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diff --git a/ia32/standard/Conventions1.v b/ia32/standard/Conventions1.v deleted file mode 100644 index d1f7acd0..00000000 --- a/ia32/standard/Conventions1.v +++ /dev/null @@ -1,366 +0,0 @@ -(* *********************************************************************) -(* *) -(* The Compcert verified compiler *) -(* *) -(* Xavier Leroy, INRIA Paris-Rocquencourt *) -(* *) -(* 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. *) -(* *) -(* *********************************************************************) - -(** Function calling conventions and other conventions regarding the use of - machine registers and stack slots. *) - -Require Import Coqlib. -Require Import AST. -Require Import Events. -Require Import Locations. - -(** * Classification of machine registers *) - -(** Machine registers (type [mreg] in module [Locations]) are divided in - the following groups: -- Callee-save registers, whose value is preserved across a function call. -- Caller-save registers that can be modified during a function call. - - We follow the x86-32 application binary interface (ABI) in our choice - of callee- and caller-save registers. -*) - -Definition int_caller_save_regs := AX :: CX :: DX :: nil. - -Definition float_caller_save_regs := X0 :: X1 :: X2 :: X3 :: X4 :: X5 :: X6 :: X7 :: nil. - -Definition int_callee_save_regs := BX :: SI :: DI :: BP :: nil. - -Definition float_callee_save_regs : list mreg := nil. - -Definition destroyed_at_call := - FP0 :: int_caller_save_regs ++ float_caller_save_regs. - -Definition dummy_int_reg := AX. (**r Used in [Regalloc]. *) -Definition dummy_float_reg := X0. (**r Used in [Regalloc]. *) - -(** The [index_int_callee_save] and [index_float_callee_save] associate - a unique positive integer to callee-save registers. This integer is - used in [Stacking] to determine where to save these registers in - the activation record if they are used by the current function. *) - -Definition index_int_callee_save (r: mreg) := - match r with - | BX => 0 | SI => 1 | DI => 2 | BP => 3 | _ => -1 - end. - -Definition index_float_callee_save (r: mreg) := -1. - -Ltac ElimOrEq := - match goal with - | |- (?x = ?y) \/ _ -> _ => - let H := fresh in - (intro H; elim H; clear H; - [intro H; rewrite <- H; clear H | ElimOrEq]) - | |- False -> _ => - let H := fresh in (intro H; contradiction) - end. - -Ltac OrEq := - match goal with - | |- (?x = ?x) \/ _ => left; reflexivity - | |- (?x = ?y) \/ _ => right; OrEq - | |- False => fail - end. - -Ltac NotOrEq := - match goal with - | |- (?x = ?y) \/ _ -> False => - let H := fresh in ( - intro H; elim H; clear H; [intro; discriminate | NotOrEq]) - | |- False -> False => - contradiction - end. - -Lemma index_int_callee_save_pos: - forall r, In r int_callee_save_regs -> index_int_callee_save r >= 0. -Proof. - intro r. simpl; ElimOrEq; unfold index_int_callee_save; omega. -Qed. - -Lemma index_float_callee_save_pos: - forall r, In r float_callee_save_regs -> index_float_callee_save r >= 0. -Proof. - intro r. simpl; ElimOrEq; unfold index_float_callee_save; omega. -Qed. - -Lemma index_int_callee_save_pos2: - forall r, index_int_callee_save r >= 0 -> In r int_callee_save_regs. -Proof. - destruct r; simpl; intro; omegaContradiction || OrEq. -Qed. - -Lemma index_float_callee_save_pos2: - forall r, index_float_callee_save r >= 0 -> In r float_callee_save_regs. -Proof. - unfold index_float_callee_save; intros. omegaContradiction. -Qed. - -Lemma index_int_callee_save_inj: - forall r1 r2, - In r1 int_callee_save_regs -> - In r2 int_callee_save_regs -> - r1 <> r2 -> - index_int_callee_save r1 <> index_int_callee_save r2. -Proof. - intros r1 r2. - simpl; ElimOrEq; ElimOrEq; unfold index_int_callee_save; - intros; congruence. -Qed. - -Lemma index_float_callee_save_inj: - forall r1 r2, - In r1 float_callee_save_regs -> - In r2 float_callee_save_regs -> - r1 <> r2 -> - index_float_callee_save r1 <> index_float_callee_save r2. -Proof. - simpl; intros. contradiction. -Qed. - -(** The following lemmas show that - (destroyed at call, integer callee-save, float callee-save) - is a partition of the set of machine registers. *) - -Lemma int_float_callee_save_disjoint: - list_disjoint int_callee_save_regs float_callee_save_regs. -Proof. - red; intros r1 r2. simpl; ElimOrEq; ElimOrEq; discriminate. -Qed. - -Lemma register_classification: - forall r, - In r destroyed_at_call \/ In r int_callee_save_regs \/ In r float_callee_save_regs. -Proof. - destruct r; - try (left; simpl; OrEq); - try (right; left; simpl; OrEq); - try (right; right; simpl; OrEq). -Qed. - -Lemma int_callee_save_not_destroyed: - forall r, - In r destroyed_at_call -> In r int_callee_save_regs -> False. -Proof. - intros. revert H0 H. simpl. ElimOrEq; NotOrEq. -Qed. - -Lemma float_callee_save_not_destroyed: - forall r, - In r destroyed_at_call -> In r float_callee_save_regs -> False. -Proof. - intros. revert H0 H. simpl. ElimOrEq; NotOrEq. -Qed. - -Lemma int_callee_save_type: - forall r, In r int_callee_save_regs -> mreg_type r = Tany32. -Proof. - intro. simpl; ElimOrEq; reflexivity. -Qed. - -Lemma float_callee_save_type: - forall r, In r float_callee_save_regs -> mreg_type r = Tany64. -Proof. - intro. simpl; ElimOrEq; reflexivity. -Qed. - -Ltac NoRepet := - match goal with - | |- list_norepet nil => - apply list_norepet_nil - | |- list_norepet (?a :: ?b) => - apply list_norepet_cons; [simpl; intuition discriminate | NoRepet] - end. - -Lemma int_callee_save_norepet: - list_norepet int_callee_save_regs. -Proof. - unfold int_callee_save_regs; NoRepet. -Qed. - -Lemma float_callee_save_norepet: - list_norepet float_callee_save_regs. -Proof. - unfold float_callee_save_regs; NoRepet. -Qed. - -(** * Function calling conventions *) - -(** The functions in this section determine the locations (machine registers - and stack slots) used to communicate arguments and results between the - caller and the callee during function calls. These locations are functions - of the signature of the function and of the call instruction. - Agreement between the caller and the callee on the locations to use - is guaranteed by our dynamic semantics for Cminor and RTL, which demand - that the signature of the call instruction is identical to that of the - called function. - - Calling conventions are largely arbitrary: they must respect the properties - proved in this section (such as no overlapping between the locations - of function arguments), but this leaves much liberty in choosing actual - locations. To ensure binary interoperability of code generated by our - compiler with libraries compiled by another compiler, we - implement the standard x86 conventions. *) - -(** ** Location of function result *) - -(** The result value of a function is passed back to the caller in - registers [AX] or [FP0], depending on the type of the returned value. - We treat a function without result as a function with one integer result. *) - -Definition loc_result (s: signature) : list mreg := - match s.(sig_res) with - | None => AX :: nil - | Some (Tint | Tany32) => AX :: nil - | Some (Tfloat | Tsingle) => FP0 :: nil - | Some Tany64 => X0 :: nil - | Some Tlong => DX :: AX :: nil - end. - -(** The result registers have types compatible with that given in the signature. *) - -Lemma loc_result_type: - forall sig, - subtype_list (proj_sig_res' sig) (map mreg_type (loc_result sig)) = true. -Proof. - intros. unfold proj_sig_res', loc_result. destruct (sig_res sig) as [[]|]; auto. -Qed. - -(** The result locations are caller-save registers *) - -Lemma loc_result_caller_save: - forall (s: signature) (r: mreg), - In r (loc_result s) -> In r destroyed_at_call. -Proof. - intros. - assert (r = AX \/ r = DX \/ r = FP0 \/ r = X0). - unfold loc_result in H. destruct (sig_res