From b4a08d0815342b6238d307864f0823d0f07bb691 Mon Sep 17 00:00:00 2001 From: David Monniaux Date: Tue, 26 May 2020 22:04:20 +0200 Subject: k1c -> kvx changes --- kvx/Asmblockgenproof.v | 1807 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1807 insertions(+) create mode 100644 kvx/Asmblockgenproof.v (limited to 'kvx/Asmblockgenproof.v') diff --git a/kvx/Asmblockgenproof.v b/kvx/Asmblockgenproof.v new file mode 100644 index 00000000..5cb498bc --- /dev/null +++ b/kvx/Asmblockgenproof.v @@ -0,0 +1,1807 @@ +(* *************************************************************) +(* *) +(* The Compcert verified compiler *) +(* *) +(* Sylvain Boulmé Grenoble-INP, VERIMAG *) +(* Xavier Leroy INRIA Paris-Rocquencourt *) +(* David Monniaux CNRS, VERIMAG *) +(* Cyril Six Kalray *) +(* *) +(* Copyright Kalray. Copyright VERIMAG. All rights reserved. *) +(* This file is distributed under the terms of the INRIA *) +(* Non-Commercial License Agreement. *) +(* *) +(* *************************************************************) + +(** Correctness proof for RISC-V generation: main proof. *) + +Require Import Coqlib Errors. +Require Import Integers Floats AST Linking. +Require Import Values Memory Events Globalenvs Smallstep. +Require Import Op Locations Machblock Conventions Asmblock. +Require Import Asmblockgen Asmblockgenproof0 Asmblockgenproof1 Asmblockprops. +Require Import Axioms. + +Module MB := Machblock. +Module AB := Asmvliw. + +Definition match_prog (p: Machblock.program) (tp: Asmvliw.program) := + match_program (fun _ f tf => transf_fundef f = OK tf) eq p tp. + +Lemma transf_program_match: + forall p tp, transf_program p = OK tp -> match_prog p tp. +Proof. + intros. eapply match_transform_partial_program; eauto. +Qed. + +Section PRESERVATION. + +Variable prog: Machblock.program. +Variable tprog: Asmvliw.program. +Hypothesis TRANSF: match_prog prog tprog. +Let ge := Genv.globalenv prog. +Let tge := Genv.globalenv tprog. + +Lemma symbols_preserved: + forall (s: ident), Genv.find_symbol tge s = Genv.find_symbol ge s. +Proof (Genv.find_symbol_match TRANSF). + +Lemma senv_preserved: + Senv.equiv ge tge. +Proof (Genv.senv_match TRANSF). + +Lemma functions_translated: + forall b f, + Genv.find_funct_ptr ge b = Some f -> + exists tf, + Genv.find_funct_ptr tge b = Some tf /\ transf_fundef f = OK tf. +Proof (Genv.find_funct_ptr_transf_partial TRANSF). + +Lemma functions_transl: + forall fb f tf, + Genv.find_funct_ptr ge fb = Some (Internal f) -> + transf_function f = OK tf -> + Genv.find_funct_ptr tge fb = Some (Internal tf). +Proof. + intros. exploit functions_translated; eauto. intros [tf' [A B]]. + monadInv B. rewrite H0 in EQ; inv EQ; auto. +Qed. + +Lemma transf_function_no_overflow: + forall f tf, + transf_function f = OK tf -> size_blocks tf.(fn_blocks) <= Ptrofs.max_unsigned. +Proof. + intros. monadInv H. destruct (zlt Ptrofs.max_unsigned (size_blocks x.(fn_blocks))); inv EQ0. + omega. +Qed. + +Section TRANSL_LABEL. (* Lemmas on translation of MB.is_label into AB.is_label *) + +Lemma gen_bblocks_label: + forall hd bdy ex tbb tc, + gen_bblocks hd bdy ex = tbb::tc -> + header tbb = hd. +Proof. + intros until tc. intros GENB. unfold gen_bblocks in GENB. + destruct (extract_ctl ex); try destruct c; try destruct i; try destruct bdy. + all: inv GENB; simpl; auto. +Qed. + +Lemma gen_bblocks_label2: + forall hd bdy ex tbb1 tbb2, + gen_bblocks hd bdy ex = tbb1::tbb2::nil -> + header tbb2 = nil. +Proof. + intros until tbb2. intros GENB. unfold gen_bblocks in GENB. + destruct (extract_ctl ex); try destruct c; try destruct i; try destruct bdy. + all: inv GENB; simpl; auto. +Qed. + +Remark in_dec_transl: + forall lbl hd, + (if in_dec lbl hd then true else false) = (if MB.in_dec lbl hd then true else false). +Proof. + intros. destruct (in_dec lbl hd), (MB.in_dec lbl hd). all: tauto. +Qed. + +Lemma transl_is_label: + forall lbl bb tbb f ep tc, + transl_block f bb ep = OK (tbb::tc) -> + is_label lbl tbb = MB.is_label lbl bb. +Proof. + intros until tc. intros TLB. + destruct tbb as [thd tbdy tex]; simpl in *. + monadInv TLB. + unfold is_label. simpl. + apply gen_bblocks_label in H0. simpl in H0. subst. + rewrite in_dec_transl. auto. +Qed. + +Lemma transl_is_label_false2: + forall lbl bb f ep tbb1 tbb2, + transl_block f bb ep = OK (tbb1::tbb2::nil) -> + is_label lbl tbb2 = false. +Proof. + intros until tbb2. intros TLB. + destruct tbb2 as [thd tbdy tex]; simpl in *. + monadInv TLB. apply gen_bblocks_label2 in H0. simpl in H0. subst. + apply is_label_correct_false. simpl. auto. +Qed. + +Lemma transl_is_label2: + forall f bb ep tbb1 tbb2 lbl, + transl_block f bb ep = OK (tbb1::tbb2::nil) -> + is_label lbl tbb1 = MB.is_label lbl bb + /\ is_label lbl tbb2 = false. +Proof. + intros. split. eapply transl_is_label; eauto. eapply transl_is_label_false2; eauto. +Qed. + +Lemma transl_block_nonil: + forall f c ep tc, + transl_block f c ep = OK tc -> + tc <> nil. +Proof. + intros. monadInv H. unfold gen_bblocks. + destruct (extract_ctl x0); try destruct c0; try destruct x; try destruct i. + all: discriminate. +Qed. + +Lemma transl_block_limit: forall f bb ep tbb1 tbb2 tbb3 tc, + ~transl_block f bb ep = OK (tbb1 :: tbb2 :: tbb3 :: tc). +Proof. + intros. intro. monadInv H. + unfold gen_bblocks in H0. + destruct (extract_ctl x0); try destruct x; try destruct c; try destruct i. + all: discriminate. +Qed. + +Lemma find_label_transl_false: + forall x f lbl bb ep x', + transl_block f bb ep = OK x -> + MB.is_label lbl bb = false -> + find_label lbl (x++x') = find_label lbl x'. +Proof. + intros until x'. intros TLB MBis; simpl; auto. + destruct x as [|x0 x1]; simpl; auto. + destruct x1 as [|x1 x2]; simpl; auto. + - erewrite <- transl_is_label in MBis; eauto. rewrite MBis. auto. + - destruct x2 as [|x2 x3]; simpl; auto. + + erewrite <- transl_is_label in MBis; eauto. rewrite MBis. + erewrite transl_is_label_false2; eauto. + + apply transl_block_limit in TLB. destruct TLB. +Qed. + +Lemma transl_blocks_label: + forall lbl f c tc ep, + transl_blocks f c ep = OK tc -> + match MB.find_label lbl c with + | None => find_label lbl tc = None + | Some c' => exists tc', find_label lbl tc = Some tc' /\ transl_blocks f c' false = OK tc' + end. +Proof. + induction c; simpl; intros. + inv H. auto. + monadInv H. + destruct (MB.is_label lbl a) eqn:MBis. + - destruct x as [|tbb tc]. { apply transl_block_nonil in EQ. contradiction. } + simpl find_label. exploit transl_is_label; eauto. intros ABis. rewrite MBis in ABis. + rewrite ABis. + eexists. eexists. split; eauto. simpl transl_blocks. + assert (MB.header a <> nil). + { apply MB.is_label_correct_true in MBis. + destruct (MB.header a). contradiction. discriminate. } + destruct (MB.header a); try contradiction. + rewrite EQ. simpl. rewrite EQ1. simpl. auto. + - apply IHc in EQ1. destruct (MB.find_label lbl c). + + destruct EQ1 as (tc' & FIND & TLBS). exists tc'; eexists; auto. + erewrite find_label_transl_false; eauto. + + erewrite find_label_transl_false; eauto. +Qed. + +Lemma find_label_nil: + forall bb lbl c, + header bb = nil -> + find_label lbl (bb::c) = find_label lbl c. +Proof. + intros. destruct bb as [hd bdy ex]; simpl in *. subst. + assert (is_label lbl {| AB.header := nil; AB.body := bdy; AB.exit := ex; AB.correct := correct |} = false). + { erewrite <- is_label_correct_false. simpl. auto. } + rewrite H. auto. +Qed. + +Theorem transl_find_label: + forall lbl f tf, + transf_function f = OK tf -> + match MB.find_label lbl f.(MB.fn_code) with + | None => find_label lbl tf.(fn_blocks) = None + | Some c => exists tc, find_label lbl tf.(fn_blocks) = Some tc /\ transl_blocks f c false = OK tc + end. +Proof. + intros. monadInv H. destruct (zlt Ptrofs.max_unsigned (size_blocks (fn_blocks x))); inv EQ0. clear g. + monadInv EQ. unfold make_prologue. simpl fn_blocks. repeat (rewrite find_label_nil); simpl; auto. + eapply transl_blocks_label; eauto. +Qed. + +End TRANSL_LABEL. + +(** A valid branch in a piece of Machblock code translates to a valid ``go to'' + transition in the generated Asmblock code. *) + +Lemma find_label_goto_label: + forall f tf lbl rs m c' b ofs, + Genv.find_funct_ptr ge b = Some (Internal f) -> + transf_function f = OK tf -> + rs PC = Vptr b ofs -> + MB.find_label lbl f.(MB.fn_code) = Some c' -> + exists tc', exists rs', + goto_label tf lbl rs m = Next rs' m + /\ transl_code_at_pc ge (rs' PC) b f c' false tf tc' + /\ forall r, r <> PC -> rs'#r = rs#r. +Proof. + intros. exploit (transl_find_label lbl f tf); eauto. rewrite H2. + intros (tc & A & B). + exploit label_pos_code_tail; eauto. instantiate (1 := 0). + intros [pos' [P [Q R]]]. + exists tc; exists (rs#PC <- (Vptr b (Ptrofs.repr pos'))). + split. unfold goto_label. unfold par_goto_label. rewrite P. rewrite H1. auto. + split. rewrite Pregmap.gss. constructor; auto. + rewrite Ptrofs.unsigned_repr. replace (pos' - 0) with pos' in Q. + auto. omega. + generalize (transf_function_no_overflow _ _ H0). omega. + intros. apply Pregmap.gso; auto. +Qed. + +(** Existence of return addresses *) + +Lemma return_address_exists: + forall b f c, is_tail (b :: c) f.