (id, lv)). apply List.in_map; auto.
+Qed.
+
+(** Characterization of the range of addresses for the blocks allocated
+ to hold Csharpminor local variables. *)
+
+Lemma alloc_variables_nextblock_incr:
+ forall e1 m1 vars e2 m2 lb,
+ alloc_variables e1 m1 vars e2 m2 lb ->
+ nextblock m1 <= nextblock m2.
+Proof.
+ induction 1; intros.
+ omega.
+ inversion H; subst m1; simpl in IHalloc_variables. omega.
+Qed.
+
+Lemma alloc_variables_list_block:
+ forall e1 m1 vars e2 m2 lb,
+ alloc_variables e1 m1 vars e2 m2 lb ->
+ forall b, m1.(nextblock) <= b < m2.(nextblock) <-> In b lb.
+Proof.
+ induction 1; intros.
+ simpl; split; intro. omega. contradiction.
+ elim (IHalloc_variables b); intros A B.
+ assert (nextblock m = b1). injection H; intros. auto.
+ assert (nextblock m1 = Zsucc (nextblock m)).
+ injection H; intros; subst m1; reflexivity.
+ simpl; split; intro.
+ assert (nextblock m = b \/ nextblock m1 <= b < nextblock m2).
+ unfold block; rewrite H2; omega.
+ elim H4; intro. left; congruence. right; auto.
+ elim H3; intro. subst b b1.
+ generalize (alloc_variables_nextblock_incr _ _ _ _ _ _ H0).
+ rewrite H2. omega.
+ generalize (B H4). rewrite H2. omega.
+Qed.
+
+(** Correctness of the code generated by [store_parameters]
+ to store in memory the values of parameters that are stack-allocated. *)
+
+Inductive vars_vals_match:
+ meminj -> list (ident * memory_chunk) -> list val -> env -> Prop :=
+ | vars_vals_nil:
+ forall f te,
+ vars_vals_match f nil nil te
+ | vars_vals_cons:
+ forall f te id chunk vars v vals tv,
+ te!id = Some tv ->
+ val_inject f v tv ->
+ vars_vals_match f vars vals te ->
+ vars_vals_match f ((id, chunk) :: vars) (v :: vals) te.
+
+Lemma vars_vals_match_extensional:
+ forall f vars vals te,
+ vars_vals_match f vars vals te ->
+ forall te',
+ (forall id lv, In (id, lv) vars -> te'!id = te!id) ->
+ vars_vals_match f vars vals te'.
+Proof.
+ induction 1; intros.
+ constructor.
+ econstructor; eauto. rewrite <- H. eapply H2. left. reflexivity.
+ apply IHvars_vals_match. intros. eapply H2; eauto. right. eauto.
+Qed.
+
+Lemma store_parameters_correct:
+ forall e m1 params vl m2,
+ bind_parameters e m1 params vl m2 ->
+ forall f te1 cenv sp lo hi cs tm1,
+ vars_vals_match f params vl te1 ->
+ list_norepet (List.map (@fst ident memory_chunk) params) ->
+ mem_inject f m1 tm1 ->
+ match_callstack f (mkframe cenv e te1 sp lo hi :: cs) m1.(nextblock) tm1.(nextblock) m1 ->
+ exists te2, exists tm2,
+ exec_stmt tge (Vptr sp Int.zero)
+ te1 tm1 (store_parameters cenv params)
+ E0 te2 tm2 Out_normal
+ /\ mem_inject f m2 tm2
+ /\ match_callstack f (mkframe cenv e te2 sp lo hi :: cs) m2.(nextblock) tm2.(nextblock) m2.
+Proof.
+ induction 1.
+ (* base case *)
+ intros; simpl. exists te1; exists tm1. split. constructor. tauto.
+ (* inductive case *)
+ intros until tm1. intros VVM NOREPET MINJ MATCH. simpl.
+ inversion VVM. subst f0 id0 chunk0 vars v vals te.
+ inversion MATCH. subst f0 cenv0 e0 te sp0 lo0 hi0 cs0 bound tbound m0.
+ inversion H18.
+ inversion NOREPET. subst hd tl.
+ assert (NEXT: nextblock m1 = nextblock m).
+ exploit store_inv; eauto. simpl; tauto.
+ generalize (me_vars0 id). intro. inversion H2; subst.
+ (* cenv!!id = Var_local chunk *)
+ assert (b0 = b). congruence. subst b0.
+ assert (chunk0 = chunk). congruence. subst chunk0.
+ assert (v' = tv). congruence. subst v'.
+ exploit make_cast_correct.
+ apply eval_Evar with (id := id). eauto.
+ eexact H10.
+ intros [tv' [EVAL1 VINJ1]].
+ set (te2 := PTree.set id tv' te1).
+ assert (VVM2: vars_vals_match f params vl te2).
+ apply vars_vals_match_extensional with te1; auto.
+ intros. unfold te2; apply PTree.gso. red; intro; subst id0.
+ elim H4. change id with (fst (id, lv)). apply List.in_map; auto.
+ exploit store_unmapped_inject; eauto. intro MINJ2.
+ exploit match_callstack_store_local; eauto.
+ fold te2; rewrite <- NEXT; intro MATCH2.
+ exploit IHbind_parameters; eauto.
+ intros [te3 [tm3 [EXEC3 [MINJ3 MATCH3]]]].
+ exists te3; exists tm3.
+ (* execution *)
+ split. apply exec_Sseq_continue with E0 te2 tm1 E0.
+ econstructor. unfold te2. constructor. eassumption.
+ assumption. traceEq.
+ (* meminj & match_callstack *)
+ tauto.
+
+ (* cenv!!id = Var_stack_scalar *)
+ assert (b0 = b). congruence. subst b0.
+ assert (chunk0 = chunk). congruence. subst chunk0.
+ exploit make_store_correct.
+ eapply make_stackaddr_correct.
+ apply eval_Evar with (id := id).
+ eauto. 2:eauto. 2:eauto. unfold storev; eexact H0. eauto.
+ intros [tm2 [EVAL3 [MINJ2 NEXT1]]].
+ exploit match_callstack_mapped.
+ eexact MATCH. 2:eauto. inversion H7. congruence.
+ rewrite <- NEXT; rewrite <- NEXT1; intro MATCH2.
+ exploit IHbind_parameters; eauto.
+ intros [te3 [tm3 [EVAL4 [MINJ3 MATCH3]]]].
+ exists te3; exists tm3.
+ (* execution *)
+ split. apply exec_Sseq_continue with (E0**E0) te1 tm2 E0.
+ auto. assumption. traceEq.
+ (* meminj & match_callstack *)
+ tauto.
+
+ (* Impossible cases on cenv!!id *)
+ congruence.
+ congruence.
+ congruence.
+Qed.
+
+Lemma vars_vals_match_holds_1:
+ forall f params args targs,
+ list_norepet (List.map (@fst ident memory_chunk) params) ->
+ List.length params = List.length args ->
+ val_list_inject f args targs ->
+ vars_vals_match f params args
+ (set_params targs (List.map (@fst ident memory_chunk) params)).
+Proof.
+ induction params; destruct args; simpl; intros; try discriminate.
+ constructor.
+ inversion H1. subst v0 vl targs.
