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diff --git a/aarch64/Asmgenproof.v b/aarch64/Asmgenproof.v deleted file mode 100644 index dc0bc509..00000000 --- a/aarch64/Asmgenproof.v +++ /dev/null @@ -1,1029 +0,0 @@ -(* *********************************************************************) -(* *) -(* The Compcert verified compiler *) -(* *) -(* Xavier Leroy, Collège de France and INRIA Paris *) -(* *) -(* Copyright Institut National de Recherche en Informatique et en *) -(* Automatique. All rights reserved. This file is distributed *) -(* under the terms of the INRIA Non-Commercial License Agreement. *) -(* *) -(* *********************************************************************) - -(** Correctness proof for AArch64 code generation. *) - -Require Import Coqlib Errors. -Require Import Integers Floats AST Linking. -Require Import Values Memory Events Globalenvs Smallstep. -Require Import Op Locations Mach Conventions Asm. -Require Import Asmgen Asmgenproof0 Asmgenproof1. - -Definition match_prog (p: Mach.program) (tp: Asm.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: Mach.program. -Variable tprog: Asm.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. - -(** * Properties of control flow *) - -Lemma transf_function_no_overflow: - forall f tf, - transf_function f = OK tf -> list_length_z tf.(fn_code) <= Ptrofs.max_unsigned. -Proof. - intros. monadInv H. destruct (zlt Ptrofs.max_unsigned (list_length_z x.(fn_code))); inv EQ0. - lia. -Qed. - -Lemma exec_straight_exec: - forall fb f c ep tf tc c' rs m rs' m', - transl_code_at_pc ge (rs PC) fb f c ep tf tc -> - exec_straight tge tf tc rs m c' rs' m' -> - plus step tge (State rs m) E0 (State rs' m'). -Proof. - intros. inv H. - eapply exec_straight_steps_1; eauto. - eapply transf_function_no_overflow; eauto. - eapply functions_transl; eauto. -Qed. - -Lemma exec_straight_at: - forall fb f c ep tf tc c' ep' tc' rs m rs' m', - transl_code_at_pc ge (rs PC) fb f c ep tf tc -> - transl_code f c' ep' = OK tc' -> - exec_straight tge tf tc rs m tc' rs' m' -> - transl_code_at_pc ge (rs' PC) fb f c' ep' tf tc'. -Proof. - intros. inv H. - exploit exec_straight_steps_2; eauto. - eapply transf_function_no_overflow; eauto. - eapply functions_transl; eauto. - intros [ofs' [PC' CT']]. - rewrite PC'. constructor; auto. -Qed. - -(** The following lemmas show that the translation from Mach to Asm - preserves labels, in the sense that the following diagram commutes: -<< - translation - Mach code ------------------------ Asm instr sequence - | | - | Mach.find_label lbl find_label lbl | - | | - v v - Mach code tail ------------------- Asm instr seq tail - translation ->> - The proof demands many boring lemmas showing that Asm constructor - functions do not introduce new labels. -*) - -Section TRANSL_LABEL. - -Remark loadimm_z_label: forall sz rd l k, tail_nolabel k (loadimm_z sz rd l k). -Proof. - intros; destruct l as [ | [n1 p1] l]; simpl; TailNoLabel. - induction l as [ | [n p] l]; simpl; TailNoLabel. -Qed. - -Remark loadimm_n_label: forall sz rd l k, tail_nolabel k (loadimm_n sz rd l k). -Proof. - intros; destruct l as [ | [n1 p1] l]; simpl; TailNoLabel. - induction l as [ | [n p] l]; simpl; TailNoLabel. -Qed. - -Remark loadimm_label: forall sz rd n k, tail_nolabel k (loadimm sz rd n k). -Proof. - unfold loadimm; intros. destruct Nat.leb; [apply loadimm_z_label|apply loadimm_n_label]. -Qed. -Hint Resolve loadimm_label: labels. - -Remark loadimm32_label: forall r n k, tail_nolabel k (loadimm32 r n k). -Proof. - unfold loadimm32; intros. destruct (is_logical_imm32 n); TailNoLabel. -Qed. -Hint Resolve loadimm32_label: labels. - -Remark loadimm64_label: forall r n k, tail_nolabel k (loadimm64 r n k). -Proof. - unfold loadimm64; intros. destruct (is_logical_imm64 n); TailNoLabel. -Qed. -Hint Resolve loadimm64_label: labels. - -Remark addimm_aux: forall insn rd r1 n k, - (forall rd r1 n, nolabel (insn rd r1 n)) -> - tail_nolabel k (addimm_aux insn rd r1 n k). -Proof. - unfold addimm_aux; intros. - destruct Z.eqb. TailNoLabel. destruct Z.eqb; TailNoLabel. -Qed. - -Remark addimm32_label: forall rd r1 n k, tail_nolabel k (addimm32 rd r1 n k). -Proof. - unfold addimm32; intros. - destruct Int.eq. apply