From 2517b7385825981d19e3b9cb2dce0fc22578dcb0 Mon Sep 17 00:00:00 2001 From: xleroy Date: Fri, 2 May 2014 14:03:20 +0000 Subject: Preliminary support for EABI-hardfloat calling conventions git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2473 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e --- arm/PrintAsm.ml | 184 ++++++++---- arm/hardfloat/Conventions1.v | 670 +++++++++++++++++++++++++++++++++++++++++++ arm/hardfloat/Stacklayout.v | 132 +++++++++ 3 files changed, 938 insertions(+), 48 deletions(-) create mode 100644 arm/hardfloat/Conventions1.v create mode 100644 arm/hardfloat/Stacklayout.v diff --git a/arm/PrintAsm.ml b/arm/PrintAsm.ml index 66aa908..e1d5eaa 100644 --- a/arm/PrintAsm.ml +++ b/arm/PrintAsm.ml @@ -272,7 +272,7 @@ let print_annot_val oc txt args res = | [IR src], [IR dst] -> if dst = src then 0 else (fprintf oc " mov %a, %a\n" ireg dst ireg src; 1) | [FR src], [FR dst] -> - if dst = src then 0 else (fprintf oc " fcpy %a, %a\n" freg dst freg src; 1) + if dst = src then 0 else (fprintf oc " fcpyd %a, %a\n" freg dst freg src; 1) | _, _ -> assert false (* Handling of memcpy *) @@ -508,53 +508,141 @@ let print_builtin_inline oc name args res = type direction = Incoming | Outgoing -let ireg_param = function - | 0 -> IR0 | 1 -> IR1 | 2 -> IR2 | 3 -> IR3 | _ -> assert false - -let freg_param = function - | 0 -> FR0 | 1 -> FR1 | 2 -> FR2 | 3 -> FR3 | _ -> assert false - -let fixup_double oc dir f i1 i2 = - match dir with - | Incoming -> (* f <- (i1, i2) *) - fprintf oc " fmdrr %a, %a, %a\n" freg f ireg i1 ireg i2 - | Outgoing -> (* (i1, i2) <- f *) - fprintf oc " fmrrd %a, %a, %a\n" ireg i1 ireg i2 freg f - -let fixup_single oc dir f i = - match dir with - | Incoming -> (* f <- i; f <- double_of_single f *) - fprintf oc " fmsr %a, %a\n" freg_single f ireg i; - fprintf oc " fcvtds %a, %a\n" freg f freg_single f - | Outgoing -> (* f <- single_of_double f; i <- f *) - fprintf oc " fcvtsd %a, %a\n" freg_single f freg f; - fprintf oc " fmrs %a, %a\n" ireg i freg_single f - -let fixup_conventions oc dir tyl = - let rec fixup i tyl = - if i >= 4 then 0 else - match tyl with - | [] -> 0 - | Tint :: tyl' -> - fixup (i+1) tyl' - | Tlong :: tyl' -> - fixup (((i + 1) land (-2)) + 2) tyl' - | Tfloat :: tyl' -> - let i = (i + 1) land (-2) in - if i >= 4 then 0 else begin - fixup_double oc dir (freg_param i) (ireg_param i) (ireg_param (i+1)); - 1 + fixup (i+2) tyl' - end - | Tsingle :: tyl' -> - fixup_single oc dir (freg_param i) (ireg_param i); - 2 + fixup (i+1) tyl' - in fixup 0 tyl - -let fixup_arguments oc dir sg = - fixup_conventions oc dir sg.sig_args - -let fixup_result oc dir sg = - fixup_conventions oc dir (proj_sig_res sg :: []) +module FixupEABI = struct + + let ireg_param = function + | 0 -> IR0 | 1 -> IR1 | 2 -> IR2 | 3 -> IR3 | _ -> assert false + + let freg_param = function + | 0 -> FR0 | 1 -> FR1 | 2 -> FR2 | 3 -> FR3 | _ -> assert false + + let fixup_double oc dir f i1 i2 = + match dir with + | Incoming -> (* f <- (i1, i2) *) + fprintf oc " fmdrr %a, %a, %a\n" freg f ireg i1 ireg i2 + | Outgoing -> (* (i1, i2) <- f *) + fprintf oc " fmrrd %a, %a, %a\n" ireg i1 ireg i2 freg f + + let fixup_single oc dir f i = + match dir with + | Incoming -> (* f <- i; f <- double_of_single f *) + fprintf oc " fmsr %a, %a\n" freg_single f ireg i; + fprintf oc " fcvtds %a, %a\n" freg f freg_single f + | Outgoing -> (* f <- single_of_double f; i <- f *) + fprintf oc " fcvtsd %a, %a\n" freg_single f freg f; + fprintf oc " fmrs %a, %a\n" ireg i freg_single f + + let fixup_conventions oc dir tyl = + let rec fixup i tyl = + if i >= 4 then 0 else + match tyl with + | [] -> 0 + | Tint :: tyl' -> + fixup (i+1) tyl' + | Tlong :: tyl' -> + fixup (((i + 1) land (-2)) + 2) tyl' + | Tfloat :: tyl' -> + let i = (i + 1) land (-2) in + if i >= 4 then 0 else begin + fixup_double oc dir (freg_param i) (ireg_param i) (ireg_param (i+1)); + 1 + fixup (i+2) tyl' + end + | Tsingle :: tyl' -> + fixup_single oc dir (freg_param i) (ireg_param i); + 2 + fixup (i+1) tyl' + in fixup 0 tyl + + let fixup_arguments oc dir sg = + fixup_conventions oc dir sg.sig_args + + let fixup_result oc dir sg = + fixup_conventions oc dir (proj_sig_res sg :: []) + +end + +module FixupHF = struct + + type fsize = Single | Double + + let rec find_single used pos = + if pos >= Array.length used then pos + else if used.(pos) then find_single used (pos + 1) + else begin used.(pos) <- true; pos end + + let rec find_double used pos = + if pos + 1 >= Array.length used then pos + else if used.(pos) || used.(pos + 1) then find_double used (pos + 2) + else begin used.(pos) <- true; used.(pos + 1) <- true; pos / 2 end + + let rec fixup_actions used fr tyl = + match tyl with + | [] -> [] + | (Tint | Tlong) :: tyl' -> fixup_actions used fr tyl' + | Tfloat :: tyl' -> + if fr >= 8 then [] else begin + let dr = find_double used 0 in + assert (dr < 8); + (fr, Double, dr) :: fixup_actions used (fr + 1) tyl' + end + | Tsingle :: tyl' -> + if fr >= 8 then [] else begin + let sr = find_single used 0 in + assert (sr < 16); + (fr, Single, sr) :: fixup_actions used (fr + 1) tyl' + end + + let rec fixup_outgoing oc = function + | [] -> 0 + | (fr, Double, dr) :: act -> + if fr = dr then fixup_outgoing oc act else begin + fprintf oc " fcpyd d%d, d%d\n" dr fr; + 1 + fixup_outgoing oc act + end + | (fr, Single, sr) :: act -> + fprintf oc " fcvtsd s%d, d%d\n" sr fr; + 1 + fixup_outgoing oc act + + let rec fixup_incoming oc = function + | [] -> 0 + | (fr, Double, dr) :: act -> + let n = fixup_incoming oc act in + if fr = dr then n else begin + fprintf oc " fcpyd d%d, d%d\n" fr dr; + 1 + n + end + | (fr, Single, sr) :: act -> + let n = fixup_incoming oc act in + fprintf oc " fcvtds d%d, s%d\n" fr sr; + 1 + n + + let fixup_arguments oc dir sg = + if sg.sig_cc.cc_vararg then + FixupEABI.fixup_arguments oc dir sg + else begin + let act = fixup_actions (Array.make 16 false) 0 sg.sig_args in + match dir with + | Outgoing -> fixup_outgoing oc act + | Incoming -> fixup_incoming oc act + end + + let fixup_result oc dir sg = + if sg.sig_cc.cc_vararg then + FixupEABI.fixup_result oc dir sg + else begin + match proj_sig_res sg, dir with + | Tsingle, Outgoing -> + fprintf oc " fcvtsd s0, d0\n"; 1 + | Tsingle, Incoming -> + fprintf oc " fcvtds d0, s0\n"; 1 + | _ -> 0 + end +end + +let (fixup_arguments, fixup_result) = + match Configuration.variant with + | "eabi" -> (FixupEABI.fixup_arguments, FixupEABI.fixup_result) + | "hardfloat" -> (FixupHF.fixup_arguments, FixupHF.fixup_result) + | _ -> assert false (* Printing of instructions *) diff --git a/arm/hardfloat/Conventions1.v b/arm/hardfloat/Conventions1.v new file mode 100644 index 0000000..e3875e7 --- /dev/null +++ b/arm/hardfloat/Conventions1.v @@ -0,0 +1,670 @@ +(* *********************************************************************) +(* *) +(* 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 Locations. + +(** * Classification of machine registers *) + +(** 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. + + We follow the PowerPC application binary interface (ABI) in our choice + of callee- and caller-save registers. +*) + +Definition int_caller_save_regs := + R0 :: R1 :: R2 :: R3 :: R12 :: nil. + +Definition float_caller_save_regs := + F0 :: F1 :: F2 :: F3 :: F4 :: F5 :: F6 :: F7 :: nil. + +Definition int_callee_save_regs := + R4 :: R5 :: R6 :: R7 :: R8 :: R9 :: R10 :: R11 :: nil. + +Definition float_callee_save_regs := + F8 :: F9 :: F10 :: F11 :: F12 :: F13 :: F14 :: F15 :: nil. + +Definition destroyed_at_call := + int_caller_save_regs ++ float_caller_save_regs. + +Definition dummy_int_reg := R0. (**r Used in [Coloring]. *) +Definition dummy_float_reg := F0. (**r Used in [Coloring]. *) + +(** 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 + | R4 => 0 | R5 => 1 | R6 => 2 | R7 => 3 + | R8 => 4 | R9 => 5 | R10 => 6 | R11 => 7 + | _ => -1 + end. + +Definition index_float_callee_save (r: mreg) := + match r with + | F8 => 0 | F9 => 1 | F10 => 2 | F11 => 3 + | F12 => 4 | F13 => 5 | F14 => 6 | F15 => 7 + | _ => -1 + end. + +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. + destruct r; simpl; intro; omegaContradiction || OrEq. +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. + intros r1 r2. + simpl; ElimOrEq; ElimOrEq; unfold index_float_callee_save; + intros; congruence. +Qed. + +(** The following lemmas show that + (temporaries, 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 = Tint. +Proof. + intro. simpl; ElimOrEq; reflexivity. +Qed. + +Lemma float_callee_save_type: + forall r, In r float_callee_save_regs -> mreg_type r = Tfloat. +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. *) + +(** ** Location of function result *) + +(** The result value of a function is passed back to the caller in + registers [R0] or [F0] or [R0,R1], 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 => R0 :: nil + | Some Tint => R0 :: nil + | Some (Tfloat | Tsingle) => F0 :: nil + | Some Tlong => R1 :: R0 :: nil + end. + +(** The result location is a caller-save register or a temporary *) + +Lemma loc_result_caller_save: + forall (s: signature) (r: mreg), + In r (loc_result s) -> In r destroyed_at_call. +Proof. + intros. + assert (r = R0 \/ r = R1 \/ r = F0). + 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 *) + +(** We use the following calling conventions, adapted from the ARM EABI-HF: +- The first 4 integer arguments are passed in registers [R0] to [R3]. +- The first 2 long integer arguments are passed in an aligned pair of + two integer registers. +- The first 8 single- and double-precision float arguments are passed + in registers [F0...F7] +- Extra arguments are passed on the stack, in [Outgoing] slots, consecutively + assigned (1 word for an integer or single argument, 2 words for a float + or a long), starting at word offset 0. + +This convention is not quite that of the ARM EABI-HF, whereas single float +arguments are passed in 32-bit float registers. Unfortunately, +this does not fit the data model of CompCert. In [PrintAsm.ml] +we insert additional code around function calls that moves +data appropriately. *) + +Definition