From 08efc2a09b850476e39469791650faf99dd06183 Mon Sep 17 00:00:00 2001 From: Xavier Leroy Date: Mon, 24 Feb 2020 13:56:07 +0100 Subject: Platform-independent implementation of Conventions.size_arguments (#222) The "size_arguments" function and its properties can be systematically derived from the "loc_arguments" function and its properties. Before, the RISC-V port used this derivation, and all other ports used hand-written "size_arguments" functions and proofs. This commit moves the definition of "size_arguments" to the platform-independent file backend/Conventions.v, using the systematic derivation, and removes the platform-specific definitions. This reduces code and proof size, and makes it easier to change the calling conventions. --- powerpc/Conventions1.v | 126 ------------------------------------------------- 1 file changed, 126 deletions(-) (limited to 'powerpc/Conventions1.v') diff --git a/powerpc/Conventions1.v b/powerpc/Conventions1.v index 25d9c081..1f048694 100644 --- a/powerpc/Conventions1.v +++ b/powerpc/Conventions1.v @@ -236,33 +236,6 @@ Fixpoint loc_arguments_rec Definition loc_arguments (s: signature) : list (rpair loc) := loc_arguments_rec s.(sig_args) 0 0 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) (ir fr ofs: Z) {struct tyl} : Z := - match tyl with - | nil => ofs - | (Tint | Tany32) :: tys => - match list_nth_z int_param_regs ir with - | None => size_arguments_rec tys ir fr (ofs + 1) - | Some ireg => size_arguments_rec tys (ir + 1) fr ofs - end - | (Tfloat | Tsingle | Tany64) :: tys => - match list_nth_z float_param_regs fr with - | None => size_arguments_rec tys ir fr (align ofs 2 + 2) - | Some freg => size_arguments_rec tys ir (fr + 1) ofs - end - | Tlong :: tys => - let ir := align ir 2 in - match list_nth_z int_param_regs ir, list_nth_z int_param_regs (ir + 1) with - | Some r1, Some r2 => size_arguments_rec tys (ir + 2) fr ofs - | _, _ => size_arguments_rec tys ir fr (align ofs 2 + 2) - end - end. - -Definition size_arguments (s: signature) : Z := - size_arguments_rec s.(sig_args) 0 0 0. - (** Argument locations are either caller-save registers or [Outgoing] stack slots at nonnegative offsets. *) @@ -359,105 +332,6 @@ Qed. Hint Resolve loc_arguments_acceptable: locs. -(** The offsets of [Outgoing] arguments are below [size_arguments s]. *) - -Remark size_arguments_rec_above: - forall tyl ir fr ofs0, - ofs0 <= size_arguments_rec tyl ir fr ofs0. -Proof. - induction tyl; simpl; intros. - omega. - destruct a. - destruct (list_nth_z int_param_regs ir); eauto. apply Z.le_trans with (ofs0 + 1); auto; omega. - destruct (list_nth_z float_param_regs fr); eauto. - apply Z.le_trans with (align ofs0 2). apply align_le; omega. - apply Z.le_trans with (align ofs0 2 + 2); auto; omega. - set (ir' := align ir 2). - destruct (list_nth_z int_param_regs ir'); eauto. - destruct (list_nth_z int_param_regs (ir' + 1)); eauto. - apply Z.le_trans with (align ofs0 2). apply align_le; omega. - apply Z.le_trans with (align ofs0 2 + 2); auto; omega. - apply Z.le_trans with (align ofs0 2). apply align_le; omega. - apply Z.le_trans with (align ofs0 2 + 2); auto; omega. - destruct (list_nth_z float_param_regs fr); eauto. - apply Z.le_trans with (align ofs0 2). apply align_le; omega. - apply Z.le_trans with (align ofs0 2 + 2); auto; omega. - destruct (list_nth_z int_param_regs ir); eauto. apply Z.le_trans with (ofs0 + 1); auto; omega. - destruct (list_nth_z float_param_regs fr); eauto. - apply Z.le_trans with (align ofs0 2). apply align_le; omega. - apply Z.le_trans with (align ofs0 2 + 2); auto; omega. -Qed. - -Lemma size_arguments_above: - forall s, size_arguments s >= 0. -Proof. - intros; unfold size_arguments. apply Z.le_ge. - apply size_arguments_rec_above. -Qed. - -Lemma loc_arguments_bounded: - forall (s: signature) (ofs: Z) (ty: typ), - In (S Outgoing ofs ty) (regs_of_rpairs (loc_arguments s)) -> - ofs + typesize ty <= size_arguments s. -Proof. - intros. - assert (forall tyl ir fr ofs0, - In (S Outgoing ofs ty) (regs_of_rpairs (loc_arguments_rec tyl ir fr ofs0)) -> - ofs + typesize ty <= size_arguments_rec tyl ir fr ofs0). -{ - induction tyl; simpl; intros. - elim H0. - destruct a. -- (* int *) - destruct (list_nth_z int_param_regs ir); destruct H0. - congruence. - eauto. - inv H0. apply size_arguments_rec_above. - eauto. -- (* float *) - destruct (list_nth_z float_param_regs fr); destruct H0. - congruence. - eauto. - inv H0. apply size_arguments_rec_above. eauto. -- (* long *) - set (ir' := align ir 2) in *. - assert (DFL: - In (S Outgoing ofs ty) (regs_of_rpairs - ((if Archi.ptr64 - then One (S Outgoing (align ofs0 2) Tlong) - else Twolong (S Outgoing (align ofs0 2) Tint) - (S Outgoing (align ofs0 2 + 1) Tint)) - :: loc_arguments_rec tyl ir' fr (align ofs0 2 + 2))) -> - ofs + typesize ty <= size_arguments_rec tyl ir' fr (align ofs0 2 + 2)). - { destruct Archi.ptr64; intros IN. - - destruct IN. inv H1. apply size_arguments_rec_above. auto. - - destruct IN. inv H1. transitivity (align ofs0 2 + 2). simpl; omega. apply size_arguments_rec_above. - destruct H1. inv H1. transitivity (align ofs0 2 + 2). simpl; omega. apply size_arguments_rec_above. - auto. } - destruct (list_nth_z int_param_regs ir'); auto. - destruct (list_nth_z int_param_regs (ir' + 1)); auto. - destruct H0. congruence. destruct H0. congruence. eauto. -- (* single *) - destruct (list_nth_z float_param_regs fr); destruct H0. - congruence. - eauto. - inv H0. transitivity (align ofs0 2 + 2). simpl; omega. apply size_arguments_rec_above. - eauto. -- (* any32 *) - destruct (list_nth_z int_param_regs ir); destruct H0. - congruence. - eauto. - inv H0. apply size_arguments_rec_above. - eauto. -- (* any64 *) - destruct (list_nth_z float_param_regs fr); destruct H0. - congruence. - eauto. - inv H0. apply size_arguments_rec_above. eauto. - } - eauto. -Qed. - Lemma loc_arguments_main: loc_arguments signature_main = nil. Proof. -- cgit