+ inversion H. subst hd tl.
+ destruct a as [id chunk]. econstructor.
+ simpl. rewrite PTree.gss. reflexivity.
+ auto.
+ apply vars_vals_match_extensional
+ with (set_params vl' (map (@fst ident memory_chunk) params)).
+ eapply IHparams; eauto.
+ intros. simpl. apply PTree.gso. red; intro; subst id0.
+ elim H5. change (fst (id, chunk)) with (fst (id, lv)).
+ apply List.in_map; auto.
+Qed.
+
+Lemma vars_vals_match_holds:
+ forall f params args targs,
+ List.length params = List.length args ->
+ val_list_inject f args targs ->
+ forall vars,
+ list_norepet (List.map (@fst ident var_kind) vars
+ ++ List.map (@fst ident memory_chunk) params) ->
+ vars_vals_match f params args
+ (set_locals (List.map (@fst ident var_kind) vars)
+ (set_params targs (List.map (@fst ident memory_chunk) params))).
+Proof.
+ induction vars; simpl; intros.
+ eapply vars_vals_match_holds_1; eauto.
+ inversion H1. subst hd tl.
+ eapply vars_vals_match_extensional; eauto.
+ intros. apply PTree.gso. red; intro; subst id; elim H4.
+ apply in_or_app. right. change (fst a) with (fst (fst a, lv)).
+ apply List.in_map; auto.
+Qed.
+
+Lemma bind_parameters_length:
+ forall e m1 params args m2,
+ bind_parameters e m1 params args m2 ->
+ List.length params = List.length args.
+Proof.
+ induction 1; simpl; eauto.
+Qed.
+
+(** The final result in this section: the behaviour of function entry
+ in the generated Cminor code (allocate stack data block and store
+ parameters whose address is taken) simulates what happens at function
+ entry in the original Csharpminor (allocate one block per local variable
+ and initialize the blocks corresponding to function parameters). *)
+
+Lemma function_entry_ok:
+ forall fn m e m1 lb vargs m2 f cs tm cenv sz tm1 sp tvargs,
+ alloc_variables empty_env m (fn_variables fn) e m1 lb ->
+ bind_parameters e m1 fn.(Csharpminor.fn_params) vargs m2 ->
+ match_callstack f cs m.(nextblock) tm.(nextblock) m ->
+ build_compilenv gce fn = (cenv, sz) ->
+ sz <= Int.max_signed ->
+ Mem.alloc tm 0 sz = (tm1, sp) ->
+ let te :=
+ set_locals (fn_vars_names fn) (set_params tvargs (fn_params_names fn)) in
+ val_list_inject f vargs tvargs ->
+ mem_inject f m tm ->
+ list_norepet (fn_params_names fn ++ fn_vars_names fn) ->
+ exists f2, exists te2, exists tm2,
+ exec_stmt tge (Vptr sp Int.zero)
+ te tm1 (store_parameters cenv fn.(Csharpminor.fn_params))
+ E0 te2 tm2 Out_normal
+ /\ mem_inject f2 m2 tm2
+ /\ inject_incr f f2
+ /\ match_callstack f2
+ (mkframe cenv e te2 sp m.(nextblock) m1.(nextblock) :: cs)
+ m2.(nextblock) tm2.(nextblock) m2
+ /\ (forall b, m.(nextblock) <= b < m1.(nextblock) <-> In b lb).
+Proof.
+ intros.
+ exploit bind_parameters_length; eauto. intro LEN1.
+ exploit match_callstack_alloc_variables; eauto.
+ intros [f1 [INCR1 [MINJ1 MATCH1]]].
+ exploit vars_vals_match_holds.
+ eauto. apply val_list_inject_incr with f. eauto. eauto.
+ apply list_norepet_append_commut.
+ unfold fn_vars_names in H7. eexact H7.
+ intro VVM.
+ exploit store_parameters_correct.
+ eauto. eauto.
+ unfold fn_params_names in H7. eapply list_norepet_append_left; eauto.
+ eexact MINJ1. eauto.
+ intros [te2 [tm2 [EXEC [MINJ2 MATCH2]]]].
+ exists f1; exists te2; exists tm2.
+ split; auto. split; auto. split; auto. split; auto.
+ intros; eapply alloc_variables_list_block; eauto.
+Qed.
+
+(** * Semantic preservation for the translation *)
+
+(** These tactics simplify hypotheses of the form [f ... = Some x]. *)
+
+Ltac monadSimpl1 :=
+ match goal with
+ | [ |- (bind _ _ ?F ?G = Some ?X) -> _ ] =>
+ unfold bind at 1;
+ generalize (refl_equal F);
+ pattern F at -1 in |- *;
+ case F;
+ [ (let EQ := fresh "EQ" in
+ (intro; intro EQ;
+ try monadSimpl1))
+ | intros; discriminate ]
+ | [ |- (None = Some _) -> _ ] =>
+ intro; discriminate
+ | [ |- (Some _ = Some _) -> _ ] =>
+ let h := fresh "H" in
+ (intro h; injection h; intro; clear h)
+ end.
+
+Ltac monadSimpl :=
+ match goal with
+ | [ |- (bind _ _ ?F ?G = Some ?X) -> _ ] => monadSimpl1
+ | [ |- (None = Some _) -> _ ] => monadSimpl1
+ | [ |- (Some _ = Some _) -> _ ] => monadSimpl1
+ | [ |- (?F _ _ _ _ _ _ _ = Some _) -> _ ] => simpl F; monadSimpl1
+ | [ |- (?F _ _ _ _ _ _ = Some _) -> _ ] => simpl F; monadSimpl1
+ | [ |- (?F _ _ _ _ _ = Some _) -> _ ] => simpl F; monadSimpl1
+ | [ |- (?F _ _ _ _ = Some _) -> _ ] => simpl F; monadSimpl1
+ | [ |- (?F _ _ _ = Some _) -> _ ] => simpl F; monadSimpl1
+ | [ |- (?F _ _ = Some _) -> _ ] => simpl F; monadSimpl1
+ | [ |- (?F _ = Some _) -> _ ] => simpl F; monadSimpl1
+ end.
+
+Ltac monadInv H :=
+ generalize H; monadSimpl.
+
+(** The proof of semantic preservation uses simulation diagrams of the
+ following form:
+<<
+ le, e, m1, a --------------- tle, sp, te1, tm1, ta
+ | |
+ | |
+ v v
+ le, e, m2, v --------------- tle, sp, te2, tm2, tv
+>>
+ where [ta] is the Cminor expression obtained by translating the
+ Csharpminor expression [a]. The left vertical arrow is an evaluation
+ of a Csharpminor expression. The right vertical arrow is an evaluation
+ of a Cminor expression. The precondition (top vertical bar)
+ includes a [mem_inject] relation between the memory states [m1] and [tm1],
+ a [val_list_inject] relation between the let environments [le] and [tle],
+ and a [match_callstack] relation for any callstack having
+ [e], [te1], [sp] as top frame. The postcondition (bottom vertical bar)
+ is the existence of a memory injection [f2] that extends the injection
+ [f1] we started with, preserves the [match_callstack] relation for
+ the transformed callstack at the final state, and validates a
+ [val_inject] relation between the result values [v] and [tv].