(MB.fn_code) -> + exists ra, return_address_offset f c ra. +Proof. + intros. eapply Asmblockgenproof0.return_address_exists; eauto. + +- intros. monadInv H0. + destruct (zlt Ptrofs.max_unsigned (size_blocks x.(fn_blocks))); inv EQ0. monadInv EQ. simpl. + exists x; exists true; split; auto. + repeat constructor. +- exact transf_function_no_overflow. +Qed. + +(** * Proof of semantic preservation *) + +(** Semantic preservation is proved using a complex simulation diagram + of the following form. +<< + MB.step + ----------------------------------------> + header body exit + st1 -----> st2 -----> st3 ------------------> st4 + | | | | + | (A) | (B) | (C) | + match_codestate | | | | + | header | body1 | body2 | match_states + cs1 -----> cs2 -----> cs3 ------> cs4 | + | / \ exit | + match_asmstate | --------------- --->--- | + | / match_asmstate \ | + st'1 ---------------------------------------> st'2 + AB.step * +>> + The invariant between each MB.step/AB.step is the [match_states] predicate below. + However, we also need to introduce an intermediary state [Codestate] which allows + us to reason on a finer grain, executing header, body and exit separately. + + This [Codestate] consists in a state like [Asmblock.State], except that the + code is directly stored in the state, much like [Machblock.State]. It also features + additional useful elements to keep track of while executing a bblock. +*) + +Remark preg_of_not_FP: forall r, negb (mreg_eq r MFP) = true -> IR FP <> preg_of r. +Proof. + intros. change (IR FP) with (preg_of MFP). red; intros. + exploit preg_of_injective; eauto. intros; subst r; discriminate. +Qed. + +Inductive match_states: Machblock.state -> Asmvliw.state -> Prop := + | match_states_intro: + forall s fb sp c ep ms m m' rs f tf tc + (STACKS: match_stack ge s) + (FIND: Genv.find_funct_ptr ge fb = Some (Internal f)) + (MEXT: Mem.extends m m') + (AT: transl_code_at_pc ge (rs PC) fb f c ep tf tc) + (AG: agree ms sp rs) + (DXP: ep = true -> rs#FP = parent_sp s), + match_states (Machblock.State s fb sp c ms m) + (Asmvliw.State rs m') + | match_states_call: + forall s fb ms m m' rs + (STACKS: match_stack ge s) + (MEXT: Mem.extends m m') + (AG: agree ms (parent_sp s) rs) + (ATPC: rs PC = Vptr fb Ptrofs.zero) + (ATLR: rs RA = parent_ra s), + match_states (Machblock.Callstate s fb ms m) + (Asmvliw.State rs m') + | match_states_return: + forall s ms m m' rs + (STACKS: match_stack ge s) + (MEXT: Mem.extends m m') + (AG: agree ms (parent_sp s) rs) + (ATPC: rs PC = parent_ra s), + match_states (Machblock.Returnstate s ms m) + (Asmvliw.State rs m'). + +Record codestate := + Codestate { pstate: state; (**r projection to Asmblock.state *) + pheader: list label; + pbody1: list basic; (**r list of basic instructions coming from the translation of the Machblock body *) + pbody2: list basic; (**r list of basic instructions coming from the translation of the Machblock exit *) + pctl: option control; (**r exit instruction, coming from the translation of the Machblock exit *) + ep: bool; (**r reflects the [ep] variable used in the translation *) + rem: list AB.bblock; (**r remaining bblocks to execute *) + cur: bblock (**r current bblock to execute - to keep track of its size when incrementing PC *) + }. + +(* The part that deals with Machblock <-> Codestate agreement + * Note about DXP: the property of [ep] only matters if the current block doesn't have a header, hence the condition *) +Inductive match_codestate fb: Machblock.state -> codestate -> Prop := + | match_codestate_intro: + forall s sp ms m rs0 m0 f tc ep c bb tbb tbc tbi + (STACKS: match_stack ge s) + (FIND: Genv.find_funct_ptr ge fb = Some (Internal f)) + (MEXT: Mem.extends m m0) + (TBC: transl_basic_code f (MB.body bb) (if MB.header bb then ep else false) = OK tbc) + (TIC: transl_instr_control f (MB.exit bb) = OK tbi) + (TBLS: transl_blocks f c false = OK tc) + (AG: agree ms sp rs0) + (DXP: (if MB.header bb then ep else false) = true -> rs0#FP = parent_sp s) + , + match_codestate fb (Machblock.State s fb sp (bb::c) ms m) + {| pstate := (Asmvliw.State rs0 m0); + pheader := (MB.header bb); + pbody1 := tbc; + pbody2 := extract_basic tbi; + pctl := extract_ctl tbi; + ep := ep; + rem := tc; + cur := tbb + |} +. + +(* The part ensuring that the code in Codestate actually resides at [rs PC] *) +Inductive match_asmstate fb: codestate -> Asmvliw.state -> Prop := + | match_asmstate_some: + forall rs f tf tc m tbb ofs ep tbdy tex lhd + (FIND: Genv.find_funct_ptr ge fb = Some (Internal f)) + (TRANSF: transf_function f = OK tf) + (PCeq: rs PC = Vptr fb ofs) + (TAIL: code_tail (Ptrofs.unsigned ofs) (fn_blocks tf) (tbb::tc)) + , + match_asmstate fb + {| pstate := (Asmvliw.State rs m); + pheader := lhd; + pbody1 := tbdy; + pbody2 := extract_basic tex; + pctl := extract_ctl tex; + ep := ep; + rem := tc; + cur := tbb |} + (Asmvliw.State rs m) +. + +(* Useful for dealing with the many cases in some proofs *) +Ltac exploreInst := + repeat match goal with + | [ H : match ?var with | _ => _ end = _ |- _ ] => destruct var + | [ H : OK _ = OK _ |- _ ] => monadInv H + | [ |- context[if ?b then _ else _] ] => destruct b + | [ |- context[match ?m with | _ => _ end] ] => destruct m + | [ |- context[match ?m as _ return _ with | _ => _ end]] => destruct m + | [ H : bind _ _ = OK _ |- _ ] => monadInv H + | [ H : Error _ = OK _ |- _ ] => inversion H + end. + +(** Some translation properties *) + +Lemma transl_blocks_nonil: + forall f bb c tc ep, + transl_blocks f (bb::c) ep = OK tc -> + exists tbb tc', tc = tbb :: tc'. +Proof. + intros until ep0. intros TLBS. monadInv TLBS. monadInv EQ. unfold gen_bblocks. + destruct (extract_ctl x2). + - destruct c0; destruct i; simpl; eauto. destruct x1; simpl; eauto. + - destruct x1; simpl; eauto. +Qed. + +Lemma no_builtin_preserved: + forall f ex x2, + (forall ef args res, ex <> Some (MBbuiltin ef args res)) -> + transl_instr_control f ex = OK x2 -> + (exists i, extract_ctl x2 = Some (PCtlFlow i)) + \/ extract_ctl x2 = None. +Proof. + intros until x2. intros Hbuiltin TIC. + destruct ex. + - destruct c. + (* MBcall *) + + simpl in TIC. exploreInst; simpl; eauto. + (* MBtailcall *) + + simpl in TIC. exploreInst; simpl; eauto. + (* MBbuiltin *) + + assert (H: Some (MBbuiltin e l b) <> Some (MBbuiltin e l b)). + apply Hbuiltin. contradict H; auto. + (* MBgoto *) + + simpl in TIC. exploreInst; simpl; eauto. + (* MBcond *) + + simpl in TIC. unfold transl_cbranch in TIC. exploreInst; simpl; eauto. + * unfold transl_opt_compuimm. exploreInst; simpl; eauto. + * unfold transl_opt_compluimm. exploreInst; simpl; eauto. + * unfold transl_comp_float64. exploreInst; simpl; eauto. + * unfold transl_comp_notfloat64. exploreInst; simpl; eauto. + * unfold transl_comp_float32. exploreInst; simpl; eauto. + * unfold transl_comp_notfloat32. exploreInst; simpl; eauto. + (* MBjumptable *) + + simpl in TIC. exploreInst; simpl; eauto. + (* MBreturn *) + + simpl in TIC. monadInv TIC. simpl. eauto. + - monadInv TIC. simpl; auto. +Qed. + +Lemma transl_blocks_distrib: + forall c f bb tbb tc ep, + transl_blocks f (bb::c) ep = OK (tbb::tc) + -> (forall ef args res, MB.exit bb <> Some (MBbuiltin ef args res)) + -> transl_block f bb (if MB.header bb then ep else false) = OK (tbb :: nil) + /\ transl_blocks f c false = OK tc. +Proof. + intros until ep0. intros TLBS Hbuiltin. + destruct bb as [hd bdy ex]. + monadInv TLBS. monadInv EQ. + exploit no_builtin_preserved; eauto. intros Hectl. destruct Hectl. + - destruct H as [i Hectl]. + unfold gen_bblocks in H0. rewrite Hectl in H0. inv H0. + simpl in *. unfold transl_block; simpl. rewrite EQ0. rewrite EQ. simpl. + unfold gen_bblocks. rewrite Hectl. auto. + - unfold gen_bblocks in H0. rewrite H in H0. + destruct x1 as [|bi x1]. + + simpl in H0. inv H0. simpl in *. unfold transl_block; simpl. rewrite EQ0. rewrite EQ. simpl. + unfold gen_bblocks. rewrite H. auto. + + simpl in H0. inv H0. simpl in *. unfold transl_block; simpl. rewrite EQ0. rewrite EQ. simpl. + unfold gen_bblocks. rewrite H. auto. +Qed. + +Lemma gen_bblocks_nobuiltin: + forall thd tbdy tex tbb, + (tbdy <> nil \/ extract_ctl tex <> None) -> + (forall ef args res, extract_ctl tex <> Some (PExpand (Pbuiltin ef args res))) -> + gen_bblocks thd tbdy tex = tbb :: nil -> + header tbb = thd + /\ body tbb = tbdy ++ extract_basic tex + /\ exit tbb = extract_ctl tex. +Proof. + intros until tbb. intros Hnonil Hnobuiltin GENB. unfold gen_bblocks in GENB. + destruct (extract_ctl tex) eqn:ECTL. + - destruct c. + + destruct i; try (inv GENB; simpl; auto; fail). + assert False. eapply Hnobuiltin. eauto. destruct H. + + inv GENB. simpl. auto. + - inversion Hnonil. + + destruct tbdy as [|bi tbdy]; try (contradict