addimm_aux; intros; red; auto. - destruct Int.eq. apply addimm_aux; intros; red; auto. - destruct Int.lt; eapply tail_nolabel_trans; TailNoLabel. -Qed. -Hint Resolve addimm32_label: labels. - -Remark addimm64_label: forall rd r1 n k, tail_nolabel k (addimm64 rd r1 n k). -Proof. - unfold addimm64; intros. - destruct Int64.eq. apply addimm_aux; intros; red; auto. - destruct Int64.eq. apply addimm_aux; intros; red; auto. - destruct Int64.lt; eapply tail_nolabel_trans; TailNoLabel. -Qed. -Hint Resolve addimm64_label: labels. - -Remark logicalimm32_label: forall insn1 insn2 rd r1 n k, - (forall rd r1 n, nolabel (insn1 rd r1 n)) -> - (forall rd r1 r2 s, nolabel (insn2 rd r1 r2 s)) -> - tail_nolabel k (logicalimm32 insn1 insn2 rd r1 n k). -Proof. - unfold logicalimm32; intros. - destruct (is_logical_imm32 n). TailNoLabel. eapply tail_nolabel_trans; TailNoLabel. -Qed. - -Remark logicalimm64_label: forall insn1 insn2 rd r1 n k, - (forall rd r1 n, nolabel (insn1 rd r1 n)) -> - (forall rd r1 r2 s, nolabel (insn2 rd r1 r2 s)) -> - tail_nolabel k (logicalimm64 insn1 insn2 rd r1 n k). -Proof. - unfold logicalimm64; intros. - destruct (is_logical_imm64 n). TailNoLabel. eapply tail_nolabel_trans; TailNoLabel. -Qed. - -Remark move_extended_label: forall rd r1 ex a k, tail_nolabel k (move_extended rd r1 ex a k). -Proof. - unfold move_extended, move_extended_base; intros. destruct Int.eq, ex; TailNoLabel. -Qed. -Hint Resolve move_extended_label: labels. - -Remark arith_extended_label: forall insnX insnS rd r1 r2 ex a k, - (forall rd r1 r2 x, nolabel (insnX rd r1 r2 x)) -> - (forall rd r1 r2 s, nolabel (insnS rd r1 r2 s)) -> - tail_nolabel k (arith_extended insnX insnS rd r1 r2 ex a k). -Proof. - unfold arith_extended; intros. destruct Int.ltu. - TailNoLabel. - destruct ex; simpl; TailNoLabel. -Qed. - -Remark loadsymbol_label: forall r id ofs k, tail_nolabel k (loadsymbol r id ofs k). -Proof. - intros; unfold loadsymbol. - destruct (SelectOp.symbol_is_relocatable id); TailNoLabel. destruct Ptrofs.eq; TailNoLabel. -Qed. -Hint Resolve loadsymbol_label: labels. - -Remark transl_cond_label: forall cond args k c, - transl_cond cond args k = OK c -> tail_nolabel k c. -Proof. - unfold transl_cond; intros; destruct cond; TailNoLabel. -- destruct is_arith_imm32; TailNoLabel. destruct is_arith_imm32; TailNoLabel. eapply tail_nolabel_trans; TailNoLabel. -- destruct is_arith_imm32; TailNoLabel. destruct is_arith_imm32; TailNoLabel. eapply tail_nolabel_trans; TailNoLabel. -- destruct is_logical_imm32; TailNoLabel. eapply tail_nolabel_trans; TailNoLabel. -- destruct is_logical_imm32; TailNoLabel. eapply tail_nolabel_trans; TailNoLabel. -- destruct is_arith_imm64; TailNoLabel. destruct is_arith_imm64; TailNoLabel. eapply tail_nolabel_trans; TailNoLabel. -- destruct is_arith_imm64; TailNoLabel. destruct is_arith_imm64; TailNoLabel. eapply tail_nolabel_trans; TailNoLabel. -- destruct is_logical_imm64; TailNoLabel. eapply tail_nolabel_trans; TailNoLabel. -- destruct is_logical_imm64; TailNoLabel. eapply tail_nolabel_trans; TailNoLabel. -Qed. - -Remark transl_cond_branch_default_label: forall cond args lbl k c, - transl_cond_branch_default cond args lbl k = OK c -> tail_nolabel k c. -Proof. - unfold transl_cond_branch_default; intros. - eapply tail_nolabel_trans; [eapply transl_cond_label;eauto|TailNoLabel]. -Qed. -Hint Resolve transl_cond_branch_default_label: labels. - -Remark transl_cond_branch_label: forall cond args lbl k c, - transl_cond_branch cond args lbl k = OK c -> tail_nolabel k c. -Proof. - unfold transl_cond_branch; intros; destruct args; TailNoLabel; destruct cond; TailNoLabel. -- destruct c0; TailNoLabel. -- destruct c0; TailNoLabel. -- destruct (Int.is_power2 n); TailNoLabel. -- destruct (Int.is_power2 n); TailNoLabel. -- destruct c0; TailNoLabel. -- destruct c0; TailNoLabel. -- destruct (Int64.is_power2' n); TailNoLabel. -- destruct (Int64.is_power2' n); TailNoLabel. -Qed. - -Remark transl_op_label: - forall op args r k c, - transl_op op args r k = OK c -> tail_nolabel k c. -Proof. - unfold transl_op; intros; destruct op; TailNoLabel. -- destruct (preg_of r); try discriminate; destruct (preg_of m); inv H; TailNoLabel. -- destruct (Float.eq_dec n Float.zero); TailNoLabel. -- destruct (Float32.eq_dec