+
+ We capture these diagrams by the following predicates, parameterized
+ over the Csharpminor executions, which will serve as induction
+ hypotheses in the proof of simulation. *)
+
+Definition eval_expr_prop
+ (le: Csharpminor.letenv) (e: Csharpminor.env) (m1: mem) (a: Csharpminor.expr) (t: trace) (m2: mem) (v: val) : Prop :=
+ forall cenv ta f1 tle te1 tm1 sp lo hi cs
+ (TR: transl_expr cenv a = Some ta)
+ (LINJ: val_list_inject f1 le tle)
+ (MINJ: mem_inject f1 m1 tm1)
+ (MATCH: match_callstack f1
+ (mkframe cenv e te1 sp lo hi :: cs)
+ m1.(nextblock) tm1.(nextblock) m1),
+ exists f2, exists te2, exists tm2, exists tv,
+ eval_expr tge (Vptr sp Int.zero) tle te1 tm1 ta t te2 tm2 tv
+ /\ val_inject f2 v tv
+ /\ mem_inject f2 m2 tm2
+ /\ inject_incr f1 f2
+ /\ match_callstack f2
+ (mkframe cenv e te2 sp lo hi :: cs)
+ m2.(nextblock) tm2.(nextblock) m2.
+
+Definition eval_exprlist_prop
+ (le: Csharpminor.letenv) (e: Csharpminor.env) (m1: mem) (al: Csharpminor.exprlist) (t: trace) (m2: mem) (vl: list val) : Prop :=
+ forall cenv tal f1 tle te1 tm1 sp lo hi cs
+ (TR: transl_exprlist cenv al = Some tal)
+ (LINJ: val_list_inject f1 le tle)
+ (MINJ: mem_inject f1 m1 tm1)
+ (MATCH: match_callstack f1
+ (mkframe cenv e te1 sp lo hi :: cs)
+ m1.(nextblock) tm1.(nextblock) m1),
+ exists f2, exists te2, exists tm2, exists tvl,
+ eval_exprlist tge (Vptr sp Int.zero) tle te1 tm1 tal t te2 tm2 tvl
+ /\ val_list_inject f2 vl tvl
+ /\ mem_inject f2 m2 tm2
+ /\ inject_incr f1 f2
+ /\ match_callstack f2
+ (mkframe cenv e te2 sp lo hi :: cs)
+ m2.(nextblock) tm2.(nextblock) m2.
+
+Definition eval_funcall_prop
+ (m1: mem) (fn: Csharpminor.fundef) (args: list val) (t: trace) (m2: mem) (res: val) : Prop :=
+ forall tfn f1 tm1 cs targs
+ (TR: transl_fundef gce fn = Some tfn)
+ (MINJ: mem_inject f1 m1 tm1)
+ (MATCH: match_callstack f1 cs m1.(nextblock) tm1.(nextblock) m1)
+ (ARGSINJ: val_list_inject f1 args targs),
+ exists f2, exists tm2, exists tres,
+ eval_funcall tge tm1 tfn targs t tm2 tres
+ /\ val_inject f2 res tres
+ /\ mem_inject f2 m2 tm2
+ /\ inject_incr f1 f2
+ /\ match_callstack f2 cs m2.(nextblock) tm2.(nextblock) m2.
+
+Inductive outcome_inject (f: meminj) : Csharpminor.outcome -> outcome -> Prop :=
+ | outcome_inject_normal:
+ outcome_inject f Csharpminor.Out_normal Out_normal
+ | outcome_inject_exit:
+ forall n, outcome_inject f (Csharpminor.Out_exit n) (Out_exit n)
+ | outcome_inject_return_none:
+ outcome_inject f (Csharpminor.Out_return None) (Out_return None)
+ | outcome_inject_return_some:
+ forall v1 v2,
+ val_inject f v1 v2 ->
+ outcome_inject f (Csharpminor.Out_return (Some v1)) (Out_return (Some v2)).
+
+Definition exec_stmt_prop
+ (e: Csharpminor.env) (m1: mem) (s: Csharpminor.stmt) (t: trace) (m2: mem) (out: Csharpminor.outcome): Prop :=
+ forall cenv ts f1 te1 tm1 sp lo hi cs
+ (TR: transl_stmt cenv s = Some ts)
+ (MINJ: mem_inject f1 m1 tm1)
+ (MATCH: match_callstack f1
+ (mkframe cenv e te1 sp lo hi :: cs)
+ m1.(nextblock) tm1.(nextblock) m1),
+ exists f2, exists te2, exists tm2, exists tout,
+ exec_stmt tge (Vptr sp Int.zero) te1 tm1 ts t te2 tm2 tout
+ /\ outcome_inject f2 out tout
+ /\ mem_inject f2 m2 tm2
+ /\ inject_incr f1 f2
+ /\ match_callstack f2
+ (mkframe cenv e te2 sp lo hi :: cs)
+ m2.(nextblock) tm2.(nextblock) m2.
+
+(** There are as many cases in the inductive proof as there are evaluation
+ rules in the Csharpminor semantics. We treat each case as a separate
+ lemma. *)
+
+Lemma transl_expr_Evar_correct:
+ forall (le : Csharpminor.letenv)
+ (e : Csharpminor.env) (m : mem) (id : positive)
+ (b : block) (chunk : memory_chunk) (v : val),
+ eval_var_ref prog e id b chunk ->
+ load chunk m b 0 = Some v ->
+ eval_expr_prop le e m (Csharpminor.Evar id) E0 m v.
+Proof.
+ intros; red; intros. unfold transl_expr in TR.
+ exploit var_get_correct; eauto.
+ intros [tv [EVAL VINJ]].
+ exists f1; exists te1; exists tm1; exists tv; intuition eauto.
+Qed.
+
+Lemma transl_expr_Eaddrof_correct:
+ forall (le : Csharpminor.letenv)
+ (e : Csharpminor.env) (m : mem) (id : positive)
+ (b : block),
+ eval_var_addr prog e id b ->
+ eval_expr_prop le e m (Eaddrof id) E0 m (Vptr b Int.zero).
+Proof.
+ intros; red; intros. simpl in TR.
+ exploit var_addr_correct; eauto.
+ intros [tv [EVAL VINJ]].
+ exists f1; exists te1; exists tm1; exists tv. intuition eauto.
+Qed.
+
+Lemma transl_expr_Eop_correct:
+ forall (le : Csharpminor.letenv) (e : Csharpminor.env) (m : mem)
+ (op : Csharpminor.operation) (al : Csharpminor.exprlist)
+ (t: trace) (m1 : mem) (vl : list val) (v : val),
+ Csharpminor.eval_exprlist prog le e m al t m1 vl ->
+ eval_exprlist_prop le e m al t m1 vl ->
+ Csharpminor.eval_operation op vl m1 = Some v ->
+ eval_expr_prop le e m (Csharpminor.Eop op al) t m1 v.
+Proof.
+ intros; red; intros. monadInv TR; intro EQ0.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tvl [EVAL1 [VINJ1 [MINJ1 [INCR1 MATCH1]]]]]]]].
+ exploit make_op_correct; eauto.
+ intros [tv [EVAL2 VINJ2]].