H; simpl; auto; fail). inv GENB. auto. + + contradict H; simpl; auto. +Qed. + +Lemma transl_instr_basic_nonil: + forall k f bi ep x, + transl_instr_basic f bi ep k = OK x -> + x <> nil. +Proof. + intros until x. intros TIB. + destruct bi. + - simpl in TIB. unfold loadind in TIB. exploreInst; try discriminate. + - simpl in TIB. unfold storeind in TIB. exploreInst; try discriminate. + - simpl in TIB. monadInv TIB. unfold loadind in EQ. exploreInst; try discriminate. + - simpl in TIB. unfold transl_op in TIB. exploreInst; try discriminate. + unfold transl_cond_op in EQ0. exploreInst; try discriminate. + unfold transl_cond_float64. exploreInst; try discriminate. + unfold transl_cond_notfloat64. exploreInst; try discriminate. + unfold transl_cond_float32. exploreInst; try discriminate. + unfold transl_cond_notfloat32. exploreInst; try discriminate. + - simpl in TIB. unfold transl_load in TIB. exploreInst; try discriminate. + all: monadInv TIB; unfold transl_memory_access in EQ0; unfold transl_memory_access2 in EQ0; unfold transl_memory_access2XS in EQ0; exploreInst; try discriminate. + - simpl in TIB. unfold transl_store in TIB. exploreInst; try discriminate. + all: monadInv TIB; unfold transl_memory_access in EQ0; unfold transl_memory_access2 in EQ0; unfold transl_memory_access2XS in EQ0; exploreInst; try discriminate. +Qed. + +Lemma transl_basic_code_nonil: + forall bdy f x ep, + bdy <> nil -> + transl_basic_code f bdy ep = OK x -> + x <> nil. +Proof. + induction bdy as [|bi bdy]. + intros. contradict H0; auto. + destruct bdy as [|bi2 bdy]. + - clear IHbdy. intros f x b _ TBC. simpl in TBC. eapply transl_instr_basic_nonil; eauto. + - intros f x b Hnonil TBC. remember (bi2 :: bdy) as bdy'. + monadInv TBC. + assert (x0 <> nil). + eapply IHbdy; eauto. subst bdy'. discriminate. + eapply transl_instr_basic_nonil; eauto. +Qed. + +Lemma transl_instr_control_nonil: + forall ex f x, + ex <> None -> + transl_instr_control f ex = OK x -> + extract_ctl x <> None. +Proof. + intros ex f x Hnonil TIC. + destruct ex as [ex|]. + - clear Hnonil. destruct ex. + all: try (simpl in TIC; exploreInst; discriminate). + + simpl in TIC. unfold transl_cbranch in TIC. exploreInst; try discriminate. + * unfold transl_opt_compuimm. exploreInst; try discriminate. + * unfold transl_opt_compluimm. exploreInst; try discriminate. + * unfold transl_comp_float64. exploreInst; try discriminate. + * unfold transl_comp_notfloat64. exploreInst; try discriminate. + * unfold transl_comp_float32. exploreInst; try discriminate. + * unfold transl_comp_notfloat32. exploreInst; try discriminate. + - contradict Hnonil; auto. +Qed. + +Lemma transl_instr_control_nobuiltin: + forall f ex x, + (forall ef args res, ex <> Some (MBbuiltin ef args res)) -> + transl_instr_control f ex = OK x -> + (forall ef args res, extract_ctl x <> Some (PExpand (Pbuiltin ef args res))). +Proof. + intros until x. intros Hnobuiltin TIC. intros until res. + unfold transl_instr_control in TIC. exploreInst. + all: try discriminate. + - assert False. eapply Hnobuiltin; eauto. destruct H. + - unfold transl_cbranch in TIC. exploreInst. + all: try discriminate. + * unfold transl_opt_compuimm. exploreInst. all: try discriminate. + * unfold transl_opt_compluimm. exploreInst. all: try discriminate. + * unfold transl_comp_float64. exploreInst; try discriminate. + * unfold transl_comp_notfloat64. exploreInst; try discriminate. + * unfold transl_comp_float32. exploreInst; try discriminate. + * unfold transl_comp_notfloat32. exploreInst; try discriminate. +Qed. + +(* Proving that one can decompose a [match_state] relation into a [match_codestate] + and a [match_asmstate], along with some helpful properties tying both relations together *) + +Theorem match_state_codestate: + forall mbs abs s fb sp bb c ms m, + (forall ef args res, MB.exit bb <> Some (MBbuiltin ef args res)) -> + (MB.body bb <> nil \/ MB.exit bb <> None) -> + mbs = (Machblock.State s fb sp (bb::c) ms m) -> + match_states mbs abs -> + exists cs fb f tbb tc ep, + match_codestate fb mbs cs /\ match_asmstate fb cs abs + /\ Genv.find_funct_ptr ge fb = Some (Internal f) + /\ transl_blocks f (bb::c) ep = OK (tbb::tc) + /\ body tbb = pbody1 cs ++ pbody2 cs + /\ exit tbb = pctl cs + /\ cur cs = tbb /\ rem cs = tc + /\ pstate cs = abs. +Proof. + intros until m. intros Hnobuiltin Hnotempty Hmbs MS. subst. inv MS. + inv AT. clear H0. exploit transl_blocks_nonil; eauto. intros (tbb & tc' & Htc). subst. + exploit transl_blocks_distrib; eauto. intros (TLB & TLBS). clear H2. + monadInv TLB. exploit gen_bblocks_nobuiltin; eauto. + { inversion Hnotempty. + - destruct (MB.body bb) as [|bi bdy]; try (contradict H0; simpl; auto; fail). + left. eapply transl_basic_code_nonil; eauto. + - destruct (MB.exit bb) as [ei|]; try (contradict H0; simpl; auto; fail). + right. eapply transl_instr_control_nonil; eauto. } + eapply transl_instr_control_nobuiltin; eauto. + intros (Hth & Htbdy & Htexit). + exists {| pstate := (State rs m'); pheader := (Machblock.header bb); pbody1 := x; pbody2 := extract_basic x0; + pctl := extract_ctl x0; ep := ep0; rem := tc'; cur := tbb |}, fb, f, tbb, tc', ep0. + repeat split. 1-2: econstructor; eauto. + { destruct (MB.header bb). eauto. discriminate. } eauto. + unfold transl_blocks. fold transl_blocks. unfold transl_block. rewrite EQ. simpl. rewrite EQ1; simpl. + rewrite TLBS. simpl. rewrite H2. + all: simpl; auto. +Qed. + +Definition mb_remove_body (bb: MB.bblock) := + {| MB.header := MB.header bb; MB.body := nil; MB.exit := MB.exit bb |}. + +Lemma exec_straight_pnil: + forall c rs1 m1 rs2 m2, + exec_straight tge c rs1 m1 (Pnop ::g nil) rs2 m2 -> + exec_straight tge c rs1 m1 nil rs2 m2. +Proof. + intros. eapply exec_straight_trans. eapply H. econstructor; eauto. +Qed. + +Lemma transl_block_nobuiltin: + forall f bb ep tbb, + (MB.body bb <> nil \/ MB.exit bb <> None) -> + (forall ef args res, MB.exit bb <> Some (MBbuiltin ef args res)) -> + transl_block f bb ep = OK (tbb :: nil) -> + exists c c', + transl_basic_code f (MB.body bb) ep = OK c + /\ transl_instr_control f (MB.exit bb) = OK c' + /\ body tbb = c ++ extract_basic c' + /\ exit tbb = extract_ctl c'. +Proof. + intros until tbb. intros Hnonil Hnobuiltin TLB. monadInv TLB. destruct Hnonil. + - eexists. eexists. split; eauto. split; eauto. eapply gen_bblocks_nobuiltin; eauto. + left. eapply transl_basic_code_nonil; eauto. eapply transl_instr_control_nobuiltin; eauto. + - eexists. eexists. split; eauto. split; eauto. eapply gen_bblocks_nobuiltin; eauto. + right. eapply transl_instr_control_nonil; eauto. eapply transl_instr_control_nobuiltin; eauto. +Qed. + +Lemma nextblock_preserves: + forall rs rs' bb r, + rs' = nextblock bb rs -> + data_preg r = true -> + rs r = rs' r. +Proof. + intros. destruct r; try discriminate. + subst. Simpl. +Qed. + +Remark cons3_app {A: Type}: + forall a b c (l: list A), + a :: b :: c :: l = (a :: b :: c :: nil) ++ l. +Proof. + intros. simpl. auto. +Qed. + +Lemma exec_straight_opt_body2: + forall c rs1 m1 c' rs2 m2, + exec_straight_opt tge c rs1 m1 c' rs2 m2 -> + exists body, + exec_body tge body rs1 m1 = Next rs2 m2 + /\ (basics_to_code body) ++g c' = c. +Proof. + intros until m2. intros EXES. + inv EXES. + - exists nil. split; auto. + - eapply exec_straight_body2. auto. +Qed. + +Lemma extract_basics_to_code: + forall lb c, + extract_basic (basics_to_code lb ++ c) = lb ++ extract_basic c. +Proof. + induction lb; intros; simpl; congruence. +Qed. + +Lemma extract_ctl_basics_to_code: + forall lb c, + extract_ctl (basics_to_code lb ++ c) = extract_ctl c. +Proof. + induction lb; intros; simpl; congruence. +Qed. + +(* See (C) in the diagram. The proofs are mostly adapted from the previous Mach->Asm proofs, but are + unfortunately quite cumbersome. To reproduce them, it's best to have a Coq IDE with you and see by + yourself the steps *) +Theorem step_simu_control: + forall bb' fb fn s sp c ms' m' rs2 m2 t S'' rs1 m1 tbb tbdy2 tex cs2, + MB.body bb' = nil -> + (forall ef args res, MB.exit bb' <> Some (MBbuiltin ef args res)) -> + Genv.find_funct_ptr tge fb = Some (Internal fn) -> + pstate cs2 = (Asmvliw.State rs2 m2) -> + pbody1 cs2 = nil -> pbody2 cs2 = tbdy2 -> pctl cs2 = tex -> + cur cs2 = tbb -> + match_codestate fb (MB.State s fb sp (bb'::c) ms' m') cs2 -> + match_asmstate fb cs2 (Asmvliw.State rs1 m1) -> + exit_step return_address_offset ge (MB.exit bb') (MB.State s fb sp (bb'::c) ms' m') t S'' -> + (exists rs3 m3 rs4 m4, + exec_body tge tbdy2 rs2 m2 = Next rs3 m3 + /\ exec_control_rel tge fn tex tbb rs3 m3 rs4 m4 + /\ match_states S'' (State rs4 m4)). +Proof. + intros until cs2. intros Hbody Hbuiltin FIND Hpstate Hpbody1 Hpbody2 Hpctl Hcur MCS MAS ESTEP. + inv ESTEP. + - inv MCS. inv MAS. simpl in *. + inv Hpstate. + destruct ctl. + + (* MBcall *) + destruct bb' as [mhd' mbdy' mex']; simpl in *. subst. + inv TBC. inv TIC. inv H0. + + assert (f0 = f) by congruence. subst f0. + assert (NOOV: size_blocks tf.