n Float32.zero); TailNoLabel. -- apply logicalimm32_label; unfold nolabel; auto. -- apply logicalimm32_label; unfold nolabel; auto. -- apply logicalimm32_label; unfold nolabel; auto. -- unfold shrx32. destruct Int.eq; TailNoLabel. -- apply arith_extended_label; unfold nolabel; auto. -- apply arith_extended_label; unfold nolabel; auto. -- apply logicalimm64_label; unfold nolabel; auto. -- apply logicalimm64_label; unfold nolabel; auto. -- apply logicalimm64_label; unfold nolabel; auto. -- unfold shrx64. destruct Int.eq; TailNoLabel. -- eapply tail_nolabel_trans. eapply transl_cond_label; eauto. TailNoLabel. -- destruct (preg_of r); try discriminate; TailNoLabel; - (eapply tail_nolabel_trans; [eapply transl_cond_label; eauto | TailNoLabel]). -Qed. - -Remark transl_addressing_label: - forall sz addr args insn k c, - transl_addressing sz addr args insn k = OK c -> - (forall ad, nolabel (insn ad)) -> - tail_nolabel k c. -Proof. - unfold transl_addressing; intros; destruct addr; TailNoLabel; - eapply tail_nolabel_trans; TailNoLabel. - eapply tail_nolabel_trans. apply arith_extended_label; unfold nolabel; auto. TailNoLabel. -Qed. - -Remark transl_load_label: - forall chunk addr args dst k c, - transl_load chunk addr args dst k = OK c -> tail_nolabel k c. -Proof. - unfold transl_load; intros; destruct chunk; TailNoLabel; eapply transl_addressing_label; eauto; unfold nolabel; auto. -Qed. - -Remark transl_store_label: - forall chunk addr args src k c, - transl_store chunk addr args src k = OK c -> tail_nolabel k c. -Proof. - unfold transl_store; intros; destruct chunk; TailNoLabel; eapply transl_addressing_label; eauto; unfold nolabel; auto. -Qed. - -Remark indexed_memory_access_label: - forall insn sz base ofs k, - (forall ad, nolabel (insn ad)) -> - tail_nolabel k (indexed_memory_access insn sz base ofs k). -Proof. - unfold indexed_memory_access; intros. destruct offset_representable. - TailNoLabel. - eapply tail_nolabel_trans; TailNoLabel. -Qed. - -Remark loadind_label: - forall base ofs ty dst k c, - loadind base ofs ty dst k = OK c -> tail_nolabel k c. -Proof. - unfold loadind; intros. - destruct ty, (preg_of dst); inv H; apply indexed_memory_access_label; intros; exact I. -Qed. - -Remark storeind_label: - forall src base ofs ty k c, - storeind src base ofs ty k = OK c -> tail_nolabel k c. -Proof. - unfold storeind; intros. - destruct ty, (preg_of src); inv H; apply indexed_memory_access_label; intros; exact I. -Qed. - -Remark loadptr_label: - forall base ofs dst k, tail_nolabel k (loadptr base ofs dst k). -Proof. - intros. apply indexed_memory_access_label. unfold nolabel; auto. -Qed. - -Remark storeptr_label: - forall src base ofs k, tail_nolabel k (storeptr src base ofs k). -Proof. - intros. apply indexed_memory_access_label. unfold nolabel; auto. -Qed. - -Remark make_epilogue_label: - forall f k, tail_nolabel k (make_epilogue f k). -Proof. - unfold make_epilogue; intros. eapply tail_nolabel_trans. apply loadptr_label. TailNoLabel. -Qed. - -Lemma transl_instr_label: - forall f i ep k c, - transl_instr f i ep k = OK c -> - match i with Mlabel lbl => c = Plabel lbl :: k | _ => tail_nolabel k c end. -Proof. - unfold transl_instr; intros; destruct i; TailNoLabel. -- eapply loadind_label; eauto. -- eapply storeind_label; eauto. -- destruct ep. eapply loadind_label; eauto. - eapply tail_nolabel_trans. apply loadptr_label. eapply loadind_label; eauto. -- eapply transl_op_label; eauto. -- eapply transl_load_label; eauto. -- eapply transl_store_label; eauto. -- destruct s0; monadInv H; TailNoLabel. -- destruct s0; monadInv H; (eapply tail_nolabel_trans; [eapply make_epilogue_label|TailNoLabel]). -- eapply transl_cond_branch_label; eauto. -- eapply tail_nolabel_trans; [eapply make_epilogue_label|TailNoLabel]. -Qed. - -Lemma transl_instr_label': - forall lbl f i ep k c, - transl_instr f i ep k = OK c -> - find_label lbl c = if Mach.is_label lbl i then Some k else find_label lbl k. -Proof. - intros. exploit transl_instr_label; eauto. - destruct i; try (intros [A B]; apply B). - intros. subst c. simpl. auto. -Qed. - -Lemma transl_code_label: - forall lbl f c ep tc, - transl_code f c ep = OK tc -> - match Mach.find_label lbl c with - | None => find_label lbl tc = None - | Some c' => exists tc', find_label lbl tc = Some tc' /\ transl_code f c' false = OK tc' - end. -Proof. - induction c; simpl; intros. - inv H. auto. - monadInv H. rewrite (transl_instr_label' lbl _ _ _ _ _ EQ0). - generalize (Mach.is_label_correct lbl a). - destruct (Mach.is_label lbl a); intros. - subst a. simpl in EQ. exists x; auto. - eapply IHc; eauto. -Qed. - -Lemma transl_find_label: - forall lbl f tf, - transf_function f = OK tf -> - match Mach.find_label lbl f.