+ exists f2; exists te2; exists tm2; exists tv. intuition.
+Qed.
+
+Lemma transl_expr_Eload_correct:
+ forall (le : Csharpminor.letenv) (e : Csharpminor.env) (m : mem)
+ (chunk : memory_chunk) (a : Csharpminor.expr) (t: trace) (m1 : mem)
+ (v1 v : val),
+ Csharpminor.eval_expr prog le e m a t m1 v1 ->
+ eval_expr_prop le e m a t m1 v1 ->
+ loadv chunk m1 v1 = Some v ->
+ eval_expr_prop le e m (Csharpminor.Eload chunk a) t m1 v.
+Proof.
+ intros; red; intros.
+ monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL [VINJ1 [MINJ2 [INCR MATCH2]]]]]]]].
+ exploit loadv_inject; eauto.
+ intros [tv [TLOAD VINJ]].
+ exists f2; exists te2; exists tm2; exists tv.
+ intuition.
+ subst ta. eapply make_load_correct; eauto.
+Qed.
+
+Lemma transl_expr_Ecall_correct:
+ forall (le : Csharpminor.letenv) (e : Csharpminor.env) (m : mem)
+ (sig : signature) (a : Csharpminor.expr) (bl : Csharpminor.exprlist)
+ (t1: trace) (m1: mem) (t2: trace) (m2: mem) (t3: trace) (m3: mem)
+ (vf : val) (vargs : list val) (vres : val)
+ (f : Csharpminor.fundef) (t: trace),
+ Csharpminor.eval_expr prog le e m a t1 m1 vf ->
+ eval_expr_prop le e m a t1 m1 vf ->
+ Csharpminor.eval_exprlist prog le e m1 bl t2 m2 vargs ->
+ eval_exprlist_prop le e m1 bl t2 m2 vargs ->
+ Genv.find_funct ge vf = Some f ->
+ Csharpminor.funsig f = sig ->
+ Csharpminor.eval_funcall prog m2 f vargs t3 m3 vres ->
+ eval_funcall_prop m2 f vargs t3 m3 vres ->
+ t = t1 ** t2 ** t3 ->
+ eval_expr_prop le e m (Csharpminor.Ecall sig a bl) t m3 vres.
+Proof.
+ intros;red;intros. monadInv TR. subst ta.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL1 [VINJ1 [MINJ1 [INCR1 MATCH1]]]]]]]].
+ exploit H2.
+ eauto. eapply val_list_inject_incr; eauto. eauto. eauto.
+ intros [f3 [te3 [tm3 [tv2 [EVAL2 [VINJ2 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ assert (tv1 = vf).
+ elim (Genv.find_funct_inv H3). intros bf VF. rewrite VF in H3.
+ rewrite Genv.find_funct_find_funct_ptr in H3.
+ generalize (Genv.find_funct_ptr_inv H3). intro.
+ assert (match_globalenvs f2). eapply match_callstack_match_globalenvs; eauto.
+ generalize (mg_functions _ H9 _ H8). intro.
+ rewrite VF in VINJ1. inversion VINJ1. subst vf.
+ decEq. congruence.
+ subst ofs2. replace x with 0. reflexivity. congruence.
+ subst tv1. elim (functions_translated _ _ H3). intros tf [FIND TRF].
+ exploit H6; eauto.
+ intros [f4 [tm4 [tres [EVAL3 [VINJ3 [MINJ3 [INCR3 MATCH3]]]]]]].
+ exists f4; exists te3; exists tm4; exists tres. intuition.
+ eapply eval_Ecall; eauto.
+ rewrite <- H4. apply sig_preserved; auto.
+ apply inject_incr_trans with f2; auto.
+ apply inject_incr_trans with f3; auto.
+Qed.
+
+Lemma transl_expr_Econdition_true_correct:
+ forall (le : Csharpminor.letenv) (e : Csharpminor.env) (m : mem)
+ (a b c : Csharpminor.expr) (t1: trace) (m1 : mem) (v1 : val)
+ (t2: trace) (m2 : mem) (v2 : val) (t: trace),
+ Csharpminor.eval_expr prog le e m a t1 m1 v1 ->
+ eval_expr_prop le e m a t1 m1 v1 ->
+ Val.is_true v1 ->
+ Csharpminor.eval_expr prog le e m1 b t2 m2 v2 ->
+ eval_expr_prop le e m1 b t2 m2 v2 ->
+ t = t1 ** t2 ->
+ eval_expr_prop le e m (Csharpminor.Econdition a b c) t m2 v2.
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL1 [VINJ1 [MINJ1 [INCR1 MATCH1]]]]]]]].
+ exploit H3.
+ eauto. eapply val_list_inject_incr; eauto. eauto. eauto.
+ intros [f3 [te3 [tm3 [tv2 [EVAL2 [VINJ2 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ exists f3; exists te3; exists tm3; exists tv2.
+ intuition.
+ rewrite <- H6. subst t; eapply eval_conditionalexpr_true; eauto.
+ inversion VINJ1; subst v1 tv1; simpl in H1; simpl; contradiction || auto.
+ eapply inject_incr_trans; eauto.
+Qed.
+
+Lemma transl_expr_Econdition_false_correct:
+ forall (le : Csharpminor.letenv) (e : Csharpminor.env) (m : mem)
+ (a b c : Csharpminor.expr) (t1: trace) (m1 : mem) (v1 : val)
+ (t2: trace) (m2 : mem) (v2 : val) (t: trace),
+ Csharpminor.eval_expr prog le e m a t1 m1 v1 ->
+ eval_expr_prop le e m a t1 m1 v1 ->
+ Val.is_false v1 ->
+ Csharpminor.eval_expr prog le e m1 c t2 m2 v2 ->
+ eval_expr_prop le e m1 c t2 m2 v2 ->
+ t = t1 ** t2 ->
+ eval_expr_prop le e m (Csharpminor.Econdition a b c) t m2 v2.
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL1 [VINJ1 [MINJ1 [INCR1 MATCH1]]]]]]]].
+ exploit H3.
+ eauto. eapply val_list_inject_incr; eauto. eauto. eauto.
+ intros [f3 [te3 [tm3 [tv2 [EVAL2 [VINJ2 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ exists f3; exists te3; exists tm3; exists tv2.
+ intuition.
+ rewrite <- H6. subst t; eapply eval_conditionalexpr_false; eauto.
+ inversion VINJ1; subst v1 tv1; simpl in H1; simpl; contradiction || auto.
+ eapply inject_incr_trans; eauto.
+Qed.
+
+Lemma transl_expr_Elet_correct:
+ forall (le : Csharpminor.letenv) (e : Csharpminor.env) (m : mem)
+ (a b : Csharpminor.expr) (t1: trace) (m1 : mem) (v1 : val)
+ (t2: trace) (m2 : mem) (v2 : val) (t: trace),
+ Csharpminor.eval_expr prog le e m a t1 m1 v1 ->
+ eval_expr_prop le e m a t1 m1 v1 ->
+ Csharpminor.eval_expr prog (v1 :: le) e m1 b t2 m2 v2 ->
+ eval_expr_prop (v1 :: le) e m1 b t2 m2 v2 ->
+ t = t1 ** t2 ->
+ eval_expr_prop le e m (Csharpminor.Elet a b) t m2 v2.