int_param_regs := + R0 :: R1 :: R2 :: R3 :: nil. + +Definition float_param_regs := + F0 :: F1 :: F2 :: F3 :: F4 :: F5 :: F6 :: F7 :: nil. + +Definition ireg_param (n: Z) : mreg := + match list_nth_z int_param_regs n with Some r => r | None => R0 end. + +Definition freg_param (n: Z) : mreg := + match list_nth_z float_param_regs n with Some r => r | None => F0 end. + +Fixpoint loc_arguments_rec + (tyl: list typ) (ir fr ofs: Z) {struct tyl} : list loc := + match tyl with + | nil => nil + | Tint :: tys => + if zlt ir 4 + then R (ireg_param ir) :: loc_arguments_rec tys (ir + 1) fr ofs + else S Outgoing ofs Tint :: loc_arguments_rec tys ir fr (ofs + 1) + | Tfloat :: tys => + if zlt fr 8 + then R (freg_param fr) :: loc_arguments_rec tys ir (fr + 1) ofs + else let ofs := align ofs 2 in + S Outgoing ofs Tfloat :: loc_arguments_rec tys ir fr (ofs + 2) + | Tsingle :: tys => + if zlt fr 8 + then R (freg_param fr) :: loc_arguments_rec tys ir (fr + 1) ofs + else S Outgoing ofs Tsingle :: loc_arguments_rec tys ir fr (ofs + 1) + | Tlong :: tys => + let ir := align ir 2 in + if zlt ir 4 + then R (ireg_param (ir + 1)) :: R (ireg_param ir) :: loc_arguments_rec tys (ir + 2) fr ofs + else let ofs := align ofs 2 in + S Outgoing (ofs + 1) Tint :: S Outgoing ofs Tint :: loc_arguments_rec tys ir fr (ofs + 2) + end. + +(** For variable-argument functions, we use the default ARM EABI (not HF) + calling conventions: +- The first 4 integer arguments are passed in registers [R0] to [R3]. +- The first 2 long integer arguments are passed in an aligned pair of + two integer registers. +- The first 2 double-precision float arguments are passed in [F0] or [F2] +- The first 4 single-precision float arguments are passed in [F0...F3] +- Integer arguments and float arguments are kept in sync so that + they can all be mapped back to [R0...R3] in [PrintAsm.ml]. +- Extra arguments are passed on the stack, in [Outgoing] slots, consecutively + assigned (1 word for an integer or single argument, 2 words for a float + or a long), starting at word offset 0. +*) + +Fixpoint loc_arguments_vararg + (tyl: list typ) (ofs: Z) {struct tyl} : list loc := + match tyl with + | nil => nil + | Tint :: tys => + (if zlt ofs 0 then R (ireg_param (ofs + 4)) else S Outgoing ofs Tint) + :: loc_arguments_vararg tys (ofs + 1) + | Tfloat :: tys => + let ofs := align ofs 2 in + (if zlt ofs 0 then R (freg_param (ofs + 4)) else S Outgoing ofs Tfloat) + :: loc_arguments_vararg tys (ofs + 2) + | Tsingle :: tys => + (if zlt ofs 0 then R (freg_param (ofs + 4)) else S Outgoing ofs Tsingle) + :: loc_arguments_vararg tys (ofs + 1) + | Tlong :: tys => + let ofs := align ofs 2 in + (if zlt ofs 0 then R (ireg_param (ofs+1+4)) else S Outgoing (ofs+1) Tint) + :: (if zlt ofs 0 then R (ireg_param (ofs+4)) else S Outgoing ofs Tint) + :: loc_arguments_vararg 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 := + if s.(sig_cc).(cc_vararg) + then loc_arguments_vararg s.