(Mach.fn_code) with - | None => find_label lbl tf.(fn_code) = None - | Some c => exists tc, find_label lbl tf.(fn_code) = Some tc /\ transl_code f c false = OK tc - end. -Proof. - intros. monadInv H. destruct (zlt Ptrofs.max_unsigned (list_length_z x.(fn_code))); inv EQ0. - monadInv EQ. rewrite transl_code'_transl_code in EQ0. unfold fn_code. - simpl. destruct (storeptr_label X30 XSP (fn_retaddr_ofs f) x) as [A B]; rewrite B. - eapply transl_code_label; eauto. -Qed. - -End TRANSL_LABEL. - -(** A valid branch in a piece of Mach code translates to a valid ``go to'' - transition in the generated Asm 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 -> - Mach.find_label lbl f.(Mach.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. rewrite P. rewrite H1. auto. - split. rewrite Pregmap.gss. constructor; auto. - rewrite Ptrofs.unsigned_repr. replace (pos' - 0) with pos' in Q. - auto. lia. - generalize (transf_function_no_overflow _ _ H0). lia. - intros. apply Pregmap.gso; auto. -Qed. - -(** Existence of return addresses *) - -Lemma return_address_exists: - forall f sg ros c, is_tail (Mcall sg ros :: c) f.(Mach.fn_code) -> - exists ra, return_address_offset f c ra. -Proof. - intros. eapply Asmgenproof0.return_address_exists; eauto. -- intros. exploit transl_instr_label; eauto. - destruct i; try (intros [A B]; apply A). intros. subst c0. repeat constructor. -- intros. monadInv H0. - destruct (zlt Ptrofs.max_unsigned (list_length_z x.(fn_code))); inv EQ0. monadInv EQ. - rewrite transl_code'_transl_code in EQ0. - exists x; exists true; split; auto. unfold fn_code. - constructor. apply (storeptr_label X30 XSP (fn_retaddr_ofs f0) x). -- exact transf_function_no_overflow. -Qed. - -(** * Proof of semantic preservation *) - -(** Semantic preservation is proved using simulation diagrams - of the following form. -<< - st1 --------------- st2 - | | - t| *|t - | | - v v - st1'--------------- st2' ->> - The invariant is the [match_states] predicate below, which includes: -- The Asm code pointed by the PC register is the translation of - the current Mach code sequence. -- Mach register values and Asm register values agree. -*) - -Inductive match_states: Mach.state -> Asm.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#X29 = parent_sp s), - match_states (Mach.State s fb sp c ms m) - (Asm.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 (Mach.Callstate s fb ms m) - (Asm.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 (Mach.Returnstate s ms m) - (Asm.State rs m'). - -Lemma exec_straight_steps: - forall s fb f rs1 i c ep tf tc m1' m2 m2' sp ms2, - match_stack ge s -> - Mem.extends m2 m2' -> - Genv.find_funct_ptr ge fb = Some (Internal f) -> - transl_code_at_pc ge (rs1 PC) fb f (i :: c) ep tf tc -> - (forall k c (TR: transl_instr f i ep k = OK c), - exists rs2, - exec_straight tge tf c rs1 m1' k rs2 m2' - /\ agree ms2 sp rs2 - /\ (it1_is_parent ep i = true -> rs2#X29 = parent_sp s)) -> - exists st', - plus step tge (State rs1 m1') E0 st' /\ - match_states (Mach.State s fb sp c ms2 m2) st'. -Proof. - intros. inversion H2. subst. monadInv H7. - exploit H3; eauto. intros [rs2 [A [B C]]]. - exists (State rs2 m2'); split. - eapply exec_straight_exec; eauto. - econstructor; eauto. eapply exec_straight_at; eauto. -Qed. - -Lemma exec_straight_steps_goto: - forall s fb f rs1 i c ep tf tc m1' m2 m2' sp ms2 lbl c', - match_stack ge s -> - Mem.extends m2 m2' -> - Genv.find_funct_ptr ge fb = Some (Internal f) -> - Mach.find_label lbl f.