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL1 [VINJ1 [MINJ1 [INCR1 MATCH1]]]]]]]].
+ exploit H2.
+ eauto.
+ constructor. eauto. eapply val_list_inject_incr; eauto.
+ eauto. eauto.
+ intros [f3 [te3 [tm3 [tv2 [EVAL2 [VINJ2 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ exists f3; exists te3; exists tm3; exists tv2.
+ intuition.
+ subst ta; eapply eval_Elet; eauto.
+ eapply inject_incr_trans; eauto.
+Qed.
+
+Remark val_list_inject_nth:
+ forall f l1 l2, val_list_inject f l1 l2 ->
+ forall n v1, nth_error l1 n = Some v1 ->
+ exists v2, nth_error l2 n = Some v2 /\ val_inject f v1 v2.
+Proof.
+ induction 1; destruct n; simpl; intros.
+ discriminate. discriminate.
+ injection H1; intros; subst v. exists v'; split; auto.
+ eauto.
+Qed.
+
+Lemma transl_expr_Eletvar_correct:
+ forall (le : list val) (e : Csharpminor.env) (m : mem) (n : nat)
+ (v : val),
+ nth_error le n = Some v ->
+ eval_expr_prop le e m (Csharpminor.Eletvar n) E0 m v.
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit val_list_inject_nth; eauto. intros [tv [A B]].
+ exists f1; exists te1; exists tm1; exists tv.
+ intuition.
+ subst ta. eapply eval_Eletvar; auto.
+Qed.
+
+Lemma transl_expr_Ealloc_correct:
+ forall (le: list val) (e: Csharpminor.env) (m1: mem) (a: Csharpminor.expr)
+ (t: trace) (m2: mem) (n: int) (m3: mem) (b: block),
+ Csharpminor.eval_expr prog le e m1 a t m2 (Vint n) ->
+ eval_expr_prop le e m1 a t m2 (Vint n) ->
+ Mem.alloc m2 0 (Int.signed n) = (m3, b) ->
+ eval_expr_prop le e m1 (Csharpminor.Ealloc a) t m3 (Vptr b Int.zero).
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL1 [VINJ1 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ inversion VINJ1. subst tv1 i.
+ caseEq (alloc tm2 0 (Int.signed n)). intros tm3 tb TALLOC.
+ assert (LB: Int.min_signed <= 0). compute. congruence.
+ assert (HB: Int.signed n <= Int.max_signed).
+ generalize (Int.signed_range n); omega.
+ exploit alloc_parallel_inject; eauto.
+ intros [MINJ3 INCR3].
+ exists (extend_inject b (Some (tb, 0)) f2);
+ exists te2; exists tm3; exists (Vptr tb Int.zero).
+ split. subst ta; econstructor; eauto.
+ split. econstructor. unfold extend_inject, eq_block. rewrite zeq_true. reflexivity.
+ reflexivity.
+ split. assumption.
+ split. eapply inject_incr_trans; eauto.
+ eapply match_callstack_alloc; eauto.
+Qed.
+
+Lemma transl_exprlist_Enil_correct:
+ forall (le : Csharpminor.letenv) (e : Csharpminor.env) (m : mem),
+ eval_exprlist_prop le e m Csharpminor.Enil E0 m nil.
+Proof.
+ intros; red; intros. monadInv TR.
+ exists f1; exists te1; exists tm1; exists (@nil val).
+ intuition. subst tal; constructor.
+Qed.
+
+Lemma transl_exprlist_Econs_correct:
+ forall (le : Csharpminor.letenv) (e : Csharpminor.env) (m : mem)
+ (a : Csharpminor.expr) (bl : Csharpminor.exprlist)
+ (t1: trace) (m1 : mem) (v : val)
+ (t2: trace) (m2 : mem) (vl : list val) (t: trace),
+ Csharpminor.eval_expr prog le e m a t1 m1 v ->
+ eval_expr_prop le e m a t1 m1 v ->
+ Csharpminor.eval_exprlist prog le e m1 bl t2 m2 vl ->
+ eval_exprlist_prop le e m1 bl t2 m2 vl ->
+ t = t1 ** t2 ->
+ eval_exprlist_prop le e m (Csharpminor.Econs a bl) t m2 (v :: vl).
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL1 [VINJ1 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ exploit H2.
+ eauto. eapply val_list_inject_incr; eauto. eauto. eauto.
+ intros [f3 [te3 [tm3 [tv2 [EVAL2 [VINJ2 [MINJ3 [INCR3 MATCH3]]]]]]]].
+ exists f3; exists te3; exists tm3; exists (tv1 :: tv2).
+ intuition. subst tal; econstructor; eauto.
+ constructor. eapply val_inject_incr; eauto. auto.
+ eapply inject_incr_trans; eauto.
+Qed.
+
+Lemma transl_funcall_internal_correct:
+ forall (m : mem) (f : Csharpminor.function) (vargs : list val)
+ (e : Csharpminor.env) (m1 : mem) (lb : list block) (m2: mem)
+ (t: trace) (m3 : mem) (out : Csharpminor.outcome) (vres : val),
+ list_norepet (fn_params_names f ++ fn_vars_names f) ->
+ alloc_variables empty_env m (fn_variables f) e m1 lb ->
+ bind_parameters e m1 (Csharpminor.fn_params f) vargs m2 ->
+ Csharpminor.exec_stmt prog e m2 (Csharpminor.fn_body f) t m3 out ->
+ exec_stmt_prop e m2 (Csharpminor.fn_body f) t m3 out ->
+ Csharpminor.outcome_result_value out (sig_res (Csharpminor.fn_sig f)) vres ->
+ eval_funcall_prop m (Internal f) vargs t (free_list m3 lb) vres.
+Proof.
+ intros; red. intros tfn f1 tm; intros.
+ generalize TR; clear TR.
+ unfold transl_fundef, transf_partial_fundef.
+ caseEq (transl_function gce f); try congruence.
+ intros tf TR EQ. inversion EQ; clear EQ; subst tfn.
+ unfold transl_function in TR.
+ caseEq (build_compilenv gce f); intros cenv stacksize CENV.
+ rewrite CENV in TR.
+ destruct (zle stacksize Int.max_signed); try discriminate.
+ monadInv TR. clear TR.
+ caseEq (alloc tm 0 stacksize). intros tm1 sp ALLOC.
+ exploit function_entry_ok; eauto.
+ intros [f2 [te2 [tm2 [STOREPARAM [MINJ2 [INCR12 [MATCH2 BLOCKS]]]]]]].
+ red in H3; exploit H3; eauto.
+ intros [f3 [te3 [tm3 [tout [EXECBODY [OUTINJ [MINJ3 [INCR23 MATCH3]]]]]]]].
+ assert (exists tvres,
+ outcome_result_value tout f.(Csharpminor.fn_sig).(sig_res) tvres /\
+ val_inject f3 vres tvres).
+ generalize H4. unfold Csharpminor.outcome_result_value, outcome_result_value.
+ inversion OUTINJ.
+ destruct (sig_res (Csharpminor.fn_sig f)); intro. contradiction.
+ exists Vundef; split. auto. subst vres; constructor.
+ tauto.
