(* *********************************************************************) (* *) (* 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. *) (* *) (* *********************************************************************) (** Operators and addressing modes. The abstract syntax and dynamic semantics for the CminorSel, RTL, LTL and Mach languages depend on the following types, defined in this library: - [condition]: boolean conditions for conditional branches; - [operation]: arithmetic and logical operations; - [addressing]: addressing modes for load and store operations. These types are IA32-specific and correspond roughly to what the processor can compute in one instruction. In other terms, these types reflect the state of the program after instruction selection. For a processor-independent set of operations, see the abstract syntax and dynamic semantics of the Cminor language. *) Require Import Coqlib. Require Import AST. Require Import Integers. Require Import Floats. Require Import Values. Require Import Memory. Require Import Globalenvs. Require Import Events. Set Implicit Arguments. (** Conditions (boolean-valued operators). *) Inductive condition : Type := | Ccomp: comparison -> condition (**r signed integer comparison *) | Ccompu: comparison -> condition (**r unsigned integer comparison *) | Ccompimm: comparison -> int -> condition (**r signed integer comparison with a constant *) | Ccompuimm: comparison -> int -> condition (**r unsigned integer comparison with a constant *) | Ccompf: comparison -> condition (**r 64-bit floating-point comparison *) | Cnotcompf: comparison -> condition (**r negation of a floating-point comparison *) | Ccompfs: comparison -> condition (**r 32-bit floating-point comparison *) | Cnotcompfs: comparison -> condition (**r negation of a floating-point comparison *) | Cmaskzero: int -> condition (**r test [(arg & constant) == 0] *) | Cmasknotzero: int -> condition. (**r test [(arg & constant) != 0] *) (** Addressing modes. [r1], [r2], etc, are the arguments to the addressing. *) Inductive addressing: Type := | Aindexed: int -> addressing (**r Address is [r1 + offset] *) | Aindexed2: int -> addressing (**r Address is [r1 + r2 + offset] *) | Ascaled: int -> int -> addressing (**r Address is [r1 * scale + offset] *) | Aindexed2scaled: int -> int -> addressing (**r Address is [r1 + r2 * scale + offset] *) | Aglobal: ident -> int -> addressing (**r Address is [symbol + offset] *) | Abased: ident -> int -> addressing (**r Address is [symbol + offset + r1] *) | Abasedscaled: int -> ident -> int -> addressing (**r Address is [symbol + offset + r1 * scale] *) | Ainstack: int -> addressing. (**r Address is [stack_pointer + offset] *) (** Arithmetic and logical operations. In the descriptions, [rd] is the result of the operation and [r1], [r2], etc, are the arguments. *) Inductive operation : Type := | Omove: operation (**r [rd = r1] *) | Ointconst: int -> operation (**r [rd] is set to the given integer constant *) | Ofloatconst: float -> operation (**r [rd] is set to the given float constant *) | Osingleconst: float32 -> operation (**r [rd] is set to the given float constant *) | Oindirectsymbol: ident -> operation (**r [rd] is set to the address of the symbol *) (*c Integer arithmetic: *) | Ocast8signed: operation (**r [rd] is 8-bit sign extension of [r1] *) | Ocast8unsigned: operation (**r [rd] is 8-bit zero extension of [r1] *) | Ocast16signed: operation (**r [rd] is 16-bit sign extension of [r1] *) | Ocast16unsigned: operation (**r [rd] is 16-bit zero extension of [r1] *) | Oneg: operation (**r [rd = - r1] *) | Osub: operation (**r [rd = r1 - r2] *) | Omul: operation (**r [rd = r1 * r2] *) | Omulimm: int -> operation (**r [rd = r1 * n] *) | Omulhs: operation (**r [rd = high part of r1 * r2, signed] *) | Omulhu: operation (**r [rd = high part of r1 * r2, unsigned] *) | Odiv: operation (**r [rd = r1 / r2] (signed) *) | Odivu: operation (**r [rd = r1 / r2] (unsigned) *) | Omod: operation (**r [rd = r1 % r2] (signed) *) | Omodu: operation (**r [rd = r1 % r2] (unsigned) *) | Oand: operation (**r [rd = r1 & r2] *) | Oandimm: int -> operation (**r [rd = r1 & n] *) | Oor: operation (**r [rd = r1 | r2] *) | Oorimm: int -> operation (**r [rd = r1 | n] *) | Oxor: operation (**r [rd = r1 ^ r2] *) | Oxorimm: int -> operation (**r [rd = r1 ^ n] *) | Onot: operation (**r [rd = ~r1] *) | Oshl: operation (**r [rd = r1 << r2] *) | Oshlimm: int -> operation (**r [rd = r1 << n] *) | Oshr: operation (**r [rd = r1 >> r2] (signed) *) | Oshrimm: int -> operation (**r [rd = r1 >> n] (signed) *) | Oshrximm: int -> operation (**r [rd = r1 / 2^n] (signed) *) | Oshru: operation (**r [rd = r1 >> r2] (unsigned) *) | Oshruimm: int -> operation (**r [rd = r1 >> n] (unsigned) *) | Ororimm: int -> operation (**r rotate right immediate *) | Oshldimm: int -> operation (**r [rd = r1 << n | r2 >> (32-n)] *) | Olea: addressing -> operation (**r effective address *) (*c Floating-point arithmetic: *) | Onegf: operation (**r [rd = - r1] *) | Oabsf: operation (**r [rd = abs(r1)] *) | Oaddf: operation (**r [rd = r1 + r2] *) | Osubf: operation (**r [rd = r1 - r2] *) | Omulf: operation (**r [rd = r1 * r2] *) | Odivf: operation (**r [rd = r1 / r2] *) | Onegfs: operation (**r [rd = - r1] *) | Oabsfs: operation (**r [rd = abs(r1)] *) | Oaddfs: operation (**r [rd = r1 + r2] *) | Osubfs: operation (**r [rd = r1 - r2] *) | Omulfs: operation (**r [rd = r1 * r2] *) | Odivfs: operation (**r [rd = r1 / r2] *) | Osingleoffloat: operation (**r [rd] is [r1] truncated to single-precision float *) | Ofloatofsingle: operation (**r [rd] is [r1] extended to double-precision float *) (*c Conversions between int and float: *) | Ointoffloat: operation (**r [rd = signed_int_of_float64(r1)] *) | Ofloatofint: operation (**r [rd = float64_of_signed_int(r1)] *) | Ointofsingle: operation (**r [rd = signed_int_of_float32(r1)] *) | Osingleofint: operation (**r [rd = float32_of_signed_int(r1)] *) (*c Manipulating 64-bit integers: *) | Omakelong: operation (**r [rd = r1 << 32 | r2] *) | Olowlong: operation (**r [rd = low-word(r1)] *) | Ohighlong: operation (**r [rd = high-word(r1)] *) (*c Boolean tests: *) | Ocmp: condition -> operation. (**r [rd = 1] if condition holds, [rd = 0] otherwise. *) (** Derived operators. *) Definition Oaddrsymbol (id: ident) (ofs: int) : operation := Olea (Aglobal id ofs). Definition Oaddrstack (ofs: int) : operation := Olea (Ainstack ofs). Definition Oaddimm (n: int) : operation := Olea (Aindexed n). (** Comparison functions (used in modules [CSE] and [Allocation]). *) Definition eq_condition (x y: condition) : {x=y} + {x<>y}. Proof. generalize Int.eq_dec; intro. assert (forall (x y: comparison), {x=y}+{x<>y}). decide equality. decide equality. Defined. Definition eq_addressing (x y: addressing) : {x=y} + {x<>y}. Proof. generalize Int.eq_dec; intro. assert (forall (x y: ident), {x=y}+{x<>y}). exact peq. decide equality. Defined. Definition eq_operation (x y: operation): {x=y} + {x<>y}. Proof. generalize