(Mach.fn_code) = Some c' -> - transl_code_at_pc ge (rs1 PC) fb f (i :: c) ep tf tc -> - it1_is_parent ep i = false -> - (forall k c (TR: transl_instr f i ep k = OK c), - exists jmp, exists k', exists rs2, - exec_straight tge tf c rs1 m1' (jmp :: k') rs2 m2' - /\ agree ms2 sp rs2 - /\ exec_instr tge tf jmp rs2 m2' = goto_label tf lbl rs2 m2') -> - exists st', - plus step tge (State rs1 m1') E0 st' /\ - match_states (Mach.State s fb sp c' ms2 m2) st'. -Proof. - intros. inversion H3. subst. monadInv H9. - exploit H5; eauto. intros [jmp [k' [rs2 [A [B C]]]]]. - generalize (functions_transl _ _ _ H7 H8); intro FN. - generalize (transf_function_no_overflow _ _ H8); intro NOOV. - exploit exec_straight_steps_2; eauto. - intros [ofs' [PC2 CT2]]. - exploit find_label_goto_label; eauto. - intros [tc' [rs3 [GOTO [AT' OTH]]]]. - exists (State rs3 m2'); split. - eapply plus_right'. - eapply exec_straight_steps_1; eauto. - econstructor; eauto. - eapply find_instr_tail. eauto. - rewrite C. eexact GOTO. - traceEq. - econstructor; eauto. - apply agree_exten with rs2; auto with asmgen. - congruence. -Qed. - -Lemma exec_straight_opt_steps_goto: - forall s fb f rs1 i c ep tf tc m1' m2 m2' sp ms2 lbl c', - match_stack ge s -> - Mem.extends m2 m2' -> - Genv.find_funct_ptr ge fb = Some (Internal f) -> - Mach.find_label lbl f.(Mach.fn_code) = Some c' -> - transl_code_at_pc ge (rs1 PC) fb f (i :: c) ep tf tc -> - it1_is_parent ep i = false -> - (forall k c (TR: transl_instr f i ep k = OK c), - exists jmp, exists k', exists rs2, - exec_straight_opt tge tf c rs1 m1' (jmp :: k') rs2 m2' - /\ agree ms2 sp rs2 - /\ exec_instr tge tf jmp rs2 m2' = goto_label tf lbl rs2 m2') -> - exists st', - plus step tge (State rs1 m1') E0 st' /\ - match_states (Mach.State s fb sp c' ms2 m2) st'. -Proof. - intros. inversion H3. subst. monadInv H9. - exploit H5; eauto. intros [jmp [k' [rs2 [A [B C]]]]]. - generalize (functions_transl _ _ _ H7 H8); intro FN. - generalize (transf_function_no_overflow _ _ H8); intro NOOV. - inv A. -- exploit find_label_goto_label; eauto. - intros [tc' [rs3 [GOTO [AT' OTH]]]]. - exists (State rs3 m2'); split. - apply plus_one. econstructor; eauto. - eapply find_instr_tail. eauto. - rewrite C. eexact GOTO. - econstructor; eauto. - apply agree_exten with rs2; auto with asmgen. - congruence. -- exploit exec_straight_steps_2; eauto. - intros [ofs' [PC2 CT2]]. - exploit find_label_goto_label; eauto. - intros [tc' [rs3 [GOTO [AT' OTH]]]]. - exists (State rs3 m2'); split. - eapply plus_right'. - eapply exec_straight_steps_1; eauto. - econstructor; eauto. - eapply find_instr_tail. eauto. - rewrite C. eexact GOTO. - traceEq. - econstructor; eauto. - apply agree_exten with rs2; auto with asmgen. - congruence. -Qed. - -(** We need to show that, in the simulation diagram, we cannot - take infinitely many Mach transitions that correspond to zero - transitions on the Asm side. Actually, all Mach transitions - correspond to at least one Asm transition, except the - transition from [Machsem.Returnstate] to [Machsem.State]. - So, the following integer measure will suffice to rule out - the unwanted behaviour. *) - -Definition measure (s: Mach.state) : nat := - match s with - | Mach.State _ _ _ _ _ _ => 0%nat - | Mach.Callstate _ _ _ _ => 0%nat - | Mach.Returnstate _ _ _ => 1%nat - end. - -Remark preg_of_not_X29: forall r, negb (mreg_eq r R29) = true -> IR X29 <> preg_of r. -Proof. - intros. change (IR X29) with (preg_of R29). red; intros. - exploit preg_of_injective; eauto. intros; subst r; discriminate. -Qed. - -Lemma sp_val': forall ms sp rs, agree ms sp rs -> sp = rs XSP. -Proof. - intros. eapply sp_val; eauto. -Qed. - -(** This is the simulation diagram. We prove it by case analysis on the Mach transition. *) - -Theorem step_simulation: - forall S1 t S2, Mach.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; inv MS. - -- (* Mlabel *) - left; eapply exec_straight_steps; eauto; intros. - monadInv TR. econstructor; split. apply exec_straight_one. simpl; eauto. auto. - split. apply agree_nextinstr; auto. simpl; congruence. - -- (* Mgetstack *) - unfold load_stack in H. - exploit Mem.loadv_extends; eauto. intros [v' [A B]]. - rewrite (sp_val _ _ _ AG) in A. - left; eapply exec_straight_steps; eauto. intros. simpl in TR. - exploit loadind_correct; eauto with asmgen. intros [rs' [P [Q R]]]. - exists rs'; split. eauto. - split. eapply agree_set_mreg; eauto with asmgen. congruence. - simpl; congruence. - -- (* Msetstack *) - unfold store_stack in