+ destruct (sig_res (Csharpminor.fn_sig f)); intro. contradiction.
+ exists Vundef; split. auto. subst vres; constructor.
+ destruct (sig_res (Csharpminor.fn_sig f)); intro.
+ exists v2; split. auto. subst vres; auto.
+ contradiction.
+ destruct H5 as [tvres [TOUT VINJRES]].
+ exists f3; exists (Mem.free tm3 sp); exists tvres.
+ (* execution *)
+ split. rewrite <- H6; econstructor; simpl; eauto.
+ apply exec_Sseq_continue with E0 te2 tm2 t.
+ exact STOREPARAM.
+ eexact EXECBODY.
+ traceEq.
+ (* val_inject *)
+ split. assumption.
+ (* mem_inject *)
+ split. apply free_inject; auto.
+ intros. elim (BLOCKS b1); intros B1 B2. apply B1. inversion MATCH3. inversion H20.
+ eapply me_inv0. eauto.
+ (* inject_incr *)
+ split. eapply inject_incr_trans; eauto.
+ (* match_callstack *)
+ assert (forall bl mm, nextblock (free_list mm bl) = nextblock mm).
+ induction bl; intros. reflexivity. simpl. auto.
+ unfold free; simpl nextblock. rewrite H5.
+ eapply match_callstack_freelist; eauto.
+ intros. elim (BLOCKS b); intros B1 B2. generalize (B2 H7). omega.
+Qed.
+
+Lemma transl_funcall_external_correct:
+ forall (m : mem) (ef : external_function) (vargs : list val)
+ (t : trace) (vres : val),
+ event_match ef vargs t vres ->
+ eval_funcall_prop m (External ef) vargs t m vres.
+Proof.
+ intros; red; intros.
+ simpl in TR. inversion TR; clear TR; subst tfn.
+ exploit event_match_inject; eauto. intros [A B].
+ exists f1; exists tm1; exists vres; intuition.
+ constructor; auto.
+Qed.
+
+Lemma transl_stmt_Sskip_correct:
+ forall (e : Csharpminor.env) (m : mem),
+ exec_stmt_prop e m Csharpminor.Sskip E0 m Csharpminor.Out_normal.
+Proof.
+ intros; red; intros. monadInv TR.
+ exists f1; exists te1; exists tm1; exists Out_normal.
+ intuition. subst ts; constructor. constructor.
+Qed.
+
+Lemma transl_stmt_Sexpr_correct:
+ forall (e : Csharpminor.env) (m : mem) (a : Csharpminor.expr)
+ (t: trace) (m1 : mem) (v : val),
+ Csharpminor.eval_expr prog nil e m a t m1 v ->
+ eval_expr_prop nil e m a t m1 v ->
+ exec_stmt_prop e m (Csharpminor.Sexpr a) t m1 Csharpminor.Out_normal.
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL1 [VINJ1 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ exists f2; exists te2; exists tm2; exists Out_normal.
+ intuition. subst ts. econstructor; eauto.
+ constructor.
+Qed.
+
+Lemma transl_stmt_Sassign_correct:
+ forall (e : Csharpminor.env) (m : mem)
+ (id : ident) (a : Csharpminor.expr) (t: trace) (m1 : mem) (b : block)
+ (chunk : memory_chunk) (v : val) (m2 : mem),
+ Csharpminor.eval_expr prog nil e m a t m1 v ->
+ eval_expr_prop nil e m a t m1 v ->
+ eval_var_ref prog e id b chunk ->
+ store chunk m1 b 0 v = Some m2 ->
+ exec_stmt_prop e m (Csharpminor.Sassign id a) t m2 Csharpminor.Out_normal.
+Proof.
+ intros; red; intros. monadInv TR; intro EQ0.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL1 [VINJ1 [MINJ1 [INCR12 MATCH1]]]]]]]].
+ exploit var_set_correct; eauto.
+ intros [te3 [tm3 [EVAL2 [MINJ2 MATCH2]]]].
+ exists f2; exists te3; exists tm3; exists Out_normal.
+ intuition. constructor.
+Qed.
+
+Lemma transl_stmt_Sstore_correct:
+ forall (e : Csharpminor.env) (m : mem)
+ (chunk : memory_chunk) (a b : Csharpminor.expr) (t1: trace) (m1 : mem)
+ (v1 : val) (t2: trace) (m2 : mem) (v2 : val)
+ (t3: trace) (m3 : mem),
+ Csharpminor.eval_expr prog nil e m a t1 m1 v1 ->
+ eval_expr_prop nil e m a t1 m1 v1 ->
+ Csharpminor.eval_expr prog nil e m1 b t2 m2 v2 ->
+ eval_expr_prop nil e m1 b t2 m2 v2 ->
+ storev chunk m2 v1 v2 = Some m3 ->
+ t3 = t1 ** t2 ->
+ exec_stmt_prop e m (Csharpminor.Sstore chunk a b) t3 m3 Csharpminor.Out_normal.
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL1 [VINJ1 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ exploit H2.
+ eauto.
+ eapply val_list_inject_incr; eauto.
+ eauto. eauto.
+ intros [f3 [te3 [tm3 [tv2 [EVAL2 [VINJ2 [MINJ3 [INCR3 MATCH3]]]]]]]].
+ exploit make_store_correct.
+ eexact EVAL1. eexact EVAL2. eauto. eauto.
+ eapply val_inject_incr; eauto. eauto.
+ intros [tm4 [EVAL [MINJ4 NEXTBLOCK]]].
+ exists f3; exists te3; exists tm4; exists Out_normal.
+ rewrite <- H6. subst t3. intuition.
+ constructor.
+ eapply inject_incr_trans; eauto.
+ assert (val_inject f3 v1 tv1). eapply val_inject_incr; eauto.
+ unfold storev in H3; destruct v1; try discriminate.
+ inversion H4.
+ rewrite NEXTBLOCK. replace (nextblock m3) with (nextblock m2).
+ eapply match_callstack_mapped; eauto. congruence.
+ exploit store_inv; eauto. simpl; symmetry; tauto.
+Qed.
+
+Lemma transl_stmt_Sseq_continue_correct:
+ forall (e : Csharpminor.env) (m : mem) (s1 s2 : Csharpminor.stmt)
+ (t1 t2: trace) (m1 m2 : mem) (t: trace) (out : Csharpminor.outcome),
+ Csharpminor.exec_stmt prog e m s1 t1 m1 Csharpminor.Out_normal ->
+ exec_stmt_prop e m s1 t1 m1 Csharpminor.Out_normal ->
+ Csharpminor.exec_stmt prog e m1 s2 t2 m2 out ->
+ exec_stmt_prop e m1 s2 t2 m2 out ->
+ t = t1 ** t2 ->
+ exec_stmt_prop e m (Csharpminor.Sseq s1 s2) t m2 out.
+Proof.
+ intros; red; intros; monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tout1 [EXEC1 [OINJ1 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ exploit H2; eauto.
+ intros [f3 [te3 [tm3 [tout2 [EXEC2 [OINJ2 [MINJ3 [INCR3 MATCH3]]]]]]]].
+ exists f3; exists te3; exists tm3; exists tout2.
+ intuition. subst ts; eapply exec_Sseq_continue; eauto.
