diff options
Diffstat (limited to 'ia32/standard/Conventions1.v')
| -rw-r--r-- | ia32/standard/Conventions1.v | 227 |
1 files changed, 66 insertions, 161 deletions
diff --git a/ia32/standard/Conventions1.v b/ia32/standard/Conventions1.v index 49f5da92..cae20f6e 100644 --- a/ia32/standard/Conventions1.v +++ b/ia32/standard/Conventions1.v @@ -21,46 +21,26 @@ Require Import Locations. (** Machine registers (type [mreg] in module [Locations]) are divided in the following groups: -- Temporaries used for spilling, reloading, and parallel move operations. -- Allocatable registers, that can be assigned to RTL pseudo-registers. - These are further divided into: --- Callee-save registers, whose value is preserved across a function call. --- Caller-save registers that can be modified during a function call. +- 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 :: nil. +Definition int_caller_save_regs := AX :: CX :: DX :: nil. -Definition float_caller_save_regs := X0 :: X1 :: X2 :: X3 :: X4 :: X5 :: 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_regs := - int_caller_save_regs ++ float_caller_save_regs. +Definition destroyed_at_call := + FP0 :: int_caller_save_regs ++ float_caller_save_regs. -Definition destroyed_at_call := List.map R destroyed_at_call_regs. - -Definition int_temporaries := IT1 :: IT2 :: nil. - -Definition float_temporaries := FT1 :: FT2 :: nil. - -(** [FP0] is not used for reloading, hence it is not in [float_temporaries], - however it is not allocatable, hence it is in [temporaries]. *) - -Definition temporary_regs := IT1 :: IT2 :: FT1 :: FT2 :: FP0 :: nil. - -Definition temporaries := List.map R temporary_regs. - -Definition destroyed_at_move_regs := FP0 :: nil. - -Definition destroyed_at_move := List.map R destroyed_at_move_regs. - -Definition dummy_int_reg := AX. (**r Used in [Coloring]. *) -Definition dummy_float_reg := X0. (**r Used in [Coloring]. *) +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 @@ -147,7 +127,7 @@ Proof. Qed. (** The following lemmas show that - (temporaries, destroyed at call, integer callee-save, float callee-save) + (destroyed at call, integer callee-save, float callee-save) is a partition of the set of machine registers. *) Lemma int_float_callee_save_disjoint: @@ -158,34 +138,26 @@ Qed. Lemma register_classification: forall r, - (In (R r) temporaries \/ In (R r) destroyed_at_call) \/ - (In r int_callee_save_regs \/ In r float_callee_save_regs). + In r destroyed_at_call \/ In r int_callee_save_regs \/ In r float_callee_save_regs. Proof. destruct r; - try (left; left; simpl; OrEq); - try (left; right; simpl; OrEq); + 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 r) temporaries \/ In (R r) destroyed_at_call -> - ~(In r int_callee_save_regs). + In r destroyed_at_call -> In r int_callee_save_regs -> False. Proof. - intros; red; intros. elim H. - generalize H0. simpl; ElimOrEq; NotOrEq. - generalize H0. simpl; ElimOrEq; NotOrEq. + intros. revert H0 H. simpl. ElimOrEq; NotOrEq. Qed. Lemma float_callee_save_not_destroyed: forall r, - In (R r) temporaries \/ In (R r) destroyed_at_call -> - ~(In r float_callee_save_regs). + In r destroyed_at_call -> In r float_callee_save_regs -> False. Proof. - intros; red; intros. elim H. - generalize H0. simpl; ElimOrEq; NotOrEq. - generalize H0. simpl; ElimOrEq; NotOrEq. + intros. revert H0 H. simpl. ElimOrEq; NotOrEq. Qed. Lemma int_callee_save_type: @@ -244,13 +216,15 @@ Qed. 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) : mreg := +Definition loc_result (s: signature) : list mreg := match s.