H. - assert (Val.lessdef (rs src) (rs0 (preg_of src))) by (eapply preg_val; eauto). - exploit Mem.storev_extends; eauto. intros [m2' [A B]]. - left; eapply exec_straight_steps; eauto. - rewrite (sp_val _ _ _ AG) in A. intros. simpl in TR. - exploit storeind_correct; eauto with asmgen. intros [rs' [P Q]]. - exists rs'; split. eauto. - split. eapply agree_undef_regs; eauto with asmgen. - simpl; intros. rewrite Q; auto with asmgen. - -- (* Mgetparam *) - assert (f0 = f) by congruence; subst f0. - unfold 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]]. -Opaque loadind. - left; eapply exec_straight_steps; eauto; intros. monadInv TR. - destruct ep. -(* X30 contains parent *) - exploit loadind_correct. eexact EQ. - instantiate (2 := rs0). simpl; rewrite DXP; eauto. simpl; congruence. - intros [rs1 [P [Q R]]]. - exists rs1; split. eauto. - split. eapply agree_set_mreg. eapply agree_set_mreg; eauto. congruence. auto with asmgen. - simpl; intros. rewrite R; auto with asmgen. - apply preg_of_not_X29; auto. -(* X30 does not contain parent *) - exploit loadptr_correct. eexact A. simpl; congruence. intros [rs1 [P [Q R]]]. - exploit loadind_correct. eexact EQ. instantiate (2 := rs1). simpl; rewrite Q. eauto. simpl; congruence. - intros [rs2 [S [T U]]]. - exists rs2; split. eapply exec_straight_trans; eauto. - split. eapply agree_set_mreg. eapply agree_set_mreg. eauto. eauto. - instantiate (1 := rs1#X29 <- (rs2#X29)). intros. - rewrite Pregmap.gso; auto with asmgen. - congruence. - intros. unfold Pregmap.set. destruct (PregEq.eq r' X29). congruence. auto with asmgen. - simpl; intros. rewrite U; auto with asmgen. - apply preg_of_not_X29; auto. - -- (* Mop *) - assert (eval_operation tge sp op (map rs args) m = Some v). - { rewrite <- H. apply eval_operation_preserved. exact symbols_preserved. } - exploit eval_operation_lessdef. eapply preg_vals; eauto. eauto. eexact H0. - intros [v' [A B]]. rewrite (sp_val _ _ _ AG) in A. - left; eapply exec_straight_steps; eauto; intros. simpl in TR. - exploit transl_op_correct; eauto. intros [rs2 [P [Q R]]]. - exists rs2; split. eauto. split. - apply agree_set_undef_mreg with rs0; auto. - apply Val.lessdef_trans with v'; auto. - simpl; intros. InvBooleans. - rewrite R; auto. apply preg_of_not_X29; auto. -Local Transparent destroyed_by_op. - destruct op; try exact I; simpl; congruence. - -- (* Mload *) - assert (Op.eval_addressing tge sp addr (map rs 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]]. - left; eapply exec_straight_steps; eauto; intros. simpl in TR. - exploit transl_load_correct; eauto. intros [rs2 [P [Q R]]]. - exists rs2; split. eauto. - split. eapply agree_set_undef_mreg; eauto. congruence. - simpl; congruence. - -- (* Mstore *) - assert (Op.eval_addressing tge sp addr (map rs 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 (rs src) (rs0 (preg_of src))) by (eapply preg_val; eauto). - exploit Mem.storev_extends; eauto. intros [m2' [C D]]. - left; eapply exec_straight_steps; eauto. - intros. simpl in TR. exploit transl_store_correct; eauto. intros [rs2 [P Q]]. - exists rs2; split. eauto. - split. eapply agree_undef_regs; eauto with asmgen. - simpl; congruence. - -- (* Mcall *) - assert (f0 = f) by congruence. subst f0. - inv AT. - assert (NOOV: list_length_z tf.(fn_code) <= Ptrofs.max_unsigned). - { eapply transf_function_no_overflow; eauto. } - destruct ros as [rf|fid]; simpl in H; monadInv H5. -+ (* Indirect call *) - assert (rs rf = Vptr f' Ptrofs.zero). - { destruct (rs rf); try discriminate. - revert H; predSpec Ptrofs.eq Ptrofs.eq_spec i Ptrofs.zero; intros; congruence. } - assert (rs0 x0 = Vptr f' Ptrofs.zero). - { exploit ireg_val; eauto. rewrite H5; intros LD; inv LD; auto. } - generalize (code_tail_next_int _ _ _ _ NOOV H6). intro CT1. - assert (TCA: transl_code_at_pc ge (Vptr fb (Ptrofs.add ofs Ptrofs.one)) fb f c false tf x). - { econstructor; eauto. } - exploit return_address_offset_correct; eauto. intros; subst ra. - left; econstructor; split. - apply plus_one. eapply exec_step_internal. Simpl. rewrite <- H2; simpl; eauto. - eapply functions_transl; eauto. eapply find_instr_tail; eauto. - simpl. eauto. - econstructor; eauto. - econstructor; eauto. - eapply agree_sp_def; eauto. - simpl. eapply