Int.eq_dec; intro. generalize Float.eq_dec; intro. generalize Float32.eq_dec; intro. generalize Int64.eq_dec; intro. decide equality. apply peq. apply eq_addressing. apply eq_condition. Defined. Global Opaque eq_condition eq_addressing eq_operation. (** * Evaluation functions *) (** Evaluation of conditions, operators and addressing modes applied to lists of values. Return [None] when the computation can trigger an error, e.g. integer division by zero. [eval_condition] returns a boolean, [eval_operation] and [eval_addressing] return a value. *) Definition eval_condition (cond: condition) (vl: list val) (m: mem): option bool := match cond, vl with | Ccomp c, v1 :: v2 :: nil => Val.cmp_bool c v1 v2 | Ccompu c, v1 :: v2 :: nil => Val.cmpu_bool (Mem.valid_pointer m) c v1 v2 | Ccompimm c n, v1 :: nil => Val.cmp_bool c v1 (Vint n) | Ccompuimm c n, v1 :: nil => Val.cmpu_bool (Mem.valid_pointer m) c v1 (Vint n) | Ccompf c, v1 :: v2 :: nil => Val.cmpf_bool c v1 v2 | Cnotcompf c, v1 :: v2 :: nil => option_map negb (Val.cmpf_bool c v1 v2) | Ccompfs c, v1 :: v2 :: nil => Val.cmpfs_bool c v1 v2 | Cnotcompfs c, v1 :: v2 :: nil => option_map negb (Val.cmpfs_bool c v1 v2) | Cmaskzero n, v1 :: nil => Val.maskzero_bool v1 n | Cmasknotzero n, v1 :: nil => option_map negb (Val.maskzero_bool v1 n) | _, _ => None end. Definition eval_addressing (F V: Type) (genv: Genv.t F V) (sp: val) (addr: addressing) (vl: list val) : option val := match addr, vl with | Aindexed n, v1::nil => Some (Val.add v1 (Vint n)) | Aindexed2 n, v1::v2::nil => Some (Val.add (Val.add v1 v2) (Vint n)) | Ascaled sc ofs, v1::nil => Some (Val.add (Val.mul v1 (Vint sc)) (Vint ofs)) | Aindexed2scaled sc ofs, v1::v2::nil => Some(Val.add v1 (Val.add (Val.mul v2 (Vint sc)) (Vint ofs))) | Aglobal s ofs, nil => Some (Genv.symbol_address genv s ofs) | Abased s ofs, v1::nil => Some (Val.add (Genv.symbol_address genv s ofs) v1) | Abasedscaled sc s ofs, v1::nil => Some (Val.add (Genv.symbol_address genv s ofs) (Val.mul v1 (Vint sc))) | Ainstack ofs, nil => Some(Val.add sp (Vint ofs)) | _, _ => None end. Definition eval_operation (F V: Type) (genv: Genv.t F V) (sp: val) (op: operation) (vl: list val) (m: mem): option val := match op, vl with | Omove, v1::nil => Some v1 | Ointconst n, nil => Some (Vint n) | Ofloatconst n, nil => Some (Vfloat n) | Osingleconst n, nil => Some (Vsingle n) | Oindirectsymbol id, nil => Some (Genv.symbol_address genv id Int.zero) | Ocast8signed, v1 :: nil => Some (Val.sign_ext 8 v1) | Ocast8unsigned, v1 :: nil => Some (Val.zero_ext 8 v1) | Ocast16signed, v1 :: nil => Some (Val.sign_ext 16 v1) | Ocast16unsigned, v1 :: nil => Some (Val.zero_ext 16 v1) | Oneg, v1::nil => Some (Val.neg v1) | Osub, v1::v2::nil => Some (Val.sub v1 v2) | Omul, v1::v2::nil => Some (Val.mul v1 v2) | Omulimm n, v1::nil => Some (Val.mul v1 (Vint n)) | Omulhs, v1::v2::nil => Some (Val.mulhs v1 v2) | Omulhu, v1::v2::nil => Some (Val.mulhu v1 v2) | Odiv, v1::v2::nil => Val.divs v1 v2 | Odivu, v1::v2::nil => Val.divu v1 v2 | Omod, v1::v2::nil => Val.mods v1 v2 | Omodu, v1::v2::nil => Val.modu v1 v2 | Oand, v1::v2::nil => Some(Val.and v1 v2) | Oandimm n, v1::nil => Some (Val.and v1 (Vint n)) | Oor, v1::v2::nil => Some(Val.or v1 v2) | Oorimm n, v1::nil => Some (Val.or v1 (Vint n)) | Oxor, v1::v2::nil => Some(Val.xor v1 v2) | Oxorimm n, v1::nil => Some (Val.xor v1 (Vint n)) | Onot, v1::nil => Some(Val.notint v1) | Oshl, v1::v2::nil => Some (Val.shl v1 v2) | Oshlimm n, v1::nil => Some (Val.shl v1 (Vint n)) | Oshr, v1::v2::nil => Some (Val.shr v1 v2) | Oshrimm n, v1::nil => Some (Val.shr v1 (Vint n)) | Oshrximm n, v1::nil => Val.shrx v1 (Vint n) | Oshru, v1::v2::nil => Some (Val.shru v1 v2) | Oshruimm n, v1::nil => Some (Val.shru v1 (Vint n)) | Ororimm n, v1::nil => Some (Val.ror v1 (Vint n)) | Oshldimm n, v1::v2::nil => Some (Val.or (Val.shl v1 (Vint n)) (Val.shru v2 (Vint (Int.sub Int.iwordsize n)))) | Olea addr, _ => eval_addressing genv sp addr vl | Onegf, v1::nil => Some(Val.negf v1) | Oabsf, v1::nil => Some(Val.absf v1) | Oaddf, v1::v2::nil => Some(Val.addf v1 v2) | Osubf, v1::v2::nil => Some(Val.subf v1 v2) | Omulf, v1::v2::nil => Some(Val.mulf v1 v2) | Odivf, v1::v2::nil => Some(Val.divf v1 v2) | Onegfs, v1::nil => Some(Val.negfs v1) | Oabsfs, v1::nil => Some(Val.absfs v1) | Oaddfs, v1::v2::nil => Some(Val.addfs v1 v2) | Osubfs, v1::v2::nil => Some(Val.subfs v1 v2) | Omulfs, v1::v2::nil => Some(Val.mulfs v1 v2) | Odivfs, v1::v2::nil => Some(Val.divfs v1 v2) | Osingleoffloat, v1::nil => Some(Val.singleoffloat v1) | Ofloatofsingle, v1::nil => Some(Val.floatofsingle v1) | Ointoffloat, v1::nil => Val.intoffloat v1 | Ofloatofint, v1::nil => Val.floatofint v1 | Ointofsingle, v1::nil => Val.intofsingle v1 | Osingleofint, v1::nil => Val.singleofint v1 | Omakelong, v1::v2::nil => Some(Val.longofwords v1 v2) | Olowlong, v1::nil => Some(Val.loword v1) | Ohighlong, v1::nil => Some(Val.hiword v1) | Ocmp c, _ => Some(Val.of_optbool (eval_condition c vl m)) | _, _ => None end. Ltac FuncInv := match goal with | H: (match ?x with nil => _ | _ :: _ => _ end = Some _) |- _ => destruct x; simpl in H; try discriminate; FuncInv | H: (match ?v with Vundef => _ | Vint _ => _ | Vfloat _ => _ | Vptr _ _ => _ end = Some _) |- _ => destruct v; simpl in H; try discriminate; FuncInv | H: (Some _ = Some _) |- _ => injection H; intros; clear H; FuncInv | _ => idtac end. (** * Static typing of conditions, operators and addressing modes. *) Definition type_of_condition (c: condition) : list typ := match c with | Ccomp _ => Tint :: Tint :: nil | Ccompu _ => Tint :: Tint :: nil | Ccompimm _ _ => Tint :: nil | Ccompuimm _ _ => Tint :: nil | Ccompf _ => Tfloat :: Tfloat :: nil | Cnotcompf _ => Tfloat :: Tfloat :: nil | Ccompfs _ => Tsingle :: Tsingle :: nil | Cnotcompfs _ => Tsingle :: Tsingle :: nil | Cmaskzero _ => Tint :: nil | Cmasknotzero _ => Tint :: nil end. Definition type_of_addressing (addr: addressing) : list typ := match addr with | Aindexed _ => Tint :: nil | Aindexed2 _ => Tint :: Tint :: nil | Ascaled _ _ => Tint :: nil | Aindexed2scaled _ _ => Tint :: Tint :: nil | Aglobal _ _ => nil | Abased _ _ => Tint :: nil | Abasedscaled _ _ _ => Tint :: nil | Ainstack _ => nil end. Definition type_of_operation (op: operation) : list typ * typ := match op with | Omove => (nil, Tint) (* treated specially *) | Ointconst _ => (nil, Tint) | Ofloatconst f => (nil, Tfloat) | Osingleconst f => (nil, Tsingle) | Oindirectsymbol _ => (nil, Tint) | Ocast8signed => (Tint :: nil, Tint) | Ocast8unsigned => (Tint :: nil, Tint) | Ocast16signed => (Tint :: nil, Tint) | Ocast16unsigned => (Tint :: nil, Tint) | Oneg => (Tint :: nil, Tint) | Osub => (Tint :: Tint :: nil, Tint) | Omul => (Tint :: Tint :: nil, Tint) | Omulimm _ => (Tint :: nil, Tint) | Omulhs => (Tint :: Tint :: nil, Tint) | Omulhu => (Tint :: Tint :: nil, Tint) | Odiv => (Tint :: Tint :: nil, Tint) | Odivu => (Tint :: Tint :: nil, Tint) | Omod => (Tint :: Tint :: nil, Tint) | Omodu => (Tint :: Tint :: nil, Tint) | Oand => (Tint :: Tint :: nil, Tint) | Oandimm _ => (Tint :: nil, Tint) | Oor => (Tint :: Tint :: nil, Tint) | Oorimm _ => (Tint :: nil, Tint) | Oxor => (Tint :: Tint :: nil, Tint) | Oxorimm _ => (Tint :: nil, Tint) | Onot => (Tint :: nil, Tint) | Oshl => (Tint :: Tint :: nil, Tint) | Oshlimm _ => (Tint :: nil, Tint) | Oshr => (Tint :: Tint :: nil, Tint) | Oshrimm _ => (Tint :: nil, Tint) | Oshrximm _ => (Tint :: nil, Tint) | Oshru => (Tint :: Tint :: nil, Tint) | Oshruimm _ => (Tint :: nil, Tint) | Ororimm _ => (Tint :: nil, Tint) | Oshldimm _ => (Tint :: Tint :: nil, Tint) | Olea addr => (type_of_addressing addr, Tint) | Onegf => (Tfloat :: nil, Tfloat) | Oabsf => (Tfloat :: nil, Tfloat) | Oaddf => (Tfloat :: Tfloat :: nil, Tfloat) | Osubf => (Tfloat :: Tfloat :: nil, Tfloat) | Omulf => (Tfloat :: Tfloat :: nil, Tfloat) | Odivf => (Tfloat :: Tfloat :: nil, Tfloat) | Onegfs => (Tsingle :: nil, Tsingle) | Oabsfs => (Tsingle :: nil, Tsingle) | Oaddfs => (Tsingle :: Tsingle :: nil, Tsingle) | Osubfs => (Tsingle :: Tsingle :: nil, Tsingle) | Omulfs => (Tsingle :: Tsingle :: nil, Tsingle) | Odivfs => (Tsingle :: Tsingle :: nil, Tsingle) | Osingleoffloat => (Tfloat :: nil, Tsingle) | Ofloatofsingle => (Tsingle :: nil, Tfloat) | Ointoffloat => (Tfloat :: nil, Tint) | Ofloatofint => (Tint :: nil, Tfloat) | Ointofsingle => (Tsingle :: nil, Tint) | Osingleofint => (Tint :: nil, Tsingle) | Omakelong => (Tint :: Tint :: nil, Tlong) | Olowlong => (Tlong :: nil, Tint) | Ohighlong => (Tlong :: nil, Tint) | Ocmp c => (type_of_condition c, Tint) end. (** Weak type soundness results for [eval_operation]: the result values, when defined, are always of the type predicted by [type_of_operation]. *) Section SOUNDNESS. Variable A V: Type. Variable genv: Genv.t A V. Lemma type_of_addressing_sound: forall addr vl sp v, eval_addressing genv sp addr vl = Some v -> Val.has_type v Tint. Proof with (try exact I). intros. destruct addr; simpl in H; FuncInv; subst; simpl. destruct v0... destruct v0... destruct v1... destruct v1... destruct v0... destruct v0... destruct v1... destruct v1... unfold Genv.symbol_address; destruct (Genv.find_symbol genv i)... unfold Genv.symbol_address; destruct (Genv.find_symbol genv i)... unfold Genv.symbol_address; destruct (Genv.find_symbol genv i)... destruct v0... destruct v0... unfold Genv.symbol_address; destruct (Genv.find_symbol genv i0)... destruct v0... destruct sp... Qed. Lemma type_of_operation_sound: forall op vl sp v m, op <> Omove -> eval_operation genv sp op vl m = Some v -> Val.has_type v (snd (type_of_operation op)). Proof with (try exact I). intros. destruct op; simpl in H0; FuncInv; subst; simpl. congruence. exact I. exact I. exact I. unfold Genv.symbol_address; destruct (Genv.find_symbol genv i)... destruct v0... destruct v0... destruct v0... destruct v0... destruct v0... destruct v0; destruct v1... simpl. destruct (eq_block b b0)... destruct v0; destruct v1... destruct v0... destruct v0; destruct v1... destruct v0; destruct v1... destruct v0; destruct v1; simpl in *; inv H0. destruct (Int.eq i0 Int.zero || Int.eq i (Int.repr Int.min_signed) && Int.eq i0 Int.mone); inv H2... destruct v0; destruct v1; simpl in *; inv H0. destruct (Int.eq i0 Int.zero); inv H2... destruct v0; destruct v1; simpl in *; inv H0. destruct (Int.eq i0 Int.zero || Int.eq i (Int.repr Int.min_signed) && Int.eq i0 Int.mone); inv H2... destruct v0; destruct v1; simpl in *; inv H0. destruct (Int.eq i0 Int.zero); inv H2... destruct v0; destruct v1... destruct v0... destruct v0; destruct