(sig_args) (-4) + else 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 :: tys => + if zlt ir 4 + then size_arguments_rec tys (ir + 1) fr ofs + else size_arguments_rec tys ir fr (ofs + 1) + | Tfloat :: tys => + if zlt fr 8 + then size_arguments_rec tys ir (fr + 1) ofs + else size_arguments_rec tys ir fr (align ofs 2 + 2) + | Tsingle :: tys => + if zlt fr 8 + then size_arguments_rec tys ir (fr + 1) ofs + else size_arguments_rec tys ir fr (ofs + 1) + | Tlong :: tys => + let ir := align ir 2 in + if zlt ir 4 + then size_arguments_rec tys (ir + 2) fr ofs + else size_arguments_rec tys ir fr (align ofs 2 + 2) + end. + +Fixpoint size_arguments_vararg (tyl: list typ) (ofs: Z) {struct tyl} : Z := + match tyl with + | nil => Zmax 0 ofs + | (Tint | Tsingle) :: tys => size_arguments_vararg tys (ofs + 1) + | (Tfloat | Tlong) :: tys => size_arguments_vararg tys (align ofs 2 + 2) + end. + +Definition size_arguments (s: signature) : Z := + if s.(sig_cc).(cc_vararg) + then size_arguments_vararg s.(sig_args) (-4) + else size_arguments_rec s.(sig_args) 0 0 0. + +(** Argument locations are either non-temporary 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 ireg_param_in_params: forall n, In (ireg_param n) int_param_regs. +Proof. + unfold ireg_param; intros. + destruct (list_nth_z int_param_regs n) as [r|] eqn:NTH. + eapply list_nth_z_in; eauto. + simpl; auto. +Qed. + +Remark freg_param_in_params: forall n, In (freg_param n) float_param_regs. +Proof. + unfold freg_param; intros. + destruct (list_nth_z float_param_regs n) as [r|] eqn:NTH. + eapply list_nth_z_in; eauto. + simpl; auto. +Qed. + +Remark loc_arguments_rec_charact: + forall tyl ir fr ofs l, + In l (loc_arguments_rec tyl ir fr ofs) -> + match l with + | R r => In r int_param_regs \/ In r float_param_regs + | S Outgoing ofs' ty => ofs' >= ofs /\ ty <> Tlong + | S _ _ _ => False + end. +Proof. + assert (INCR: forall l ofs1 ofs2, + match l with + | R r => In r int_param_regs \/ In r float_param_regs + | S Outgoing ofs' ty => ofs' >= ofs2 /\ ty <> Tlong + | S _ _ _ => False + end -> + ofs1 <= ofs2 -> + match l with + | R r => In r int_param_regs \/ In r float_param_regs + | S Outgoing ofs' ty => ofs' >= ofs1 /\ ty <> Tlong + | S _ _ _ => False + end). + { + intros. destruct l; auto. destruct sl; auto. intuition omega. + } + induction tyl; simpl loc_arguments_rec; intros. + elim H. + destruct a. +- (* int *) + destruct (zlt ir 4); destruct H. + subst. left; apply ireg_param_in_params. + eapply IHtyl; eauto. + subst. split; [omega | congruence]. + eapply INCR. eapply IHtyl; eauto. omega. +- (* float *) + destruct (zlt fr 8); destruct H. + subst. right; apply freg_param_in_params. + eapply IHtyl; eauto. + subst. split. apply Zle_ge. apply align_le. omega. congruence. + eapply INCR. eapply IHtyl; eauto. + apply Zle_trans with (align ofs 2). apply align_le; omega. omega. +- (* long *) + set (ir' := align ir 2) in *. + assert (ofs <= align ofs 2) by (apply align_le; omega). + destruct (zlt ir' 4). + destruct H. subst l; left; apply ireg_param_in_params. + destruct H. subst l; left; apply ireg_param_in_params. + eapply IHtyl; eauto. + destruct H. subst l; split; [ omega | congruence ]. + destruct H. subst l; split; [ omega | congruence ]. + eapply INCR. eapply IHtyl; eauto. omega. +- (* single *) + destruct (zlt fr 8); destruct H. + subst. right; apply freg_param_in_params. + eapply IHtyl; eauto. + subst. split; [omega | congruence]. + eapply INCR. eapply IHtyl; eauto. omega. +Qed. + +Remark loc_arguments_vararg_charact: + forall tyl ofs l, + In l (loc_arguments_vararg tyl ofs) -> + match l with + | R r => In r int_param_regs \/ In r float_param_regs + | S Outgoing ofs' ty => ofs' >= Zmax 0 ofs /\ ty <> Tlong + | S _ _ _ => False + end. +Proof. + assert (INCR: forall l ofs1 ofs2, + match