(sig_res) with - | None => AX - | Some Tint => AX - | Some Tfloat => FP0 + | None => AX :: nil + | Some Tint => AX :: nil + | Some Tfloat => FP0 :: nil + | Some Tlong => DX :: AX :: nil end. +(* (** The result location has the type stated in the signature. *) Lemma loc_result_type: @@ -263,17 +237,18 @@ Proof. destruct t; reflexivity. reflexivity. Qed. +*) -(** The result location is a caller-save register or a temporary *) +(** The result locations are caller-save registers *) Lemma loc_result_caller_save: - forall (s: signature), - In (R (loc_result s)) destroyed_at_call \/ In (R (loc_result s)) temporaries. + forall (s: signature) (r: mreg), + In r (loc_result s) -> In r destroyed_at_call. Proof. - intros; unfold loc_result. - destruct (sig_res s). - destruct t. left; simpl; OrEq. right; simpl; OrEq. - left; simpl; OrEq. + intros. + assert (r = AX \/ r = DX \/ r = FP0). + unfold loc_result in H. destruct (sig_res s); [destruct t|idtac]; simpl in H; intuition. + destruct H0 as [A | [A | A]]; subst r; simpl; OrEq. Qed. (** ** Location of function arguments *) @@ -284,8 +259,9 @@ 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) + | Tint :: tys => S Outgoing ofs Tint :: loc_arguments_rec tys (ofs + 1) + | Tfloat :: tys => S Outgoing ofs Tfloat :: loc_arguments_rec tys (ofs + 2) + | Tlong :: tys => S Outgoing (ofs + 1) Tint :: S Outgoing ofs Tint :: loc_arguments_rec tys (ofs + 2) end. (** [loc_arguments s] returns the list of locations where to store arguments @@ -301,27 +277,19 @@ Fixpoint size_arguments_rec (tyl: list typ) (ofs: Z) {struct tyl} : Z := match tyl with | nil => ofs - | Tint :: tys => size_arguments_rec tys (ofs + 1) - | Tfloat :: tys => size_arguments_rec tys (ofs + 2) + | ty :: tys => size_arguments_rec tys (ofs + typesize ty) end. Definition size_arguments (s: signature) : Z := size_arguments_rec s.(sig_args) 0. -(** A tail-call is possible for a signature if the corresponding - arguments are all passed in registers. *) - -Definition tailcall_possible (s: signature) : Prop := - forall l, In l (loc_arguments s) -> - match l with R _ => True | S _ => False end. - -(** Argument locations are either non-temporary registers or [Outgoing] +(** 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 l temporaries) - | S (Outgoing ofs ty) => ofs >= 0 + | R r => In r destroyed_at_call + | S Outgoing ofs ty => ofs >= 0 /\ ty <> Tlong | _ => False end. @@ -329,62 +297,36 @@ 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 + | S Outgoing ofs' ty => ofs' >= ofs /\ ty <> Tlong | _ => False end. Proof. induction tyl; simpl loc_arguments_rec; intros. - elim H. - destruct a; simpl in H; destruct H. - subst l. omega. - generalize (IHtyl _ _ H). destruct l; auto. destruct s; auto. omega. - subst l. omega. - generalize (IHtyl _ _ H). destruct l; auto. destruct s; auto. omega. + destruct H. + destruct a. +- destruct H. subst l. split. omega. congruence. + exploit IHtyl; eauto. + destruct l; auto. destruct sl; auto. intuition omega. +- destruct H. subst l. split. omega. congruence. + exploit IHtyl; eauto. + destruct l; auto. destruct sl; auto. intuition omega. +- destruct H. subst l; split; [omega|congruence]. + destruct H. subst l; split; [omega|congruence]. + exploit IHtyl; eauto. + destruct l; auto. destruct sl; auto. intuition omega. Qed. Lemma loc_arguments_acceptable: - forall (s: signature) (r: loc), - In r (loc_arguments s) -> loc_argument_acceptable r. + forall (s: signature) (l: loc), + In l (loc_arguments s) -> loc_argument_acceptable l. Proof. unfold loc_arguments; intros. - generalize (loc_arguments_rec_charact _ _ _ H). - destruct