v1... destruct v0... destruct v0; destruct v1... destruct v0... destruct v0... destruct v0; destruct v1; simpl... destruct (Int.ltu i0 Int.iwordsize)... destruct v0; simpl... destruct (Int.ltu i Int.iwordsize)... destruct v0; destruct v1; simpl... destruct (Int.ltu i0 Int.iwordsize)... destruct v0; simpl... destruct (Int.ltu i Int.iwordsize)... destruct v0; simpl in H0; try discriminate. destruct (Int.ltu i (Int.repr 31)); inv H0... destruct v0; destruct v1; simpl... destruct (Int.ltu i0 Int.iwordsize)... destruct v0; simpl... destruct (Int.ltu i Int.iwordsize)... destruct v0; simpl... destruct (Int.ltu i Int.iwordsize)... destruct v0; simpl... destruct (Int.ltu i Int.iwordsize)... destruct v1; simpl... destruct (Int.ltu (Int.sub Int.iwordsize i) Int.iwordsize)... eapply type_of_addressing_sound; eauto. destruct v0... destruct v0... destruct v0; destruct v1... destruct v0; destruct v1... destruct v0; destruct v1... destruct v0; destruct v1... destruct v0... destruct v0... destruct v0; destruct v1... destruct v0; destruct v1... destruct v0; destruct v1... destruct v0; destruct v1... destruct v0... destruct v0... destruct v0; simpl in H0; inv H0. destruct (Float.to_int f); inv H2... destruct v0; simpl in H0; inv H0... destruct v0; simpl in H0; inv H0. destruct (Float32.to_int f); inv H2... destruct v0; simpl in H0; inv H0... destruct v0; destruct v1... destruct v0... destruct v0... destruct (eval_condition c vl m); simpl... destruct b... Qed. End SOUNDNESS. (** * Manipulating and transforming operations *) (** Recognition of move operations. *) Definition is_move_operation (A: Type) (op: operation) (args: list A) : option A := match op, args with | Omove, arg :: nil => Some arg | _, _ => None end. Lemma is_move_operation_correct: forall (A: Type) (op: operation) (args: list A) (a: A), is_move_operation op args = Some a -> op = Omove /\ args = a :: nil. Proof. intros until a. unfold is_move_operation; destruct op; try (intros; discriminate). destruct args. intros; discriminate. destruct args. intros. intuition congruence. intros; discriminate. Qed. (** [negate_condition cond] returns a condition that is logically equivalent to the negation of [cond]. *) Definition negate_condition (cond: condition): condition := match cond with | Ccomp c => Ccomp(negate_comparison c) | Ccompu c => Ccompu(negate_comparison c) | Ccompimm c n => Ccompimm (negate_comparison c) n | Ccompuimm c n => Ccompuimm (negate_comparison c) n | Ccompf c => Cnotcompf c | Cnotcompf c => Ccompf c | Ccompfs c => Cnotcompfs c | Cnotcompfs c => Ccompfs c | Cmaskzero n => Cmasknotzero n | Cmasknotzero n => Cmaskzero n end. Lemma eval_negate_condition: forall cond vl m, eval_condition (negate_condition cond) vl m = option_map negb (eval_condition cond vl m). Proof. intros. destruct cond; simpl. repeat (destruct vl; auto). apply Val.negate_cmp_bool. repeat (destruct vl; auto). apply Val.negate_cmpu_bool. repeat (destruct vl; auto). apply Val.negate_cmp_bool. repeat (destruct vl; auto). apply Val.negate_cmpu_bool. repeat (destruct vl; auto). repeat (destruct vl; auto). destruct (Val.cmpf_bool c v v0) as [[]|]; auto. repeat (destruct vl; auto). repeat (destruct vl; auto). destruct (Val.cmpfs_bool c v v0) as [[]|]; auto. destruct vl; auto. destruct vl; auto. destruct vl; auto. destruct vl; auto. destruct (Val.maskzero_bool v i) as [[]|]; auto. Qed. (** Shifting stack-relative references. This is used in [Stacking]. *) Definition shift_stack_addressing (delta: int) (addr: addressing) := match