agree_exten; eauto. intros. Simpl. - Simpl. rewrite <- H2. auto. -+ (* Direct call *) - generalize (code_tail_next_int _ _ _ _ NOOV H6). intro CT1. - assert (TCA: transl_code_at_pc ge (Vptr fb (Ptrofs.add ofs Ptrofs.one)) fb f c false tf x). - econstructor; eauto. - exploit return_address_offset_correct; eauto. intros; subst ra. - left; econstructor; split. - apply plus_one. eapply exec_step_internal. eauto. - eapply functions_transl; eauto. eapply find_instr_tail; eauto. - simpl. unfold Genv.symbol_address. rewrite symbols_preserved. rewrite H. eauto. - econstructor; eauto. - econstructor; eauto. - eapply agree_sp_def; eauto. - simpl. eapply agree_exten; eauto. intros. Simpl. - Simpl. rewrite <- H2. auto. - -- (* Mtailcall *) - assert (f0 = f) by congruence. subst f0. - inversion AT; subst. - assert (NOOV: list_length_z tf.(fn_code) <= Ptrofs.max_unsigned). - { eapply transf_function_no_overflow; eauto. } - exploit Mem.loadv_extends. eauto. eexact H1. auto. simpl. intros [parent' [A B]]. - destruct ros as [rf|fid]; simpl in H; monadInv H7. -+ (* Indirect call *) - assert (rs rf = Vptr f' Ptrofs.zero). - { destruct (rs rf); try discriminate. - revert H; predSpec Ptrofs.eq Ptrofs.eq_spec i Ptrofs.zero; intros; congruence. } - assert (rs0 x0 = Vptr f' Ptrofs.zero). - { exploit ireg_val; eauto. rewrite H7; intros LD; inv LD; auto. } - exploit make_epilogue_correct; eauto. intros (rs1 & m1 & U & V & W & X & Y & Z). - exploit exec_straight_steps_2; eauto using functions_transl. - intros (ofs' & P & Q). - left; econstructor; split. - (* execution *) - eapply plus_right'. eapply exec_straight_exec; eauto. - econstructor. eexact P. eapply functions_transl; eauto. eapply find_instr_tail. eexact Q. - simpl. reflexivity. - traceEq. - (* match states *) - econstructor; eauto. - apply agree_set_other; auto with asmgen. - Simpl. rewrite Z by (rewrite <- (ireg_of_eq _ _ EQ1); eauto with asmgen). assumption. -+ (* Direct call *) - exploit make_epilogue_correct; eauto. intros (rs1 & m1 & U & V & W & X & Y & Z). - exploit exec_straight_steps_2; eauto using functions_transl. - intros (ofs' & P & Q). - left; econstructor; split. - (* execution *) - eapply plus_right'. eapply exec_straight_exec; eauto. - econstructor. eexact P. eapply functions_transl; eauto. eapply find_instr_tail. eexact Q. - simpl. reflexivity. - traceEq. - (* match states *) - econstructor; eauto. - apply agree_set_other; auto with asmgen. - Simpl. unfold Genv.symbol_address. rewrite symbols_preserved. rewrite H. auto. - -- (* Mbuiltin *) - inv AT. monadInv H4. - exploit functions_transl; eauto. intro FN. - generalize (transf_function_no_overflow _ _ H3); intro NOOV. - exploit builtin_args_match; eauto. intros [vargs' [P Q]]. - exploit external_call_mem_extends; eauto. - intros [vres' [m2' [A [B [C D]]]]]. - left. econstructor; split. apply plus_one. - eapply exec_step_builtin. eauto. eauto. - eapply find_instr_tail; 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 := x). - unfold nextinstr. rewrite Pregmap.gss. - rewrite set_res_other. rewrite undef_regs_other. - rewrite <- H1. simpl. econstructor; eauto. - eapply code_tail_next_int; eauto. - simpl; intros. destruct H4. congruence. destruct H4. congruence. - exploit list_in_map_inv; eauto. intros (mr & U & V). subst. - auto with asmgen. - auto with asmgen. - apply agree_nextinstr. eapply agree_set_res; auto. - eapply agree_undef_regs; eauto. intros. - simpl. rewrite undef_regs_other_2; auto. Simpl. - congruence. - -- (* Mgoto *) - assert (f0 = f) by congruence. subst f0. - inv AT. monadInv H4. - exploit find_label_goto_label; eauto. intros [tc' [rs' [GOTO [AT2 INV]]]]. - left; exists (State rs' m'); split. - apply plus_one. econstructor; eauto. - eapply functions_transl; eauto. - eapply find_instr_tail; eauto. - simpl; eauto. - econstructor; eauto. - eapply agree_exten; eauto with asmgen. - congruence. - -- (* Mcond true *) - assert (f0 = f) by congruence. subst f0. - exploit eval_condition_lessdef. eapply preg_vals; eauto. eauto. eauto. intros EC. - left; eapply exec_straight_opt_steps_goto; eauto. - intros. simpl in TR. - exploit transl_cond_branch_correct; eauto. intros (rs' & jmp & A & B & C). - exists jmp; exists k; exists rs'. - split. eexact