(fn_blocks) <= Ptrofs.max_unsigned). + eapply transf_function_no_overflow; eauto. + destruct s1 as [rf|fid]; simpl in H7. + * (* Indirect call *) + monadInv H1. + assert (ms' rf = Vptr f' Ptrofs.zero). + { unfold find_function_ptr in H14. destruct (ms' rf); try discriminate. + revert H14; predSpec Ptrofs.eq Ptrofs.eq_spec i Ptrofs.zero; intros; congruence. } + assert (rs2 x = Vptr f' Ptrofs.zero). + { exploit ireg_val; eauto. rewrite H; intros LD; inv LD; auto. } + generalize (code_tail_next_int _ _ _ _ NOOV TAIL). intro CT1. + remember (Ptrofs.add _ _) as ofs'. + assert (TCA: transl_code_at_pc ge (Vptr fb ofs') fb f c false tf tc). + { econstructor; eauto. } + assert (f1 = f) by congruence. subst f1. + exploit return_address_offset_correct; eauto. intros; subst ra. + + repeat eexists. + rewrite H6. econstructor; eauto. + rewrite H7. econstructor; eauto. + econstructor; eauto. + econstructor; eauto. eapply agree_sp_def; eauto. simpl. eapply agree_exten; eauto. intros. Simpl. + simpl. Simpl. rewrite PCeq. rewrite Heqofs'. simpl. auto. + + * (* Direct call *) + monadInv H1. + generalize (code_tail_next_int _ _ _ _ NOOV TAIL). intro CT1. + remember (Ptrofs.add _ _) as ofs'. + assert (TCA: transl_code_at_pc ge (Vptr fb ofs') fb f c false tf tc). + econstructor; eauto. + assert (f1 = f) by congruence. subst f1. + exploit return_address_offset_correct; eauto. intros; subst ra. + repeat eexists. + rewrite H6. econstructor; eauto. + rewrite H7. econstructor; eauto. + econstructor; eauto. + econstructor; eauto. eapply agree_sp_def; eauto. simpl. eapply agree_exten; eauto. intros. Simpl. + Simpl. unfold Genv.symbol_address. rewrite symbols_preserved. simpl in H14. rewrite H14. auto. + Simpl. simpl. subst. Simpl. simpl. unfold Val.offset_ptr. rewrite PCeq. auto. + + (* MBtailcall *) + destruct bb' as [mhd' mbdy' mex']; simpl in *. subst. + inv TBC. inv TIC. inv H0. + + assert (f0 = f) by congruence. subst f0. + assert (NOOV: size_blocks tf.(fn_blocks) <= Ptrofs.max_unsigned). + eapply transf_function_no_overflow; eauto. + exploit Mem.loadv_extends. eauto. eexact H15. auto. simpl. intros [parent' [A B]]. + destruct s1 as [rf|fid]; simpl in H13. + * monadInv H1. + assert (ms' rf = Vptr f' Ptrofs.zero). + { destruct (ms' rf); try discriminate. revert H13. predSpec Ptrofs.eq Ptrofs.eq_spec i Ptrofs.zero; intros; congruence. } + assert (rs2 x = Vptr f' Ptrofs.zero). + { exploit ireg_val; eauto. rewrite H; intros LD; inv LD; auto. } + + assert (f = f1) by congruence. subst f1. clear FIND1. clear H14. + exploit make_epilogue_correct; eauto. intros (rs1 & m1 & U & V & W & X & Y & Z). + exploit exec_straight_body; eauto. + { simpl. eauto. } + intros EXEB. + repeat eexists. + rewrite H6. simpl extract_basic. eauto. + rewrite H7. simpl extract_ctl. simpl. reflexivity. + econstructor; eauto. + { apply agree_set_other. + - econstructor; auto with asmgen. + + apply V. + + intro r. destruct r; apply V; auto. + - eauto with asmgen. } + assert (IR x <> IR GPR12 /\ IR x <> IR GPR32 /\ IR x <> IR GPR16). + { clear - EQ. destruct x; repeat split; try discriminate. + all: unfold ireg_of in EQ; destruct rf; try discriminate. } + Simpl. inv H1. inv H3. rewrite Z; auto; try discriminate. + * monadInv H1. assert (f = f1) by congruence. subst f1. clear FIND1. clear H14. + exploit make_epilogue_correct; eauto. intros (rs1 & m1 & U & V & W & X & Y & Z). + exploit exec_straight_body; eauto. + simpl. eauto. + intros EXEB. + repeat eexists. + rewrite H6. simpl extract_basic. eauto. + rewrite H7. simpl extract_ctl. simpl. reflexivity. + econstructor; eauto. + { apply agree_set_other. + - econstructor; auto with asmgen. + + apply V. + + intro r. destruct r; apply V; auto. + - eauto with asmgen. } + { Simpl. unfold Genv.symbol_address. rewrite symbols_preserved. rewrite H13. auto. } + + (* MBbuiltin (contradiction) *) + assert (MB.exit bb' <> Some (MBbuiltin e l b)) by (apply Hbuiltin). + rewrite <- H in H1. contradict H1; auto. + + (* MBgoto *) + destruct bb' as [mhd' mbdy' mex']; simpl in *. subst. + inv TBC. inv TIC. inv H0. + + assert (f0 = f) by congruence. subst f0. assert (f1 = f) by congruence. subst f1. clear H11. + remember (nextblock tbb rs2) as rs2'. + exploit functions_transl. eapply FIND0. eapply TRANSF0. intros FIND'. + assert (tf = fn) by congruence. subst tf. + exploit find_label_goto_label. + eauto. eauto. + instantiate (2 := rs2'). + { subst. unfold nextblock, incrPC. Simpl. unfold Val.offset_ptr. rewrite PCeq. eauto. } + eauto. + intros (tc' & rs' & GOTO & AT2 & INV). + + eexists. eexists. repeat eexists. repeat split. + rewrite H6. simpl extract_basic. simpl. eauto. + rewrite H7. simpl extract_ctl. simpl. rewrite <- Heqrs2'. eauto. + econstructor; eauto. + rewrite Heqrs2' in INV. unfold nextblock, incrPC in INV. + eapply agree_exten; eauto with asmgen. + assert (forall r : preg, r <> PC -> rs' r = rs2 r). + { intros. destruct r. + - destruct g. all: rewrite INV; Simpl; auto. + - rewrite INV; Simpl; auto. + - contradiction. } + eauto with asmgen. + congruence. + + (* MBcond *) + destruct bb' as [mhd' mbdy' mex']; simpl in *. subst. + inv TBC. inv TIC. inv H0. + + * (* MBcond true *) + assert (f0 = f) by congruence. subst f0. + exploit eval_condition_lessdef. + eapply preg_vals; eauto. + all: eauto. + intros EC. + exploit transl_cbranch_correct_true; eauto. intros (rs' & jmp & A & B & C). + exploit exec_straight_opt_body2. eauto. intros (bdy & EXEB & BTC). + assert (PCeq': rs2 PC = rs' PC). { inv A; auto. erewrite <- exec_straight_pc. 2: eapply H. eauto. } + rewrite PCeq' in PCeq. + assert (f1 = f) by congruence. subst f1. + exploit find_label_goto_label. + 4: eapply H16. 1-2: eauto. instantiate (2 := (nextblock tbb rs')). rewrite nextblock_pc. + unfold Val.offset_ptr. rewrite PCeq. eauto. + intros (tc' & rs3 & GOTOL & TLPC & Hrs3). + exploit functions_transl. eapply FIND1. eapply TRANSF0. intros FIND'. + assert (tf = fn) by congruence. subst tf. + + repeat eexists. + rewrite H6. rewrite <- BTC. rewrite extract_basics_to_code. simpl. rewrite app_nil_r. eauto. + rewrite H7. rewrite <- BTC. rewrite extract_ctl_basics_to_code. simpl extract_ctl. rewrite B. eauto. + + econstructor; eauto. + eapply agree_exten with rs2; eauto with asmgen. + { intros. destruct r; try destruct g; try discriminate. + all: rewrite Hrs3; try discriminate; unfold nextblock, incrPC; Simpl. } + intros. discriminate. + + * (* MBcond false *) + assert (f0 = f) by congruence. subst f0. + exploit eval_condition_lessdef. + eapply preg_vals; eauto. + all: eauto. + intros EC. + + exploit transl_cbranch_correct_false; eauto. intros (rs' & jmp & A & B & C). + exploit exec_straight_opt_body2. eauto. intros (bdy & EXEB & BTC). + assert (PCeq': rs2 PC = rs' PC). { inv A; auto. erewrite <- exec_straight_pc. 2: eapply H. eauto. } + rewrite PCeq' in PCeq. + exploit functions_transl. eapply FIND1. eapply TRANSF0. intros FIND'. + assert (tf = fn) by congruence. subst tf. + + assert (NOOV: size_blocks fn.(fn_blocks) <= Ptrofs.max_unsigned). + eapply transf_function_no_overflow; eauto. + generalize (code_tail_next_int _ _ _ _ NOOV TAIL). intro CT1. + + repeat eexists. + rewrite H6. rewrite <- BTC. rewrite extract_basics_to_code. simpl. rewrite app_nil_r. eauto. + rewrite H7. rewrite <- BTC. rewrite extract_ctl_basics_to_code. simpl extract_ctl. rewrite B. eauto. + + econstructor; eauto. + unfold nextblock, incrPC. Simpl. unfold Val.offset_ptr. rewrite PCeq. econstructor; eauto. + eapply agree_exten with rs2; eauto with asmgen. + { intros. destruct r; try destruct g; try discriminate. + all: rewrite <- C; try discriminate; unfold nextblock, incrPC; Simpl. } + intros. discriminate. + + (* MBjumptable *) + destruct bb' as [mhd' mbdy' mex']; simpl in *. subst. + inv TBC. inv TIC. inv H0. + + assert (f0 = f) by congruence. subst f0. + monadInv H1. + generalize (transf_function_no_overflow _ _ TRANSF0); intro NOOV. + assert (f1 = f) by congruence. subst f1. + exploit find_label_goto_label. 4: eapply H16. 1-2: eauto. instantiate (2 := (nextblock tbb rs2) # GPR62 <- Vundef # GPR63 <- Vundef). + unfold nextblock, incrPC. Simpl. unfold Val.offset_ptr. rewrite PCeq. reflexivity. + exploit functions_transl. eapply FIND0. eapply TRANSF0. intros FIND3. assert (fn = tf) by congruence. subst fn. + + intros [tc' [rs' [A [B C]]]]. + exploit ireg_val; eauto. rewrite H13. intros LD; inv LD. + + repeat eexists. + rewrite H6. simpl extract_basic. simpl. eauto. + rewrite H7. simpl extract_ctl. simpl. Simpl. rewrite <- H1. unfold Mach.label in H14. unfold label. rewrite H14. eapply A. + econstructor; eauto. + eapply agree_undef_regs; eauto. intros. rewrite C; auto with asmgen. + { assert (destroyed_by_jumptable = R62 :: R63 :: nil) by auto. rewrite H2 in H0. simpl in H0. inv H0. + destruct (preg_eq r' GPR63). subst. contradiction. + destruct (preg_eq r' GPR62). subst. contradiction. + destruct r'; Simpl. } + discriminate. + + (* MBreturn *) + destruct bb' as [mhd' mbdy' mex']; simpl in *. subst. + inv TBC. inv TIC. inv H0. + + assert (f0 = f) by congruence. subst f0. + assert (NOOV: size_blocks tf.