+ inversion OINJ1. subst tout1. auto.
+ eapply inject_incr_trans; eauto.
+Qed.
+
+Lemma transl_stmt_Sseq_stop_correct:
+ forall (e : Csharpminor.env) (m : mem) (s1 s2 : Csharpminor.stmt)
+ (t1: trace) (m1 : mem) (out : Csharpminor.outcome),
+ Csharpminor.exec_stmt prog e m s1 t1 m1 out ->
+ exec_stmt_prop e m s1 t1 m1 out ->
+ out <> Csharpminor.Out_normal ->
+ exec_stmt_prop e m (Csharpminor.Sseq s1 s2) t1 m1 out.
+Proof.
+ intros; red; intros; monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tout1 [EXEC1 [OINJ1 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ exists f2; exists te2; exists tm2; exists tout1.
+ intuition. subst ts; eapply exec_Sseq_stop; eauto.
+ inversion OINJ1; subst out tout1; congruence.
+Qed.
+
+Lemma transl_stmt_Sifthenelse_true_correct:
+ forall (e : Csharpminor.env) (m : mem) (a : Csharpminor.expr)
+ (sl1 sl2 : Csharpminor.stmt)
+ (t1: trace) (m1 : mem) (v1 : val) (t2: trace) (m2 : mem)
+ (out : Csharpminor.outcome) (t: trace),
+ Csharpminor.eval_expr prog nil e m a t1 m1 v1 ->
+ eval_expr_prop nil e m a t1 m1 v1 ->
+ Val.is_true v1 ->
+ Csharpminor.exec_stmt prog e m1 sl1 t2 m2 out ->
+ exec_stmt_prop e m1 sl1 t2 m2 out ->
+ t = t1 ** t2 ->
+ exec_stmt_prop e m (Csharpminor.Sifthenelse a sl1 sl2) t m2 out.
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL1 [VINJ1 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ exploit H3; eauto.
+ intros [f3 [te3 [tm3 [tout [EVAL2 [OINJ [MINJ3 [INCR3 MATCH3]]]]]]]].
+ exists f3; exists te3; exists tm3; exists tout.
+ intuition.
+ subst ts t. eapply exec_ifthenelse_true; eauto.
+ inversion VINJ1; subst v1 tv1; simpl in H1; simpl; contradiction || auto.
+ eapply inject_incr_trans; eauto.
+Qed.
+
+Lemma transl_stmt_Sifthenelse_false_correct:
+ forall (e : Csharpminor.env) (m : mem) (a : Csharpminor.expr)
+ (sl1 sl2 : Csharpminor.stmt)
+ (t1: trace) (m1 : mem) (v1 : val) (t2: trace) (m2 : mem)
+ (out : Csharpminor.outcome) (t: trace),
+ Csharpminor.eval_expr prog nil e m a t1 m1 v1 ->
+ eval_expr_prop nil e m a t1 m1 v1 ->
+ Val.is_false v1 ->
+ Csharpminor.exec_stmt prog e m1 sl2 t2 m2 out ->
+ exec_stmt_prop e m1 sl2 t2 m2 out ->
+ t = t1 ** t2 ->
+ exec_stmt_prop e m (Csharpminor.Sifthenelse a sl1 sl2) t m2 out.
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL1 [VINJ1 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ exploit H3; eauto.
+ intros [f3 [te3 [tm3 [tout [EVAL2 [OINJ [MINJ3 [INCR3 MATCH3]]]]]]]].
+ exists f3; exists te3; exists tm3; exists tout.
+ intuition.
+ subst ts t. eapply exec_ifthenelse_false; eauto.
+ inversion VINJ1; subst v1 tv1; simpl in H1; simpl; contradiction || auto.
+ eapply inject_incr_trans; eauto.
+Qed.
+
+Lemma transl_stmt_Sloop_loop_correct:
+ forall (e : Csharpminor.env) (m : mem) (sl : Csharpminor.stmt)
+ (t1: trace) (m1: mem) (t2: trace) (m2 : mem)
+ (out : Csharpminor.outcome) (t: trace),
+ Csharpminor.exec_stmt prog e m sl t1 m1 Csharpminor.Out_normal ->
+ exec_stmt_prop e m sl t1 m1 Csharpminor.Out_normal ->
+ Csharpminor.exec_stmt prog e m1 (Csharpminor.Sloop sl) t2 m2 out ->
+ exec_stmt_prop e m1 (Csharpminor.Sloop sl) t2 m2 out ->
+ t = t1 ** t2 ->
+ exec_stmt_prop e m (Csharpminor.Sloop sl) t m2 out.
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tout1 [EVAL1 [OINJ1 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ exploit H2; eauto.
+ intros [f3 [te3 [tm3 [tout2 [EVAL2 [OINJ2 [MINJ3 [INCR3 MATCH3]]]]]]]].
+ exists f3; exists te3; exists tm3; exists tout2.
+ intuition.
+ subst ts. eapply exec_Sloop_loop; eauto.
+ inversion OINJ1; subst tout1; eauto.
+ eapply inject_incr_trans; eauto.
+Qed.
+
+Lemma transl_stmt_Sloop_exit_correct:
+ forall (e : Csharpminor.env) (m : mem) (sl : Csharpminor.stmt)
+ (t1: trace) (m1 : mem) (out : Csharpminor.outcome),
+ Csharpminor.exec_stmt prog e m sl t1 m1 out ->
+ exec_stmt_prop e m sl t1 m1 out ->
+ out <> Csharpminor.Out_normal ->
+ exec_stmt_prop e m (Csharpminor.Sloop sl) t1 m1 out.
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tout1 [EVAL1 [OINJ1 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ exists f2; exists te2; exists tm2; exists tout1.
+ intuition. subst ts; eapply exec_Sloop_stop; eauto.
+ inversion OINJ1; subst out tout1; congruence.
+Qed.
+
+Lemma transl_stmt_Sblock_correct:
+ forall (e : Csharpminor.env) (m : mem) (sl : Csharpminor.stmt)
+ (t1: trace) (m1 : mem) (out : Csharpminor.outcome),
+ Csharpminor.exec_stmt prog e m sl t1 m1 out ->
+ exec_stmt_prop e m sl t1 m1 out ->
+ exec_stmt_prop e m (Csharpminor.Sblock sl) t1 m1
+ (Csharpminor.outcome_block out).
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tout1 [EVAL1 [OINJ1 [MINJ2 [INCR2 MATCH2]]]]]]]].
+ exists f2; exists te2; exists tm2; exists (outcome_block tout1).
+ intuition. subst ts; eapply exec_Sblock; eauto.
+ inversion OINJ1; subst out tout1; simpl.
+ constructor.
+ destruct n; constructor.
+ constructor.
+ constructor; auto.
+Qed.
+
+Lemma transl_stmt_Sexit_correct:
+ forall (e : Csharpminor.env) (m : mem) (n : nat),
+ exec_stmt_prop e m (Csharpminor.Sexit n) E0 m (Csharpminor.Out_exit n).
+Proof.
+ intros; red; intros. monadInv TR.
+ exists f1; exists te1; exists tm1; exists (Out_exit n).
+ intuition. subst ts; constructor. constructor.