A. - split. apply agree_exten with rs0; auto with asmgen. - exact B. - -- (* Mcond false *) - exploit eval_condition_lessdef. eapply preg_vals; eauto. eauto. eauto. intros EC. - left; eapply exec_straight_steps; eauto. intros. simpl in TR. - exploit transl_cond_branch_correct; eauto. intros (rs' & jmp & A & B & C). - econstructor; split. - eapply exec_straight_opt_right. eexact A. apply exec_straight_one. eexact B. auto. - split. apply agree_exten with rs0; auto. intros. Simpl. - simpl; congruence. - -- (* Mjumptable *) - assert (f0 = f) by congruence. subst f0. - inv AT. monadInv H6. - exploit functions_transl; eauto. intro FN. - generalize (transf_function_no_overflow _ _ H5); intro NOOV. - exploit find_label_goto_label. eauto. eauto. - instantiate (2 := rs0#X16 <- Vundef). - Simpl. eauto. - eauto. - intros [tc' [rs' [A [B C]]]]. - exploit ireg_val; eauto. rewrite H. intros LD; inv LD. - left; econstructor; split. - apply plus_one. econstructor; eauto. - eapply find_instr_tail; eauto. - simpl. Simpl. rewrite <- H9. unfold Mach.label in H0; unfold label; rewrite H0. eexact A. - econstructor; eauto. - eapply agree_undef_regs; eauto. - simpl. intros. rewrite C; auto with asmgen. Simpl. - congruence. - -- (* Mreturn *) - assert (f0 = f) by congruence. subst f0. - inversion AT; subst. simpl in H6; monadInv H6. - assert (NOOV: list_length_z tf.(fn_code) <= 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_steps_2; eauto using functions_transl. - intros (ofs' & P & Q). - left; econstructor; split. - (* execution *) - eapply plus_right'. eapply exec_straight_exec; eauto. - econstructor. eexact P. eapply functions_transl; eauto. eapply find_instr_tail. eexact Q. - simpl. reflexivity. - traceEq. - (* match states *) - econstructor; eauto. - apply agree_set_other; auto with asmgen. - -- (* internal function *) - - exploit functions_translated; eauto. intros [tf [A B]]. monadInv B. - generalize EQ; intros EQ'. monadInv EQ'. - destruct (zlt Ptrofs.max_unsigned (list_length_z x0.(fn_code))); inversion EQ1. clear EQ1. subst x0. - unfold 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]]. - change (chunk_of_type Tptr) with Mint64 in *. - (* Execution of function prologue *) - monadInv EQ0. rewrite transl_code'_transl_code in EQ1. - set (tfbody := Pallocframe (fn_stacksize f) (fn_link_ofs f) :: - storeptr RA XSP (fn_retaddr_ofs f) x0) in *. - set (tf := {| fn_sig := Mach.fn_sig f; fn_code := tfbody |}) in *. - set (rs2 := nextinstr (rs0#X29 <- (parent_sp s) #SP <- sp #X16 <- Vundef)). - exploit (storeptr_correct tge tf XSP (fn_retaddr_ofs f) RA x0 m2' m3' rs2). - simpl preg_of_iregsp. change (rs2 X30) with (rs0 X30). rewrite ATLR. - change (rs2 X2) with sp. eexact P. - simpl; congruence. congruence. - intros (rs3 & U & V). - assert (EXEC_PROLOGUE: - exec_straight tge tf - tf.(fn_code) rs0 m' - x0 rs3 m3'). - { change (fn_code tf) with tfbody; unfold tfbody. - apply exec_straight_step with rs2 m2'. - unfold exec_instr. rewrite C. fold sp. - rewrite <- (sp_val _ _ _ AG). rewrite F. reflexivity. - reflexivity. - eexact U. } - exploit exec_straight_steps_2; eauto using functions_transl. lia. constructor. - intros (ofs' & X & Y). - left; exists (State rs3 m3'); split. - eapply exec_straight_steps_1; eauto. lia. constructor. - econstructor; eauto. - rewrite X; econstructor; eauto. - apply agree_exten with rs2; eauto with asmgen. - unfold rs2. - apply agree_nextinstr. 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. - simpl; intros; Simpl. - unfold sp; congruence. - intros. rewrite V by auto with asmgen. reflexivity. - -- (* external function *) - 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 STACKS. simpl in *. - right. split. lia. split. auto. - rewrite <- ATPC in H5. - econstructor; eauto. congruence. -Qed. - -Lemma transf_initial_states: - forall st1, Mach.initial_state prog st1 -> - exists st2, Asm.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 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 -> Mach.final_state st1 r -> Asm.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. - -Theorem transf_program_correct: - forward_simulation (Mach.semantics return_address_offset prog) (Asm.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. |