(fn_blocks) <= Ptrofs.max_unsigned). + eapply transf_function_no_overflow; eauto. + exploit make_epilogue_correct; eauto. intros (rs1 & m1 & U & V & W & X & Y & Z). + exploit exec_straight_body; eauto. + simpl. eauto. + intros EXEB. + assert (f1 = f) by congruence. subst f1. + + repeat eexists. + rewrite H6. simpl extract_basic. eauto. + rewrite H7. simpl extract_ctl. simpl. reflexivity. + econstructor; eauto. + unfold nextblock, incrPC. repeat apply agree_set_other; auto with asmgen. + + - inv MCS. inv MAS. simpl in *. subst. inv Hpstate. + destruct bb' as [hd' bdy' ex']; simpl in *. subst. + monadInv TBC. monadInv TIC. simpl in *. rewrite H5. rewrite H6. + simpl. repeat eexists. + econstructor. 4: instantiate (3 := false). all:eauto. + unfold nextblock, incrPC. Simpl. unfold Val.offset_ptr. rewrite PCeq. + assert (NOOV: size_blocks tf.(fn_blocks) <= Ptrofs.max_unsigned). + eapply transf_function_no_overflow; eauto. + assert (f = f0) by congruence. subst f0. econstructor; eauto. + generalize (code_tail_next_int _ _ _ _ NOOV TAIL). intro CT1. eauto. + eapply agree_exten; eauto. intros. Simpl. + discriminate. +Qed. + +Definition mb_remove_first (bb: MB.bblock) := + {| MB.header := MB.header bb; MB.body := tail (MB.body bb); MB.exit := MB.exit bb |}. + +Lemma exec_straight_body: + forall c c' lc rs1 m1 rs2 m2, + exec_straight tge c rs1 m1 c' rs2 m2 -> + code_to_basics c = Some lc -> + exists l ll, + c = l ++ c' + /\ code_to_basics l = Some ll + /\ exec_body tge ll rs1 m1 = Next rs2 m2. +Proof. + induction c; try (intros; inv H; fail). + intros until m2. intros EXES CTB. inv EXES. + - exists (i1 ::g nil),(i1::nil). repeat (split; simpl; auto). rewrite H6. auto. + - inv CTB. destruct (code_to_basics c); try discriminate. inv H0. + eapply IHc in H7; eauto. destruct H7 as (l' & ll & Hc & CTB & EXECB). subst. + exists (i ::g l'),(i::ll). repeat (split; simpl; auto). + rewrite CTB. auto. + rewrite H1. auto. +Qed. + +Lemma basics_to_code_app: + forall c l x ll, + basics_to_code c = l ++ basics_to_code x -> + code_to_basics l = Some ll -> + c = ll ++ x. +Proof. + intros. apply (f_equal code_to_basics) in H. + erewrite code_to_basics_dist in H; eauto. 2: eapply code_to_basics_id. + rewrite code_to_basics_id in H. inv H. auto. +Qed. + +Lemma basics_to_code_app2: + forall i c l x ll, + (PBasic i) :: basics_to_code c = l ++ basics_to_code x -> + code_to_basics l = Some ll -> + i :: c = ll ++ x. +Proof. + intros until ll. intros. + exploit basics_to_code_app. instantiate (3 := (i::c)). simpl. + all: eauto. +Qed. + +(* Handling the individual instructions of theorem (B) in the above diagram. A bit less cumbersome, but still tough *) +Theorem step_simu_basic: + forall bb bb' s fb sp c ms m rs1 m1 ms' m' bi cs1 tbdy bdy, + MB.header bb = nil -> MB.body bb = bi::(bdy) -> (forall ef args res, MB.exit bb <> Some (MBbuiltin ef args res)) -> + bb' = {| MB.header := nil; MB.body := bdy; MB.exit := MB.exit bb |} -> + basic_step ge s fb sp ms m bi ms' m' -> + pstate cs1 = (State rs1 m1) -> pbody1 cs1 = tbdy -> + match_codestate fb (MB.State s fb sp (bb::c) ms m) cs1 -> + (exists rs2 m2 l cs2 tbdy', + cs2 = {| pstate := (State rs2 m2); pheader := nil; pbody1 := tbdy'; pbody2 := pbody2 cs1; + pctl := pctl cs1; ep := fp_is_parent (ep cs1) bi; rem := rem cs1; cur := cur cs1 |} + /\ tbdy = l ++ tbdy' + /\ exec_body tge l rs1 m1 = Next rs2 m2 + /\ match_codestate fb (MB.State s fb sp (bb'::c) ms' m') cs2). +Proof. + intros until bdy. intros Hheader Hbody Hnobuiltin (* Hnotempty *) Hbb' BSTEP Hpstate Hpbody1 MCS. inv MCS. + simpl in *. inv Hpstate. + rewrite Hbody in TBC. monadInv TBC. + inv BSTEP. + + - (* MBgetstack *) + simpl in EQ0. + unfold Mach.load_stack in H. + exploit Mem.loadv_extends; eauto. intros [v' [A B]]. + rewrite (sp_val _ _ _ AG) in A. + exploit loadind_correct; eauto with asmgen. + intros (rs2 & EXECS & Hrs'1 & Hrs'2). + eapply exec_straight_body in EXECS. + 2: eapply code_to_basics_id; eauto. + destruct EXECS as (l & Hlbi & BTC & CTB & EXECB). + exists rs2, m1, Hlbi. + eexists. eexists. split. instantiate (1 := x). eauto. + repeat (split; auto). + eapply basics_to_code_app; eauto. + remember {| MB.header := _; MB.body := _; MB.exit := _ |} as bb'. + assert (Hheadereq: MB.header bb' = MB.header bb). { subst. simpl. auto. } + subst. simpl in Hheadereq. + + eapply match_codestate_intro; eauto. + { simpl. simpl in EQ. rewrite <- Hheadereq in EQ. assumption. } + eapply agree_set_mreg; eauto with asmgen. + intro Hep. simpl in Hep. + destruct (andb_prop _ _ Hep). clear Hep. + rewrite <- Hheadereq in DXP. subst. rewrite <- DXP. rewrite Hrs'2. reflexivity. + discriminate. apply preg_of_not_FP; assumption. reflexivity. + + - (* MBsetstack *) + simpl in EQ0. + unfold Mach.store_stack in H. + assert (Val.lessdef (ms src) (rs1 (preg_of src))). { eapply preg_val; eauto. } + exploit Mem.storev_extends; eauto. intros [m2' [A B]]. + exploit storeind_correct; eauto with asmgen. + rewrite (sp_val _ _ _ AG) in A. eauto. intros [rs' [P Q]]. + + eapply exec_straight_body in P. + 2: eapply code_to_basics_id; eauto. + destruct P as (l & ll & TBC & CTB & EXECB). + exists rs', m2', ll. + eexists. eexists. split. instantiate (1 := x). eauto. + repeat (split; auto). + eapply basics_to_code_app; eauto. + remember {| MB.header := _; MB.body := _; MB.exit := _ |} as bb'. + subst. + eapply match_codestate_intro; eauto. simpl. simpl in EQ. rewrite Hheader in EQ. auto. + + eapply agree_undef_regs; eauto with asmgen. + simpl; intros. rewrite Q; auto with asmgen. rewrite Hheader in DXP. auto. + - (* MBgetparam *) + simpl in EQ0. + + assert (f0 = f) by congruence; subst f0. + unfold Mach.load_stack in *. + exploit Mem.loadv_extends. eauto. eexact H0. auto. + intros [parent' [A B]]. rewrite (sp_val _ _ _ AG) in A. + exploit lessdef_parent_sp; eauto. clear B; intros B; subst parent'. + exploit Mem.loadv_extends. eauto. eexact H1. auto. + intros [v' [C D]]. + + monadInv EQ0. rewrite Hheader. rewrite Hheader in DXP. + destruct ep0 eqn:EPeq. + + (* RTMP contains parent *) + + exploit loadind_correct. eexact EQ1. + instantiate (2 := rs1). rewrite DXP; eauto. + intros [rs2 [P [Q R]]]. + + eapply exec_straight_body in P. + 2: eapply code_to_basics_id; eauto. + destruct P as (l & ll & BTC & CTB & EXECB). + exists rs2, m1, ll. eexists. + eexists. split. instantiate (1 := x). eauto. + repeat (split; auto). + { eapply basics_to_code_app; eauto. } + remember {| MB.header := _; MB.body := _; MB.exit := _ |} as bb'. + assert (Hheadereq: MB.header bb' = MB.header bb). { subst. simpl. auto. } + subst. + eapply match_codestate_intro; eauto. + + eapply agree_set_mreg. eapply agree_set_mreg; eauto. congruence. auto with asmgen. + simpl; intros. rewrite R; auto with asmgen. + apply preg_of_not_FP; auto. + + (* RTMP does not contain parent *) + + rewrite chunk_of_Tptr in A. + exploit loadind_ptr_correct. eexact A. intros [rs2 [P [Q R]]]. + exploit loadind_correct. eexact EQ1. instantiate (2 := rs2). rewrite Q. eauto. + intros [rs3 [S [T U]]]. + + exploit exec_straight_trans. + eapply P. + eapply S. + intros EXES. + + eapply exec_straight_body in EXES. + 2: simpl. 2: erewrite code_to_basics_id; eauto. + destruct EXES as (l & ll & BTC & CTB & EXECB). + exists rs3, m1, ll. + eexists. eexists. split. instantiate (1 := x). eauto. + repeat (split; auto). + eapply basics_to_code_app2; eauto. + remember {| MB.header := _; MB.body := _; MB.exit := _ |} as bb'. + assert (Hheadereq: MB.header bb' = MB.header bb). { subst. auto. } + subst. + eapply match_codestate_intro; eauto. + eapply agree_set_mreg. eapply agree_set_mreg. eauto. eauto. + instantiate (1 := rs2#FP <- (rs3#FP)). intros. + rewrite Pregmap.gso; auto with asmgen. + congruence. + intros. unfold Pregmap.set. destruct (PregEq.eq r' FP). congruence. auto with asmgen. + simpl; intros. rewrite U; auto with asmgen. + apply preg_of_not_FP; auto. + - (* MBop *) + simpl in EQ0. rewrite Hheader in DXP. + + assert (eval_operation tge sp op (map ms args) m' = Some v). + rewrite <- H. apply eval_operation_preserved. exact symbols_preserved. + exploit eval_operation_lessdef. + eapply preg_vals; eauto. + 2: eexact H0. + all: eauto. + intros [v' [A B]]. rewrite (sp_val _ _ _ AG) in A. + exploit transl_op_correct; eauto. intros [rs2 [P [Q R]]]. + + eapply exec_straight_body in P. + 2: eapply code_to_basics_id; eauto. + destruct P as (l & ll & TBC & CTB & EXECB). + exists rs2, m1, ll. + eexists. eexists. split. instantiate (1 := x). eauto. + repeat (split; auto). + eapply basics_to_code_app; eauto. + remember {| MB.header := _; MB.body := _; MB.exit := _ |} as bb'. + subst. + eapply match_codestate_intro; eauto. simpl. simpl