addr with | Ainstack ofs => Ainstack (Int.add delta ofs) | _ => addr end. Definition shift_stack_operation (delta: int) (op: operation) := match op with | Olea addr => Olea (shift_stack_addressing delta addr) | _ => op end. Lemma type_shift_stack_addressing: forall delta addr, type_of_addressing (shift_stack_addressing delta addr) = type_of_addressing addr. Proof. intros. destruct addr; auto. Qed. Lemma type_shift_stack_operation: forall delta op, type_of_operation (shift_stack_operation delta op) = type_of_operation op. Proof. intros. destruct op; auto. simpl. decEq. apply type_shift_stack_addressing. Qed. Lemma eval_shift_stack_addressing: forall F V (ge: Genv.t F V) sp addr vl delta, eval_addressing ge sp (shift_stack_addressing delta addr) vl = eval_addressing ge (Val.add sp (Vint delta)) addr vl. Proof. intros. destruct addr; simpl; auto. rewrite Val.add_assoc. simpl. auto. Qed. Lemma eval_shift_stack_operation: forall F V (ge: Genv.t F V) sp op vl m delta, eval_operation ge sp (shift_stack_operation delta op) vl m = eval_operation ge (Val.add sp (Vint delta)) op vl m. Proof. intros. destruct op; simpl; auto. apply eval_shift_stack_addressing. Qed. (** Offset an addressing mode [addr] by a quantity [delta], so that it designates the pointer [delta] bytes past the pointer designated by [addr]. On PowerPC and ARM, this may be undefined, in which case [None] is returned. On IA32, it is always defined, but we keep the same interface. *) Definition offset_addressing_total (addr: addressing) (delta: int) : addressing := match addr with | Aindexed n => Aindexed (Int.add n delta) | Aindexed2 n => Aindexed2 (Int.add n delta) | Ascaled sc n => Ascaled sc (Int.add n delta) | Aindexed2scaled sc n => Aindexed2scaled sc (Int.add n delta) | Aglobal s n => Aglobal s (Int.add n delta) | Abased s n => Abased s (Int.add n delta) | Abasedscaled sc s n => Abasedscaled sc s (Int.add n delta) | Ainstack n => Ainstack (Int.add n delta) end. Definition offset_addressing (addr: addressing) (delta: int) : option addressing := Some(offset_addressing_total addr delta). Lemma eval_offset_addressing_total: forall (F V: Type) (ge: Genv.t F V) sp addr args delta v, eval_addressing ge sp addr args = Some v -> eval_addressing ge sp (offset_addressing_total addr delta) args = Some(Val.add v (Vint delta)). Proof. intros. destruct addr; simpl in *; FuncInv; subst. rewrite Val.add_assoc; auto. rewrite !Val.add_assoc; auto. rewrite !Val.add_assoc; auto. rewrite !Val.add_assoc; auto. unfold Genv.symbol_address. destruct (Genv.find_symbol ge i); auto. unfold Genv.symbol_address. destruct (Genv.find_symbol ge i); auto. rewrite Val.add_assoc. rewrite Val.add_permut. rewrite Val.add_commut. auto. unfold Genv.symbol_address. destruct (Genv.find_symbol ge i0); auto. rewrite Val.add_assoc. rewrite Val.add_permut. rewrite Val.add_commut. auto. rewrite Val.add_assoc. auto. Qed. Lemma eval_offset_addressing: forall (F V: Type) (ge: Genv.t F V) sp addr args delta addr' v, offset_addressing addr delta = Some addr' -> eval_addressing ge sp addr args = Some v -> eval_addressing ge sp addr' args = Some(Val.add v (Vint delta)). Proof. intros. unfold offset_addressing in H; inv H. eapply eval_offset_addressing_total; eauto. Qed. (** Operations that are so cheap to recompute that CSE should not factor them out. *) Definition is_trivial_op (op: operation) : bool := match op with | Omove => true | Ointconst _ => true | Olea (Aglobal _ _) => true | Olea (Ainstack _) => true | _ => false end. (** Operations