s) as [[]|]; simpl in H; intuition. - destruct H0 as [A | [A | [A | A]]]; subst r; simpl; OrEq. -Qed. - -(** ** Location of function arguments *) - -(** All arguments are passed on stack. (Snif.) *) - -Fixpoint loc_arguments_rec - (tyl: list typ) (ofs: Z) {struct tyl} : list loc := - match tyl with - | nil => nil - | Tint :: tys => S Outgoing ofs Tint :: loc_arguments_rec tys (ofs + 1) - | Tfloat :: tys => S Outgoing ofs Tfloat :: loc_arguments_rec tys (ofs + 2) - | Tsingle :: tys => S Outgoing ofs Tsingle :: loc_arguments_rec tys (ofs + 1) - | Tlong :: tys => S Outgoing (ofs + 1) Tint :: S Outgoing ofs Tint :: loc_arguments_rec tys (ofs + 2) - | Tany32 :: tys => S Outgoing ofs Tany32 :: loc_arguments_rec tys (ofs + 1) - | Tany64 :: tys => S Outgoing ofs Tany64 :: loc_arguments_rec tys (ofs + 2) - end. - -(** [loc_arguments s] returns the list of locations where to store arguments - when calling a function with signature [s]. *) - -Definition loc_arguments (s: signature) : list loc := - loc_arguments_rec s.(sig_args) 0. - -(** [size_arguments s] returns the number of [Outgoing] slots used - to call a function with signature [s]. *) - -Fixpoint size_arguments_rec - (tyl: list typ) (ofs: Z) {struct tyl} : Z := - match tyl with - | nil => ofs - | ty :: tys => size_arguments_rec tys (ofs + typesize ty) - end. - -Definition size_arguments (s: signature) : Z := - size_arguments_rec s.(sig_args) 0. - -(** Argument locations are either caller-save registers or [Outgoing] - stack slots at nonnegative offsets. *) - -Definition loc_argument_acceptable (l: loc) : Prop := - match l with - | R r => In r destroyed_at_call - | S Outgoing ofs ty => ofs >= 0 /\ ty <> Tlong - | _ => False - end. - -Remark loc_arguments_rec_charact: - forall tyl ofs l, - In l (loc_arguments_rec tyl ofs) -> - match l with - | S Outgoing ofs' ty => ofs' >= ofs /\ ty <> Tlong - | _ => False - end. -Proof. - induction tyl; simpl loc_arguments_rec; intros. -- destruct H. -- assert (REC: forall ofs1, In l (loc_arguments_rec tyl ofs1) -> ofs1 > ofs -> - match l with - | R _ => False - | S Local _ _ => False - | S Incoming _ _ => False - | S Outgoing ofs' ty => ofs' >= ofs /\ ty <> Tlong - end). - { intros. exploit IHtyl; eauto. destruct l; auto. destruct sl; intuition omega -. } - destruct a; simpl in H; repeat (destruct H); - ((eapply REC; eauto; omega) || (split; [omega|congruence])). -Qed. - -Lemma loc_arguments_acceptable: - forall (s: signature) (l: loc), - In l (loc_arguments s) -> loc_argument_acceptable l. -Proof. - unfold loc_arguments; intros. - exploit loc_arguments_rec_charact; eauto. - unfold loc_argument_acceptable. - destruct l; tauto. -Qed. - -Hint Resolve loc_arguments_acceptable: locs. - -(** The offsets of [Outgoing] arguments are below [size_arguments s]. *) - -Remark size_arguments_rec_above: - forall tyl ofs0, ofs0 <= size_arguments_rec tyl ofs0. -Proof. - induction tyl; simpl; intros. - omega. - apply Zle_trans with (ofs0 + typesize a); auto. - generalize (typesize_pos a); omega. -Qed. - -Lemma size_arguments_above: - forall s, size_arguments s >= 0. -Proof. - intros; unfold size_arguments. apply Zle_ge. - apply size_arguments_rec_above. -Qed. - -Lemma loc_arguments_bounded: - forall (s: signature) (ofs: Z) (ty: typ), - In (S Outgoing ofs ty) (loc_arguments s) -> - ofs + typesize ty <= size_arguments s. -Proof. - intros until ty. unfold loc_arguments, size_arguments. generalize (sig_args s) 0. - induction l; simpl; intros. -- contradiction. -- Ltac decomp := - match goal with - | [ H: _ \/ _ |- _ ] => destruct H; decomp - | [ H: S _ _ _ = S _ _ _ |- _ ] => inv H - | _ => idtac - end. - destruct a; simpl in H; decomp; auto; try apply size_arguments_rec_above. - simpl typesize. replace (z + 1 + 1) with (z + 2) by omega. apply size_arguments_rec_above. - simpl typesize. apply Zle_trans with (ofs + 2). omega. apply size_arguments_rec_above. -Qed. - |