in EQ. rewrite Hheader in EQ. auto. + apply agree_set_undef_mreg with rs1; auto. + apply Val.lessdef_trans with v'; auto. + simpl; intros. destruct (andb_prop _ _ H1); clear H1. + rewrite R; auto. apply preg_of_not_FP; auto. +Local Transparent destroyed_by_op. + destruct op; simpl; auto; congruence. + - (* MBload *) + simpl in EQ0. rewrite Hheader in DXP. + + assert (eval_addressing tge sp addr (map ms args) = Some a). + rewrite <- H. apply eval_addressing_preserved. exact symbols_preserved. + exploit eval_addressing_lessdef. eapply preg_vals; eauto. eexact H1. + intros [a' [A B]]. rewrite (sp_val _ _ _ AG) in A. + exploit Mem.loadv_extends; eauto. intros [v' [C D]]. + exploit transl_load_correct; eauto. + intros [rs2 [P [Q R]]]. + + eapply exec_straight_body in P. + 2: eapply code_to_basics_id; eauto. + destruct P as (l & ll & TBC & CTB & EXECB). + exists rs2, m1, ll. + eexists. eexists. split. instantiate (1 := x). eauto. + repeat (split; auto). + eapply basics_to_code_app; eauto. + remember {| MB.header := _; MB.body := _; MB.exit := _ |} as bb'. + assert (Hheadereq: MB.header bb' = MB.header bb). { subst. auto. } + subst. + eapply match_codestate_intro; eauto. simpl. simpl in EQ. + rewrite <- Hheadereq in EQ. assumption. + eapply agree_set_mreg; eauto with asmgen. + intro Hep. simpl in Hep. + destruct (andb_prop _ _ Hep). clear Hep. + subst. rewrite <- DXP. rewrite R; try discriminate. reflexivity. + apply preg_of_not_FP; assumption. reflexivity. + + - (* notrap1 cannot happen *) + simpl in EQ0. unfold transl_load in EQ0. + destruct addr; simpl in H. + all: unfold transl_load_rrrXS, transl_load_rrr, transl_load_rro in EQ0; + monadInv EQ0; unfold transl_memory_access2XS, transl_memory_access2, transl_memory_access in EQ2; + destruct args as [|h0 t0]; try discriminate; + destruct t0 as [|h1 t1]; try discriminate; + destruct t1 as [|h2 t2]; try discriminate. + + - (* MBload notrap2 TODO *) + simpl in EQ0. rewrite Hheader in DXP. + + assert (eval_addressing tge sp addr (map ms args) = Some a). + rewrite <- H. apply eval_addressing_preserved. exact symbols_preserved. + exploit eval_addressing_lessdef. eapply preg_vals; eauto. eexact H1. + intros [a' [A B]]. rewrite (sp_val _ _ _ AG) in A. + + destruct (Mem.loadv chunk m1 a') as [v' | ] eqn:Hload. + { + exploit transl_load_correct; eauto. + intros [rs2 [P [Q R]]]. + + eapply exec_straight_body in P. + 2: eapply code_to_basics_id; eauto. + destruct P as (l & ll & TBC & CTB & EXECB). + exists rs2, m1, ll. + eexists. eexists. split. instantiate (1 := x). eauto. + repeat (split; auto). + eapply basics_to_code_app; eauto. + eapply match_codestate_intro; eauto. simpl. rewrite Hheader in *. + simpl in EQ. assumption. + + eapply agree_set_undef_mreg; eauto. intros; auto with asmgen. + + simpl. intro. + rewrite R; try congruence. + apply DXP. + destruct ep0; simpl in *; congruence. + apply preg_of_not_FP. + destruct ep0; simpl in *; congruence. + } + { + exploit transl_load_correct_notrap2; eauto. + intros [rs2 [P [Q R]]]. + + eapply exec_straight_body in P. + 2: eapply code_to_basics_id; eauto. + destruct P as (l & ll & TBC & CTB & EXECB). + exists rs2, m1, ll. + eexists. eexists. split. instantiate (1 := x). eauto. + repeat (split; auto). + eapply basics_to_code_app; eauto. + remember {| MB.header := _; MB.body := _; MB.exit := _ |} as bb'. +(* assert (Hheadereq: MB.header bb' = MB.header bb). { subst. auto. } + rewrite <- Hheadereq. *) subst. + eapply match_codestate_intro; eauto. simpl. rewrite Hheader in *. simpl in EQ. assumption. + + eapply agree_set_undef_mreg; eauto. intros; auto with asmgen. + simpl. intro. + rewrite R; try congruence. + apply DXP. + destruct ep0; simpl in *; congruence. + apply preg_of_not_FP. + destruct ep0; simpl in *; congruence. + } + - (* MBstore *) + simpl in EQ0. rewrite Hheader in DXP. + + assert (eval_addressing tge sp addr (map ms args) = Some a). + rewrite <- H. apply eval_addressing_preserved. exact symbols_preserved. + exploit eval_addressing_lessdef. eapply preg_vals; eauto. eexact H1. + intros [a' [A B]]. rewrite (sp_val _ _ _ AG) in A. + assert (Val.lessdef (ms src) (rs1 (preg_of src))). eapply preg_val; eauto. + exploit Mem.storev_extends; eauto. intros [m2' [C D]]. + exploit transl_store_correct; eauto. intros [rs2 [P Q]]. + + eapply exec_straight_body in P. + 2: eapply code_to_basics_id; eauto. + destruct P as (l & ll & TBC & CTB & EXECB). + exists rs2, m2', ll. + eexists. eexists. split. instantiate (1 := x). eauto. + repeat (split; auto). + eapply basics_to_code_app; eauto. + remember {| MB.header := _; MB.body := _; MB.exit := _ |} as bb'. + assert (Hheadereq: MB.header bb' = MB.header bb). { subst. auto. } + subst. + eapply match_codestate_intro; eauto. simpl. simpl in EQ. + rewrite <- Hheadereq in EQ. assumption. + eapply agree_undef_regs; eauto with asmgen. + intro Hep. simpl in Hep. + subst. rewrite <- DXP. rewrite Q; try discriminate. reflexivity. reflexivity. +Qed. + +Lemma exec_body_trans: + forall l l' rs0 m0 rs1 m1 rs2 m2, + exec_body tge l rs0 m0 = Next rs1 m1 -> + exec_body tge l' rs1 m1 = Next rs2 m2 -> + exec_body tge (l++l') rs0 m0 = Next rs2 m2. +Proof. + induction l. + - simpl. congruence. + - intros until m2. intros EXEB1 EXEB2. + inv EXEB1. destruct (exec_basic_instr _) eqn:EBI; try discriminate. + simpl. rewrite EBI. eapply IHl; eauto. +Qed. + +Definition mb_remove_header bb := {| MB.header := nil; MB.body := MB.body bb; MB.exit := MB.exit bb |}. + +Program Definition remove_header tbb := {| header := nil; body := body tbb; exit := exit tbb |}. +Next Obligation. + destruct tbb. simpl. auto. +Qed. + +Inductive exec_header: codestate -> codestate -> Prop := + | exec_header_cons: forall cs1, + exec_header cs1 {| pstate := pstate cs1; pheader := nil; pbody1 := pbody1 cs1; pbody2 := pbody2 cs1; + pctl := pctl cs1; ep := (if pheader cs1 then ep cs1 else false); rem := rem cs1; + cur := cur cs1 |}. + +(* Theorem (A) in the diagram, the easiest of all *) +Theorem step_simu_header: + forall bb s fb sp c ms m rs1 m1 cs1, + pstate cs1 = (State rs1 m1) -> + match_codestate fb (MB.State s fb sp (bb::c) ms m) cs1 -> + (exists cs1', + exec_header cs1 cs1' + /\ match_codestate fb (MB.State s fb sp (mb_remove_header bb::c) ms m) cs1'). +Proof. + intros until cs1. intros Hpstate MCS. + eexists. split; eauto. + econstructor; eauto. + inv MCS. simpl in *. inv Hpstate. + econstructor; eauto. +Qed. + +Lemma step_matchasm_header: + forall fb cs1 cs1' s1, + match_asmstate fb cs1 s1 -> + exec_header cs1 cs1' -> + match_asmstate fb cs1' s1. +Proof. + intros until s1. intros MAS EXH. + inv MAS. inv EXH. + simpl. econstructor; eauto. +Qed. + +(* Theorem (B) in the diagram, using step_simu_basic + induction on the Machblock body *) +Theorem step_simu_body: + forall bb s fb sp c ms m rs1 m1 ms' cs1 m', + MB.header bb = nil -> + (forall ef args res, MB.exit bb <> Some (MBbuiltin ef args res)) -> + body_step ge s fb sp (MB.body bb) ms m ms' m' -> + pstate cs1 = (State rs1 m1) -> + match_codestate fb (MB.State s fb sp (bb::c) ms m) cs1 -> + (exists rs2 m2 cs2 ep, + cs2 = {| pstate := (State rs2 m2); pheader := nil; pbody1 := nil; pbody2 := pbody2 cs1; + pctl := pctl cs1; ep := ep; rem := rem cs1; cur := cur cs1 |} + /\ exec_body tge (pbody1 cs1) rs1 m1 = Next rs2 m2 + /\ match_codestate fb (MB.State s fb sp ({| MB.header := nil; MB.body := nil; MB.exit := MB.exit bb |}::c) ms' m') cs2). +Proof. + intros bb. destruct bb as [hd bdy ex]; simpl; auto. induction bdy as [|bi bdy]. + - intros until m'. intros Hheader Hnobuiltin BSTEP Hpstate MCS. + inv BSTEP. + exists rs1, m1, cs1, (ep cs1). + inv MCS. inv Hpstate. simpl in *. monadInv TBC. repeat (split; simpl; auto). + econstructor; eauto. + - intros until m'. intros Hheader Hnobuiltin BSTEP Hpstate MCS. inv BSTEP. + rename ms' into ms''. rename m' into m''. rename rs' into ms'. rename m'0 into m'. + exploit (step_simu_basic); eauto. simpl. eauto. simpl; auto. simpl; auto. + intros (rs2 & m2 & l & cs2 & tbdy' & Hcs2 & Happ & EXEB & MCS'). + simpl in *. + exploit IHbdy. auto. 2: eapply H6. 