r; tauto. -Qed. -Hint Resolve loc_arguments_acceptable: locs. - -(** Arguments are parwise disjoint (in the sense of [Loc.norepet]). *) - -Remark loc_arguments_rec_notin_local: - forall tyl ofs ofs0 ty0, - Loc.notin (S (Local ofs0 ty0)) (loc_arguments_rec tyl ofs). -Proof. - induction tyl; simpl; intros. - auto. - destruct a; simpl; auto. -Qed. - -Remark loc_arguments_rec_notin_outgoing: - forall tyl ofs ofs0 ty0, - ofs0 + typesize ty0 <= ofs -> - Loc.notin (S (Outgoing ofs0 ty0)) (loc_arguments_rec tyl ofs). -Proof. - induction tyl; simpl; intros. - auto. - destruct a. - split. simpl. omega. apply IHtyl. omega. - split. simpl. omega. apply IHtyl. omega. + exploit loc_arguments_rec_charact; eauto. + unfold loc_argument_acceptable. + destruct l; tauto. Qed. -Lemma loc_arguments_norepet: - forall (s: signature), Loc.norepet (loc_arguments s). -Proof. - intros. unfold loc_arguments. generalize (sig_args s) 0. - induction l; simpl; intros. - constructor. - destruct a; constructor. - apply loc_arguments_rec_notin_outgoing. simpl; omega. auto. - apply loc_arguments_rec_notin_outgoing. simpl; omega. auto. -Qed. +Hint Resolve loc_arguments_acceptable: locs. (** The offsets of [Outgoing] arguments are below [size_arguments s]. *) @@ -393,9 +335,8 @@ Remark size_arguments_rec_above: Proof. induction tyl; simpl; intros. omega. - destruct a. - apply Zle_trans with (ofs0 + 1); auto; omega. - apply Zle_trans with (ofs0 + 2); auto; omega. + apply Zle_trans with (ofs0 + typesize a); auto. + generalize (typesize_pos a); omega. Qed. Lemma size_arguments_above: @@ -407,56 +348,20 @@ Qed. Lemma loc_arguments_bounded: forall (s: signature) (ofs: Z) (ty: typ), - In (S (Outgoing ofs ty)) (loc_arguments s) -> + 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. - elim H. - destruct a; simpl in H; destruct H. - inv H. apply size_arguments_rec_above. - auto. - inv H. apply size_arguments_rec_above. + destruct H. + destruct a. + destruct H. inv H. apply size_arguments_rec_above. auto. + destruct H. inv H. apply size_arguments_rec_above. auto. + destruct H. inv H. + simpl typesize. replace (z + 1 + 1) with (z + 2) by omega. apply size_arguments_rec_above. + destruct H. inv H. + simpl typesize. apply Zle_trans with (ofs + 2). omega. apply size_arguments_rec_above. auto. Qed. -(** Temporary registers do not overlap with argument locations. *) - -Lemma loc_arguments_not_temporaries: - forall sig, Loc.disjoint (loc_arguments sig) temporaries. -Proof. - intros; red; intros x1 x2 H. - generalize (loc_arguments_rec_charact _ _ _ H). - destruct x1. tauto. destruct s; intuition. - revert H1. simpl; ElimOrEq; auto. -Qed. -Hint Resolve loc_arguments_not_temporaries: locs. - -(** Argument registers are caller-save. *) -Lemma arguments_caller_save: - forall sig r, - In (R r) (loc_arguments sig) -> In (R r) destroyed_at_call. -Proof. - unfold loc_arguments; intros. - elim (loc_arguments_rec_charact _ _ _ H); simpl. -Qed. - -(** Argument locations agree in number with the function signature. *) - -Lemma loc_arguments_length: - forall sig, - List.length (loc_arguments sig) = List.length sig.(sig_args). -Proof. - intros. unfold loc_arguments. generalize (sig_args sig) 0. - induction l; simpl; intros. auto. destruct a; simpl; decEq; auto. -Qed. - -(** Argument locations agree in types with the function signature. *) - -Lemma loc_arguments_type: - forall sig, List.map Loc.type (loc_arguments sig) = sig.(sig_args). -Proof. - intros. unfold loc_arguments. generalize (sig_args sig) 0. - induction l; simpl; intros. auto. destruct a; simpl; decEq; auto. -Qed. |