l with + | R r => In r int_param_regs \/ In r float_param_regs + | S Outgoing ofs' ty => ofs' >= Zmax 0 ofs2 /\ ty <> Tlong + | S _ _ _ => False + end -> + ofs1 <= ofs2 -> + match l with + | R r => In r int_param_regs \/ In r float_param_regs + | S Outgoing ofs' ty => ofs' >= Zmax 0 ofs1 /\ ty <> Tlong + | S _ _ _ => False + end). + { + intros. destruct l; auto. destruct sl; auto. intuition xomega. + } + induction tyl; simpl loc_arguments_vararg; intros. + elim H. + destruct a. +- (* int *) + destruct H. + destruct (zlt ofs 0); subst l. + left; apply ireg_param_in_params. + split. xomega. congruence. + eapply INCR. eapply IHtyl; eauto. omega. +- (* float *) + set (ofs' := align ofs 2) in *. + assert (ofs <= ofs') by (apply align_le; omega). + destruct H. + destruct (zlt ofs' 0); subst l. + right; apply freg_param_in_params. + split. xomega. congruence. + eapply INCR. eapply IHtyl; eauto. omega. +- (* long *) + set (ofs' := align ofs 2) in *. + assert (ofs <= ofs') by (apply align_le; omega). + destruct H. + destruct (zlt ofs' 0); subst l. + left; apply ireg_param_in_params. + split. xomega. congruence. + destruct H. + destruct (zlt ofs' 0); subst l. + left; apply ireg_param_in_params. + split. xomega. congruence. + eapply INCR. eapply IHtyl; eauto. omega. +- (* single *) + destruct H. + destruct (zlt ofs 0); subst l. + right; apply freg_param_in_params. + split. xomega. congruence. + eapply INCR. eapply IHtyl; eauto. omega. +Qed. + +Lemma loc_arguments_acceptable: + forall (s: signature) (l: loc), + In l (loc_arguments s) -> loc_argument_acceptable l. +Proof. + unfold loc_arguments; intros. + assert (forall r, In r int_param_regs \/ In r float_param_regs -> In r destroyed_at_call). + { + intros. elim H0; simpl; ElimOrEq; OrEq. + } + red. destruct (cc_vararg (sig_cc s)). + exploit loc_arguments_vararg_charact; eauto. + destruct l; auto. + exploit loc_arguments_rec_charact; eauto. + destruct l; auto. +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 (zlt ir 4); eauto. apply Zle_trans with (ofs0 + 1); auto; omega. + destruct (zlt fr 8); eauto. + apply Zle_trans with (align ofs0 2). apply align_le; omega. + apply Zle_trans with (align ofs0 2 + 2); auto; omega. + set (ir' := align ir 2). + destruct (zlt ir' 4); eauto. + apply Zle_trans with (align ofs0 2). apply align_le; omega. + apply Zle_trans with (align ofs0 2 + 2); auto; omega. + destruct (zlt fr 8); eauto. + apply Zle_trans with (ofs0 + 1); eauto. omega. +Qed. + +Remark size_arguments_vararg_above: + forall tyl ofs0, + Zmax 0 ofs0 <= size_arguments_vararg tyl ofs0. +Proof. + induction tyl; simpl; intros. + omega. + destruct a; (eapply Zle_trans; [idtac|eauto]). + xomega. + assert (ofs0 <= align ofs0 2) by (apply align_le; omega). xomega. + assert (ofs0 <= align ofs0 2) by (apply align_le; omega). xomega. + xomega. +Qed. + +Lemma size_arguments_above: + forall s, size_arguments s >= 0. +Proof. + intros; unfold size_arguments. destruct (cc_vararg (sig_cc s)). + apply Zle_ge. change 0 with (Zmax 0 (-4)). apply size_arguments_vararg_above. + apply Zle_ge. apply size_arguments_rec_above. +Qed. + +Lemma loc_arguments_rec_bounded: + forall ofs ty tyl ir fr ofs0, + In (S Outgoing ofs ty) (loc_arguments_rec tyl ir fr ofs0) -> + ofs + typesize ty <= size_arguments_rec tyl ir fr ofs0. +Proof. + induction tyl; simpl; intros. + elim H. + destruct a. +- (* int *) + destruct (zlt ir 4); destruct H. + discriminate. + eauto. + inv H. apply size_arguments_rec_above. + eauto. +- (* float *) + destruct (zlt fr 8); destruct H. + discriminate. + eauto. + inv H. apply size_arguments_rec_above. + eauto. +- (* long *) + destruct (zlt (align ir 2) 4). + destruct H. discriminate. destruct H. discriminate. eauto. + destruct H. inv H. + rewrite <- Zplus_assoc. simpl. apply size_arguments_rec_above. + destruct H. inv H. + eapply Zle_trans. 