3: eapply MCS'. all: eauto. subst; eauto. simpl; auto. + intros (rs3 & m3 & cs3 & ep & Hcs3 & EXEB' & MCS''). + exists rs3, m3, cs3, ep. + repeat (split; simpl; auto). subst. simpl in *. auto. + rewrite Happ. eapply exec_body_trans; eauto. rewrite Hcs2 in EXEB'; simpl in EXEB'. auto. +Qed. + +Lemma exec_body_control: + forall b rs1 m1 rs2 m2 rs3 m3 fn, + exec_body tge (body b) rs1 m1 = Next rs2 m2 -> + exec_control_rel tge fn (exit b) b rs2 m2 rs3 m3 -> + exec_bblock_rel tge fn b rs1 m1 rs3 m3. +Proof. + intros until fn. intros EXEB EXECTL. + econstructor; eauto. inv EXECTL. + unfold exec_bblock. rewrite EXEB. auto. +Qed. + +Definition mbsize (bb: MB.bblock) := (length (MB.body bb) + length_opt (MB.exit bb))%nat. + +Lemma mbsize_eqz: + forall bb, mbsize bb = 0%nat -> MB.body bb = nil /\ MB.exit bb = None. +Proof. + intros. destruct bb as [hd bdy ex]; simpl in *. unfold mbsize in H. + remember (length _) as a. remember (length_opt _) as b. + assert (a = 0%nat) by omega. assert (b = 0%nat) by omega. subst. clear H. + inv H0. inv H1. destruct bdy; destruct ex; auto. + all: try discriminate. +Qed. + +Lemma mbsize_neqz: + forall bb, mbsize bb <> 0%nat -> (MB.body bb <> nil \/ MB.exit bb <> None). +Proof. + intros. destruct bb as [hd bdy ex]; simpl in *. + destruct bdy; destruct ex; try (right; discriminate); try (left; discriminate). + contradict H. unfold mbsize. simpl. auto. +Qed. + +(* Bringing theorems (A), (B) and (C) together, for the case of the absence of builtin instruction *) +(* This more general form is easier to prove, but the actual theorem is step_simulation_bblock further below *) +Lemma step_simulation_bblock': + forall sf f sp bb bb' bb'' rs m rs' m' s'' c S1, + bb' = mb_remove_header bb -> + body_step ge sf f sp (Machblock.body bb') rs m rs' m' -> + bb'' = mb_remove_body bb' -> + (forall ef args res, MB.exit bb'' <> Some (MBbuiltin ef args res)) -> + exit_step return_address_offset ge (Machblock.exit bb'') (Machblock.State sf f sp (bb'' :: c) rs' m') E0 s'' -> + match_states (Machblock.State sf f sp (bb :: c) rs m) S1 -> + exists S2 : state, plus step tge S1 E0 S2 /\ match_states s'' S2. +Proof. + intros until S1. intros Hbb' BSTEP Hbb'' Hbuiltin ESTEP MS. + destruct (mbsize bb) eqn:SIZE. + - apply mbsize_eqz in SIZE. destruct SIZE as (Hbody & Hexit). + destruct bb as [hd bdy ex]; simpl in *; subst. + inv MS. inv AT. exploit transl_blocks_nonil; eauto. intros (tbb & tc' & Htc). subst. rename tc' into tc. + monadInv H2. simpl in *. inv ESTEP. inv BSTEP. + eexists. split. eapply plus_one. + exploit functions_translated; eauto. intros (tf0 & FIND' & TRANSF'). monadInv TRANSF'. + assert (x = tf) by congruence. subst x. + eapply exec_step_internal; eauto. eapply find_bblock_tail; eauto. + unfold exec_bblock. simpl. eauto. + econstructor. eauto. eauto. eauto. + unfold nextblock, incrPC. Simpl. unfold Val.offset_ptr. rewrite <- H. + assert (NOOV: size_blocks tf.(fn_blocks) <= Ptrofs.max_unsigned). + eapply transf_function_no_overflow; eauto. + econstructor; eauto. + generalize (code_tail_next_int _ _ _ _ NOOV H3). intro CT1. eauto. + eapply agree_exten; eauto. intros. Simpl. + intros. discriminate. + - subst. exploit mbsize_neqz. { instantiate (1 := bb). rewrite SIZE. discriminate. } + intros Hnotempty. + + (* initial setting *) + exploit match_state_codestate. + 2: eapply Hnotempty. + all: eauto. + intros (cs1 & fb & f0 & tbb & tc & ep & MCS & MAS & FIND & TLBS & Hbody & Hexit & Hcur & Hrem & Hpstate). + + (* step_simu_header part *) + assert (exists rs1 m1, pstate cs1 = State rs1 m1). { inv MAS. simpl. eauto. } + destruct H as (rs1 & m1 & Hpstate2). subst. + assert (f = fb). { inv MCS. auto. } subst fb. + exploit step_simu_header. + 2: eapply MCS. + all: eauto. + intros (cs1' & EXEH & MCS2). + + (* step_simu_body part *) + assert (Hpstate': pstate cs1' = pstate cs1). { inv EXEH; auto. } + exploit step_simu_body. + 3: eapply BSTEP. + 4: eapply MCS2. + all: eauto. rewrite Hpstate'. eauto. + intros (rs2 & m2 & cs2 & ep' & Hcs2 & EXEB & MCS'). + + (* step_simu_control part *) + assert (exists tf, Genv.find_funct_ptr tge f = Some (Internal tf)). + { exploit functions_translated; eauto. intros (tf & FIND' & TRANSF'). monadInv TRANSF'. eauto. } + destruct H as (tf & FIND'). + assert (exists tex, pbody2 cs1 = extract_basic tex /\ pctl cs1 = extract_ctl tex). + { inv MAS. simpl in *. eauto. } + destruct H as (tex & Hpbody2 & Hpctl). + inv EXEH. simpl in *. + subst. exploit step_simu_control. + 9: eapply MCS'. all: simpl. + 10: eapply ESTEP. + all: simpl; eauto. + rewrite Hpbody2. rewrite Hpctl. + { inv MAS; simpl in *. inv Hpstate2. eapply match_asmstate_some; eauto. + erewrite exec_body_pc; eauto. } + intros (rs3 & m3 & rs4 & m4 & EXEB' & EXECTL' & MS'). + + (* bringing the pieces together *) + exploit exec_body_trans. + eapply EXEB. + eauto. + intros EXEB2. + exploit exec_body_control; eauto. + rewrite <- Hpbody2 in EXEB2. rewrite <- Hbody in EXEB2. eauto. + rewrite Hexit. rewrite Hpctl. eauto. + intros EXECB. inv EXECB. + exists (State rs4 m4). + split; auto. eapply plus_one. rewrite Hpstate2. + assert (exists ofs, rs1 PC = Vptr f ofs). + { rewrite Hpstate2 in MAS. inv MAS. simpl in *. eauto. } + destruct H0 as (ofs & Hrs1pc). + eapply exec_step_internal; eauto. + + (* proving the initial find_bblock *) + rewrite Hpstate2 in MAS. inv MAS. simpl in *. + assert (f1 = f0) by congruence. subst f0. + rewrite PCeq in Hrs1pc. inv Hrs1pc. + exploit functions_translated; eauto. intros (tf1 & FIND'' & TRANS''). rewrite FIND' in FIND''. + inv FIND''. monadInv TRANS''. rewrite TRANSF0 in EQ. inv EQ. + eapply find_bblock_tail; eauto. +Qed. + +Theorem step_simulation_bblock: + forall sf f sp bb ms m ms' m' S2 c, + body_step ge sf f sp (Machblock.body bb) ms m ms' m' -> + (forall ef args res, MB.exit bb <> Some (MBbuiltin ef args res)) -> + exit_step return_address_offset ge (Machblock.exit bb) (Machblock.State sf f sp (bb :: c) ms' m') E0 S2 -> + forall S1', match_states (Machblock.State sf f sp (bb :: c) ms m) S1' -> + exists S2' : state, plus step tge S1' E0 S2' /\ match_states S2 S2'. +Proof. + intros until c. intros BSTEP Hbuiltin ESTEP S1' MS. + eapply step_simulation_bblock'; eauto. + all: destruct bb as [hd bdy ex]; simpl in *; eauto. + inv ESTEP. + - econstructor. inv H; try (econstructor; eauto; fail). + - econstructor. +Qed. + +(** Dealing now with the builtin case *) + +Definition split (c: MB.code) := + match c with + | nil => nil + | bb::c => {| MB.header := MB.header bb; MB.body := MB.body bb; MB.exit := None |} + :: {| MB.header := nil; MB.body := nil; MB.exit := MB.exit bb |} :: c + end. + +Lemma cons_ok_eq3 {A: Type} : + forall (x:A) y z x' y' z', + x = x' -> y = y' -> z = z' -> + OK (x::y::z) = OK (x'::y'::z'). +Proof. + intros. subst. auto. +Qed. + +Lemma transl_blocks_split_builtin: + forall bb c ep f ef args res, + MB.exit bb = Some (MBbuiltin ef args res) -> MB.body bb <> nil -> + transl_blocks f (split (bb::c)) ep = transl_blocks f (bb::c) ep. +Proof. + intros until res. intros Hexit Hbody. simpl split. + unfold transl_blocks. fold transl_blocks. unfold transl_block. + simpl. remember (transl_basic_code _ _ _) as tbc. remember (transl_instr_control _ _) as tbi. + remember (transl_blocks _ _ _) as tlbs. + destruct tbc; destruct tbi; destruct tlbs. + all: try simpl; auto. + - simpl. rewrite Hexit in Heqtbi. simpl in Heqtbi. monadInv Heqtbi. simpl. + unfold gen_bblocks. simpl. destruct l. + + exploit transl_basic_code_nonil; eauto. intro. destruct H. + + simpl. rewrite app_nil_r. apply cons_ok_eq3. all: try eapply bblock_equality. all: simpl; auto. +Qed. + +Lemma transl_code_at_pc_split_builtin: + forall rs f f0 bb c ep tf tc ef args res, + MB.body bb <> nil -> MB.exit bb = Some (MBbuiltin ef args res) -> + transl_code_at_pc ge (rs PC) f f0 (bb :: c) ep tf tc -> + transl_code_at_pc ge (rs PC) f f0 (split (bb :: c)) ep tf tc. +Proof. + intros until res. intros Hbody Hexit AT. inv AT. + econstructor; eauto. erewrite transl_blocks_split_builtin; eauto. +Qed. + +Theorem match_states_split_builtin: + forall sf f sp bb c rs m ef args res S1, + MB.body bb <> nil -> MB.exit bb = Some (MBbuiltin ef args res) -> + match_states (Machblock.State sf f sp (bb :: c) rs m) S1 -> + match_states (Machblock.State sf f sp (split (bb::c)) rs m) S1. +Proof. + intros until S1. intros Hbody Hexit MS. + inv MS. + econstructor; eauto. + eapply transl_code_at_pc_split_builtin; eauto. +Qed. + +Theorem step_simulation_builtin: + forall ef args res bb sf f sp c ms m t S2, + MB.body bb = nil -> MB.exit bb = Some (MBbuiltin ef args res) -> + exit_step return_address_offset ge (MB.exit bb) (Machblock.State sf f sp (bb :: c) ms m) t S2 -> + forall S1', match_states (Machblock.State sf f sp (bb :: c) ms m) S1' -> + exists S2' : state, plus step tge S1' t S2' /\ match_states S2 S2'. +Proof. + intros until S2. intros Hbody Hexit ESTEP S1' MS. + inv MS. inv AT. monadInv H2. monadInv EQ. + rewrite Hbody in EQ0. monadInv EQ0. + rewrite Hexit in EQ. monadInv EQ. + rewrite Hexit in ESTEP. inv ESTEP. inv H4. + + exploit functions_transl; eauto. intro FN. + generalize (transf_function_no_overflow _ _ H1); intro NOOV. + exploit builtin_args_match; eauto. intros [vargs' [P Q]]. + exploit external_call_mem_extends; eauto. + intros [vres' [m2' [A [B [C D]]]]]. + econstructor; split. apply plus_one. + simpl in H3. + eapply exec_step_builtin. eauto. eauto. + eapply find_bblock_tail; eauto. + simpl. eauto. + erewrite <- sp_val by eauto. + eapply eval_builtin_args_preserved with (ge1 := ge); eauto. exact symbols_preserved. + eapply external_call_symbols_preserved; eauto. apply senv_preserved. + eauto. + econstructor; eauto. + instantiate (2 := tf); instantiate (1 := x0). + unfold nextblock, incrPC. rewrite Pregmap.gss. + rewrite set_res_other. rewrite undef_regs_other_2. rewrite Pregmap.gso by congruence. + rewrite <- H. simpl. econstructor; eauto. + eapply code_tail_next_int; eauto. + rewrite preg_notin_charact. intros. auto with asmgen. + auto with asmgen. + apply agree_nextblock. eapply agree_set_res; auto. + eapply agree_undef_regs; eauto. intros. rewrite undef_regs_other_2; auto. + apply Pregmap.gso; auto with asmgen. + congruence. +Qed. + +Lemma next_sep: + forall rs m rs' m', rs = rs' -> m = m' -> Next rs m = Next rs' m'. +Proof. + congruence. +Qed. + +(* Measure to prove finite stuttering, see the other backends *) +Definition measure (s: MB.state) : nat := + match s with + | MB.State _ _ _ _ _ _ => 0%nat + | MB.Callstate _ _ _ _ => 0%nat + | MB.Returnstate _ _ _ => 1%nat + end. + +(* The actual MB.step/AB.step simulation, using the above theorems, plus extra proofs + for the internal and external function cases *) +Theorem step_simulation: + forall S1 t S2, MB.step return_address_offset ge S1 t S2 -> + forall S1' (MS: match_states S1 S1'), + (exists S2', plus step tge S1' t S2' /\ match_states S2 S2') + \/ (measure S2 < measure S1 /\ t = E0 /\ match_states S2 S1')%nat. +Proof. + induction 1; intros. + +- (* bblock *) + left. destruct (Machblock.exit bb) eqn:MBE; try destruct c0. + all: try(inversion H0; subst; inv H2; eapply step_simulation_bblock; + try (rewrite MBE; try discriminate); eauto). + + (* MBbuiltin *) + destruct (MB.body bb) eqn:MBB. + * inv H. eapply step_simulation_builtin; eauto. rewrite MBE. eauto. + * eapply match_states_split_builtin in MS; eauto. + 2: rewrite MBB; discriminate. + simpl split in MS. + rewrite <- MBB in H. + remember {| MB.header := _; MB.body := _; MB.exit := _ |} as bb1. + assert (MB.body bb = MB.body bb1). { subst. simpl. auto. } + rewrite H1 in H. subst. + exploit step_simulation_bblock. eapply H. + discriminate. + simpl. constructor. + eauto. + intros (S2' & PLUS1 & MS'). + rewrite MBE in MS'. + assert (exit_step return_address_offset ge (Some (MBbuiltin e l b)) + (MB.State sf f sp ({| MB.header := nil; MB.body := nil; MB.exit := Some (MBbuiltin e l b) |}::c) + rs' m') t s'). + { inv H0. inv H3. econstructor. econstructor; eauto. } + exploit step_simulation_builtin. + 4: eapply MS'. + all: simpl; eauto. + intros (S3' & PLUS'' & MS''). + exists S3'. split; eauto. + eapply plus_trans. eapply PLUS1. eapply PLUS''. eauto. + + inversion H0. subst. eapply step_simulation_bblock; try (rewrite MBE; try discriminate); eauto. + +- (* internal function *) + inv MS. + exploit functions_translated; eauto. intros [tf [A B]]. monadInv B. + generalize EQ; intros EQ'. monadInv EQ'. + destruct (zlt Ptrofs.max_unsigned (size_blocks x0.(fn_blocks))); inversion EQ1. clear EQ1. subst x0. + unfold Mach.store_stack in *. + exploit Mem.alloc_extends. eauto. eauto. apply Z.le_refl. apply Z.le_refl. + intros [m1' [C D]]. + exploit Mem.storev_extends. eexact D. eexact H1. eauto. eauto. + intros [m2' [F G]]. + simpl chunk_of_type in F. + exploit Mem.storev_extends. eexact G. eexact H2. eauto. eauto. + intros [m3' [P Q]]. + (* Execution of function prologue *) + monadInv EQ0. + set (tfbody := make_prologue f x0) in *. + set (tf := {| fn_sig := MB.fn_sig f; fn_blocks := tfbody |}) in *. + set (rs2 := rs0#FP <- (parent_sp s) #SP <- sp #RTMP <- Vundef). + exploit (Pget_correct tge GPRA RA nil rs2 m2'); auto. + intros (rs' & U' & V'). + exploit (storeind_ptr_correct tge SP (fn_retaddr_ofs f) GPRA nil rs' m2'). + { rewrite chunk_of_Tptr in P. + assert (rs' GPRA = rs0 RA). { apply V'. } + assert (rs' SP = rs2 SP). { apply V'; discriminate. } + rewrite H4. rewrite H3. + rewrite ATLR. + change (rs2 SP) with sp. eexact P. } + intros (rs3 & U & V). + assert (EXEC_PROLOGUE: exists rs3', + exec_straight_blocks tge tf + tf.(fn_blocks) rs0 m' + x0 rs3' m3' + /\ forall r, r <> PC -> rs3' r = rs3 r). + { eexists. split. + - change (fn_blocks tf) with tfbody; unfold tfbody. + econstructor; eauto. unfold exec_bblock. simpl exec_body. + rewrite C. fold sp. rewrite <- (sp_val _ _ _ AG). rewrite chunk_of_Tptr in F. simpl in F. rewrite F. + Simpl. unfold parexec_store_offset. rewrite Ptrofs.of_int64_to_int64. unfold eval_offset. + rewrite chunk_of_Tptr in P. Simpl. rewrite ATLR. unfold Mptr in P. assert (Archi.ptr64 = true) by auto. 2: auto. rewrite H3 in P. rewrite P. + simpl. apply next_sep; eauto. reflexivity. + - intros. destruct V' as (V'' & V'). destruct r. + + Simpl. + destruct (gpreg_eq g0 GPR16). { subst. Simpl. rewrite V; try discriminate. rewrite V''. subst rs2. Simpl. } + destruct (gpreg_eq g0 GPR32). { subst. Simpl. rewrite V; try discriminate. rewrite V'; try discriminate. subst rs2. Simpl. } + destruct (gpreg_eq g0 GPR12). { subst. Simpl. rewrite V; try discriminate. rewrite V'; try discriminate. subst rs2. Simpl. } + destruct (gpreg_eq g0 GPR17). { subst. Simpl. rewrite V; try discriminate. rewrite V'; try discriminate. subst rs2. Simpl. } + Simpl. rewrite V; try discriminate. rewrite V'; try discriminate. subst rs2. Simpl. { destruct g0; try discriminate. contradiction. } + + Simpl. rewrite V; try discriminate. rewrite V'; try discriminate. subst rs2. Simpl. + + contradiction. + } destruct EXEC_PROLOGUE as (rs3' & EXEC_PROLOGUE & Heqrs3'). + exploit exec_straight_steps_2; eauto using functions_transl. + simpl fn_blocks. simpl fn_blocks in g. omega. constructor. + intros (ofs' & X & Y). + left; exists (State rs3' m3'); split. + eapply exec_straight_steps_1; eauto. + simpl fn_blocks. simpl fn_blocks in g. omega. + constructor. + econstructor; eauto. + rewrite X; econstructor; eauto. + apply agree_exten with rs2; eauto with asmgen. + unfold rs2. + apply agree_set_other; auto with asmgen. + apply agree_change_sp with (parent_sp s). + apply agree_undef_regs with rs0. auto. +Local Transparent destroyed_at_function_entry. + simpl; intros; Simpl. + unfold sp; congruence. + + intros. + assert (r <> RTMP). { contradict H3; rewrite H3; unfold data_preg; auto. } + rewrite Heqrs3'. Simpl. rewrite V. inversion V'. rewrite H6. auto. + assert (r <> GPRA). { contradict H3; rewrite H3; unfold data_preg; auto. } + assert (forall r : preg, r <> PC -> r <> GPRA -> rs' r = rs2 r). { apply V'. } + contradict H3; rewrite H3; unfold data_preg; auto. + contradict H3; rewrite H3; unfold data_preg; auto. + contradict H3; rewrite H3; unfold data_preg; auto. + contradict H3; rewrite H3; unfold data_preg; auto. + intros. rewrite Heqrs3'. rewrite V by auto with asmgen. + assert (forall r : preg, r <> PC -> r <> GPRA -> rs' r = rs2 r). { apply V'. } + rewrite H4 by auto with asmgen. reflexivity. discriminate. + +- (* external function *) + inv MS. + exploit functions_translated; eauto. + intros [tf [A B]]. simpl in B. inv B. + exploit extcall_arguments_match; eauto. + intros [args' [C D]]. + exploit external_call_mem_extends; eauto. + intros [res' [m2' [P [Q [R S]]]]]. + left; econstructor; split. + apply plus_one. eapply exec_step_external; eauto. + eapply external_call_symbols_preserved; eauto. apply senv_preserved. + econstructor; eauto. + unfold loc_external_result. + apply agree_set_other; auto. + apply agree_set_pair; auto. + apply agree_undef_caller_save_regs; auto. + +- (* return *) + inv MS. + inv STACKS. simpl in *. + right. split. omega. split. auto. + rewrite <- ATPC in H5. + econstructor; eauto. congruence. +Qed. + +Lemma transf_initial_states: + forall st1, MB.initial_state prog st1 -> + exists st2, AB.initial_state tprog st2 /\ match_states st1 st2. +Proof. + intros. inversion H. unfold ge0 in *. + econstructor; split. + econstructor. + eapply (Genv.init_mem_transf_partial TRANSF); eauto. + replace (Genv.symbol_address (Genv.globalenv tprog) (prog_main tprog) Ptrofs.zero) + with (Vptr fb Ptrofs.zero). + econstructor; eauto. + constructor. + apply Mem.extends_refl. + split. auto. simpl. unfold Vnullptr; destruct Archi.ptr64; congruence. + intros. rewrite Mach.Regmap.gi. auto. + unfold Genv.symbol_address. + rewrite (match_program_main TRANSF). + rewrite symbols_preserved. + unfold ge; rewrite H1. auto. +Qed. + +Lemma transf_final_states: + forall st1 st2 r, + match_states st1 st2 -> MB.final_state st1 r -> AB.final_state st2 r. +Proof. + intros. inv H0. inv H. constructor. assumption. + compute in H1. inv H1. + generalize (preg_val _ _ _ R0 AG). rewrite H2. intros LD; inv LD. auto. +Qed. + +Definition return_address_offset : Machblock.function -> Machblock.code -> ptrofs -> Prop := + Asmblockgenproof0.return_address_offset. + +Theorem transf_program_correct: + forward_simulation (MB.semantics return_address_offset prog) (Asmblock.semantics tprog). +Proof. + eapply forward_simulation_star with (measure := measure). + - apply senv_preserved. + - eexact transf_initial_states. + - eexact transf_final_states. + - exact step_simulation. +Qed. + +End PRESERVATION. -- cgit