+Qed.
+
+Lemma transl_stmt_Sswitch_correct:
+ forall (e : Csharpminor.env) (m : mem)
+ (a : Csharpminor.expr) (cases : list (int * nat)) (default : nat)
+ (t1 : trace) (m1 : mem) (n : int),
+ Csharpminor.eval_expr prog nil e m a t1 m1 (Vint n) ->
+ eval_expr_prop nil e m a t1 m1 (Vint n) ->
+ exec_stmt_prop e m (Csharpminor.Sswitch a cases default) t1 m1
+ (Csharpminor.Out_exit (Csharpminor.switch_target n default cases)).
+Proof.
+ intros; red; intros. monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL [VINJ1 [MINJ2 [INCR MATCH2]]]]]]]].
+ exists f2; exists te2; exists tm2;
+ exists (Out_exit (switch_target n default cases)). intuition.
+ subst ts. constructor. inversion VINJ1. subst tv1. assumption.
+ constructor.
+Qed.
+
+Lemma transl_stmt_Sreturn_none_correct:
+ forall (e : Csharpminor.env) (m : mem),
+ exec_stmt_prop e m (Csharpminor.Sreturn None) E0 m
+ (Csharpminor.Out_return None).
+Proof.
+ intros; red; intros. monadInv TR.
+ exists f1; exists te1; exists tm1; exists (Out_return None).
+ intuition. subst ts; constructor. constructor.
+Qed.
+
+Lemma transl_stmt_Sreturn_some_correct:
+ forall (e : Csharpminor.env) (m : mem) (a : Csharpminor.expr)
+ (t1: trace) (m1 : mem) (v : val),
+ Csharpminor.eval_expr prog nil e m a t1 m1 v ->
+ eval_expr_prop nil e m a t1 m1 v ->
+ exec_stmt_prop e m (Csharpminor.Sreturn (Some a)) t1 m1
+ (Csharpminor.Out_return (Some v)).
+Proof.
+ intros; red; intros; monadInv TR.
+ exploit H0; eauto.
+ intros [f2 [te2 [tm2 [tv1 [EVAL [VINJ1 [MINJ2 [INCR MATCH2]]]]]]]].
+ exists f2; exists te2; exists tm2; exists (Out_return (Some tv1)).
+ intuition. subst ts; econstructor; eauto. constructor; auto.
+Qed.
+
+(** We conclude by an induction over the structure of the Csharpminor
+ evaluation derivation, using the lemmas above for each case. *)
+
+Lemma transl_function_correct:
+ forall m1 f vargs t m2 vres,
+ Csharpminor.eval_funcall prog m1 f vargs t m2 vres ->
+ eval_funcall_prop m1 f vargs t m2 vres.
+Proof
+ (eval_funcall_ind4 prog
+ eval_expr_prop
+ eval_exprlist_prop
+ eval_funcall_prop
+ exec_stmt_prop
+
+ transl_expr_Evar_correct
+ transl_expr_Eaddrof_correct
+ transl_expr_Eop_correct
+ transl_expr_Eload_correct
+ transl_expr_Ecall_correct
+ transl_expr_Econdition_true_correct
+ transl_expr_Econdition_false_correct
+ transl_expr_Elet_correct
+ transl_expr_Eletvar_correct
+ transl_expr_Ealloc_correct
+ transl_exprlist_Enil_correct
+ transl_exprlist_Econs_correct
+ transl_funcall_internal_correct
+ transl_funcall_external_correct
+ transl_stmt_Sskip_correct
+ transl_stmt_Sexpr_correct
+ transl_stmt_Sassign_correct
+ transl_stmt_Sstore_correct
+ transl_stmt_Sseq_continue_correct
+ transl_stmt_Sseq_stop_correct
+ transl_stmt_Sifthenelse_true_correct
+ transl_stmt_Sifthenelse_false_correct
+ transl_stmt_Sloop_loop_correct
+ transl_stmt_Sloop_exit_correct
+ transl_stmt_Sblock_correct
+ transl_stmt_Sexit_correct
+ transl_stmt_Sswitch_correct
+ transl_stmt_Sreturn_none_correct
+ transl_stmt_Sreturn_some_correct).
+
+(** The [match_globalenvs] relation holds for the global environments
+ of the source program and the transformed program. *)
+
+Lemma match_globalenvs_init:
+ let m := Genv.init_mem (program_of_program prog) in
+ let tm := Genv.init_mem tprog in
+ let f := fun b => if zlt b m.(nextblock) then Some(b, 0) else None in
+ match_globalenvs f.
+Proof.
+ intros. constructor.
+ (* globalvars *)
+ (* symbols *)
+ intros. split.
+ unfold f. rewrite zlt_true. auto. unfold m.
+ eapply Genv.find_symbol_inv; eauto.
+ rewrite <- H. apply symbols_preserved.
+ intros. unfold f. rewrite zlt_true. auto.
+ generalize (nextblock_pos m). omega.
+Qed.
+
+(** The correctness of the translation of a whole Csharpminor program
+ follows. *)
+
+Theorem transl_program_correct:
+ forall t n,
+ Csharpminor.exec_program prog t (Vint n) ->
+ exec_program tprog t (Vint n).
+Proof.
+ intros t n [b [fn [m [FINDS [FINDF [SIG EVAL]]]]]].
+ elim (function_ptr_translated _ _ FINDF). intros tfn [TFIND TR].
+ set (m0 := Genv.init_mem (program_of_program prog)) in *.
+ set (f := fun b => if zlt b m0.(nextblock) then Some(b, 0) else None).
+ assert (MINJ0: mem_inject f m0 m0).
+ unfold f; constructor; intros.
+ apply zlt_false; auto.
+ destruct (zlt b0 (nextblock m0)); try discriminate.
+ inversion H; subst b' delta.
+ split. auto.
+ constructor. compute. split; congruence. left; auto.
+ intros; omega.
+ generalize (Genv.initmem_block_init (program_of_program prog) b0). fold m0. intros [idata EQ].
+ rewrite EQ. simpl. apply Mem.contents_init_data_inject.
+ destruct (zlt b1 (nextblock m0)); try discriminate.
+ destruct (zlt b2 (nextblock m0)); try discriminate.
+ left; congruence.
+ assert (MATCH0: match_callstack f nil m0.(nextblock) m0.(nextblock) m0).
+ constructor. unfold f; apply match_globalenvs_init.
+ fold ge in EVAL.
+ exploit transl_function_correct; eauto.
+ intros [f1 [tm1 [tres [TEVAL [VINJ [MINJ1 [INCR MATCH1]]]]]]].
+ exists b; exists tfn; exists tm1.
+ split. fold tge. rewrite <- FINDS.
+ replace (prog_main prog) with (AST.prog_main tprog). fold ge. apply symbols_preserved.
+ transitivity (AST.prog_main (program_of_program prog)).
+ apply transform_partial_program_main with (transl_fundef gce). assumption.
+ reflexivity.
+ split. assumption.
+ split. rewrite <- SIG. apply sig_preserved; auto.
+ rewrite (Genv.init_mem_transf_partial (transl_fundef gce) _ TRANSL).
+ inversion VINJ; subst tres. assumption.
+Qed.
+
+End TRANSLATION.