2: apply size_arguments_rec_above. simpl; omega. + eauto. +- (* float *) + destruct (zlt fr 8); destruct H. + discriminate. + eauto. + inv H. apply size_arguments_rec_above. + eauto. +Qed. + +Lemma loc_arguments_vararg_bounded: + forall ofs ty tyl ofs0, + In (S Outgoing ofs ty) (loc_arguments_vararg tyl ofs0) -> + Zmax 0 (ofs + typesize ty) <= size_arguments_vararg tyl ofs0. +Proof. + induction tyl; simpl; intros. + elim H. + destruct a. +- (* int *) + destruct H. + destruct (zlt ofs0 0); inv H. apply size_arguments_vararg_above. + eauto. +- (* float *) + destruct H. + destruct (zlt (align ofs0 2) 0); inv H. apply size_arguments_vararg_above. + eauto. +- (* long *) + destruct H. + destruct (zlt (align ofs0 2) 0); inv H. + rewrite <- Zplus_assoc. simpl. apply size_arguments_vararg_above. + destruct H. + destruct (zlt (align ofs0 2) 0); inv H. + eapply Zle_trans. 2: apply size_arguments_vararg_above. simpl; xomega. + eauto. +- (* float *) + destruct H. + destruct (zlt ofs0 0); inv H. apply size_arguments_vararg_above. + eauto. +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. + unfold loc_arguments, size_arguments; intros. + destruct (cc_vararg (sig_cc s)). + eapply Zle_trans. 2: eapply loc_arguments_vararg_bounded; eauto. xomega. + eapply loc_arguments_rec_bounded; eauto. +Qed. diff --git a/arm/hardfloat/Stacklayout.v b/arm/hardfloat/Stacklayout.v new file mode 100644 index 0000000..7694dcf --- /dev/null +++ b/arm/hardfloat/Stacklayout.v @@ -0,0 +1,132 @@ +(* *********************************************************************) +(* *) +(* 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. *) +(* *) +(* *********************************************************************) + +(** Machine- and ABI-dependent layout information for activation records. *) + +Require Import Coqlib. +Require Import Bounds. + +(** The general shape of activation records is as follows, + from bottom (lowest offsets) to top: +- Space for outgoing arguments to function calls. +- Local stack slots. +- Saved values of integer callee-save registers used by the function. +- Saved values of float callee-save registers used by the function. +- Saved return address into caller. +- Pointer to activation record of the caller. +- Space for the stack-allocated data declared in Cminor. + +The [frame_env] compilation environment records the positions of +the boundaries between areas in the frame part. +*) + +Definition fe_ofs_arg := 0. + +Record frame_env : Type := mk_frame_env { + fe_size: Z; + fe_ofs_link: Z; + fe_ofs_retaddr: Z; + fe_ofs_local: Z; + fe_ofs_int_callee_save: Z; + fe_num_int_callee_save: Z; + fe_ofs_float_callee_save: Z; + fe_num_float_callee_save: Z; + fe_stack_data: Z +}. + +(** Computation of the frame environment from the bounds of the current + function. *) + +Definition make_env (b: bounds) := + let ol := align (4 * b.(bound_outgoing)) 8 in (* locals *) + let oics := ol + 4 * b.(bound_local) in (* integer callee-saves *) + let oendi := oics + 4 * b.(bound_int_callee_save) in + let ofcs := align oendi 8 in (* float callee-saves *) + let ora := ofcs + 8 * b.(bound_float_callee_save) in (* retaddr *) + let olink := ora + 4 in (* back link *) + let ostkdata := olink + 4 in (* stack data *) + let sz := align (ostkdata + b.(bound_stack_data)) 8 in + mk_frame_env sz olink ora ol + oics b.(bound_int_callee_save) + ofcs b.(bound_float_callee_save) + ostkdata. + +(** Separation property *) + +Remark frame_env_separated: + forall b, + let fe := make_env b in + 0 <= fe_ofs_arg + /\ fe_ofs_arg + 4 * b.(bound_outgoing) <= fe.(fe_ofs_local) + /\ fe.(fe_ofs_local) + 4 * b.(bound_local) <= fe.(fe_ofs_int_callee_save) + /\ fe.(fe_ofs_int_callee_save) + 4 * b.(bound_int_callee_save) <= fe.(fe_ofs_float_callee_save) + /\ fe.(fe_ofs_float_callee_save) + 8 * b.(bound_float_callee_save) <= fe.(fe_ofs_retaddr) + /\ fe.(fe_ofs_retaddr) + 4 <= fe.(fe_ofs_link) + /\ fe.(fe_ofs_link) + 4 <= fe.(fe_stack_data) + /\ fe.(fe_stack_data) + b.(bound_stack_data) <= fe.(fe_size). +Proof. + intros. + generalize (align_le (4 * bound_outgoing b) 8 (refl_equal)). + generalize (align_le (fe_ofs_int_callee_save fe + 4 * b.(bound_int_callee_save)) 8 (refl_equal _)). + generalize (align_le (fe_stack_data fe + b.(bound_stack_data)) 8 (refl_equal)). + unfold fe, make_env, fe_size, fe_ofs_link, fe_ofs_retaddr, + fe_ofs_local, fe_ofs_int_callee_save, fe_num_int_callee_save, + fe_ofs_float_callee_save, fe_num_float_callee_save, + fe_stack_data, fe_ofs_arg. + intros. + generalize (bound_local_pos b); intro; + generalize (bound_int_callee_save_pos b); intro; + generalize (bound_float_callee_save_pos b); intro; + generalize (bound_outgoing_pos b); intro; + generalize (bound_stack_data_pos b); intro. + omega. +Qed. + +(** Alignment property *) + +Remark frame_env_aligned: + forall b, + let fe := make_env b in + (4 | fe.(fe_ofs_link)) + /\ (8 | fe.(fe_ofs_local)) + /\ (4 | fe.(fe_ofs_int_callee_save)) + /\ (8 | fe.(fe_ofs_float_callee_save)) + /\ (4 | fe.(fe_ofs_retaddr)) + /\ (8 | fe.(fe_stack_data)) + /\ (8 | fe.(fe_size)). +Proof. + intros. + unfold fe, make_env, fe_size, fe_ofs_link, fe_ofs_retaddr, + fe_ofs_local, fe_ofs_int_callee_save, fe_num_int_callee_save, + fe_ofs_float_callee_save, fe_num_float_callee_save, + fe_stack_data. + set (x1 := 4 * bound_outgoing b). + assert (4 | x1). unfold x1; exists (bound_outgoing b); ring. + set (x2 := align x1 8). + assert (8 | x2). apply align_divides. omega. + set (x3 := x2 + 4 * bound_local b). + assert (4 | x3). apply Zdivide_plus_r. apply Zdivides_trans with 8; auto. exists 2; auto. + exists (bound_local b); ring. + set (x4 := align (x3 + 4 * bound_int_callee_save b) 8). + assert (8 | x4). apply align_divides. omega. + set (x5 := x4 + 8 * bound_float_callee_save b). + assert (8 | x5). apply Zdivide_plus_r; auto. exists (bound_float_callee_save b); ring. + assert (4 | x5). apply Zdivides_trans with 8; auto. exists 2; auto. + set (x6 := x5 + 4). + assert (4 | x6). apply Zdivide_plus_r; auto. exists 1; auto. + set (x7 := x6 + 4). + assert (8 | x7). unfold x7, x6. replace (x5 + 4 + 4) with (x5 + 8) by omega. + apply Zdivide_plus_r; auto. exists 1; auto. + set (x8 := align (x7 + bound_stack_data b) 8). + assert (8 | x8). apply align_divides. omega. + tauto. +Qed. -- cgit v1.2.3