that depend on the memory state. *) Definition op_depends_on_memory (op: operation) : bool := match op with | Ocmp (Ccompu _) => true | _ => false end. Lemma op_depends_on_memory_correct: forall (F V: Type) (ge: Genv.t F V) sp op args m1 m2, op_depends_on_memory op = false -> eval_operation ge sp op args m1 = eval_operation ge sp op args m2. Proof. intros until m2. destruct op; simpl; try congruence. destruct c; simpl; try congruence. reflexivity. Qed. (** * Invariance and compatibility properties. *) (** [eval_operation] and [eval_addressing] depend on a global environment for resolving references to global symbols. We show that they give the same results if a global environment is replaced by another that assigns the same addresses to the same symbols. *) Section GENV_TRANSF. Variable F1 F2 V1 V2: Type. Variable ge1: Genv.t F1 V1. Variable ge2: Genv.t F2 V2. Hypothesis agree_on_symbols: forall (s: ident), Genv.find_symbol ge2 s = Genv.find_symbol ge1 s. Lemma eval_addressing_preserved: forall sp addr vl, eval_addressing ge2 sp addr vl = eval_addressing ge1 sp addr vl. Proof. intros. unfold eval_addressing, Genv.symbol_address; destruct addr; try rewrite agree_on_symbols; reflexivity. Qed. Lemma eval_operation_preserved: forall sp op vl m, eval_operation ge2 sp op vl m = eval_operation ge1 sp op vl m. Proof. intros. unfold eval_operation; destruct op; auto. unfold Genv.symbol_address. rewrite agree_on_symbols. auto. apply eval_addressing_preserved. Qed. End GENV_TRANSF. (** Compatibility of the evaluation functions with value injections. *) Section EVAL_COMPAT. Variable F V: Type. Variable genv: Genv.t F V. Variable f: meminj. Hypothesis symbol_address_inj: forall id ofs, val_inject f (Genv.symbol_address genv id ofs) (Genv.symbol_address genv id ofs). Variable m1: mem. Variable m2: mem. Hypothesis valid_pointer_inj: forall b1 ofs b2 delta, f b1 = Some(b2, delta) -> Mem.valid_pointer m1 b1 (Int.unsigned ofs) = true -> Mem.valid_pointer m2 b2 (Int.unsigned (Int.add ofs (Int.repr delta))) = true. Hypothesis weak_valid_pointer_inj: forall b1 ofs b2 delta, f b1 = Some(b2, delta) -> Mem.weak_valid_pointer m1 b1 (Int.unsigned ofs) = true -> Mem.weak_valid_pointer m2 b2 (Int.unsigned (Int.add ofs (Int.repr delta))) = true. Hypothesis weak_valid_pointer_no_overflow: forall b1 ofs b2 delta, f b1 = Some(b2, delta) -> Mem.weak_valid_pointer m1 b1 (Int.unsigned ofs) = true -> 0 <= Int.unsigned ofs + Int.unsigned (Int.repr delta) <= Int.max_unsigned. Hypothesis valid_different_pointers_inj: forall b1 ofs1 b2 ofs2 b1' delta1 b2' delta2, b1 <> b2 -> Mem.valid_pointer m1 b1 (Int.unsigned ofs1) = true -> Mem.valid_pointer m1 b2 (Int.unsigned ofs2) = true -> f b1 = Some (b1', delta1) -> f b2 = Some (b2', delta2) -> b1' <> b2' \/ Int.unsigned (Int.add ofs1 (Int.repr delta1)) <> Int.unsigned (Int.add ofs2 (Int.repr delta2)). Ltac InvInject := match goal with | [ H: val_inject _ (Vint _) _ |- _ ] => inv H; InvInject | [ H: val_inject _ (Vfloat _) _ |- _ ] => inv H; InvInject | [ H: val_inject _ (Vptr _ _) _ |- _ ] => inv H; InvInject | [ H: val_list_inject _ nil _ |- _ ] => inv H; InvInject | [ H: val_list_inject _ (_ :: _) _ |- _ ] => inv H; InvInject | _ => idtac end. Lemma eval_condition_inj: forall cond vl1 vl2 b, val_list_inject f vl1 vl2 -> eval_condition cond vl1 m1 = Some b -> eval_condition cond vl2 m2 = Some b. Proof. intros. destruct cond; simpl in H0; FuncInv; InvInject; simpl; auto. inv H3; inv H2; simpl in H0; inv H0; auto. eauto 3 using val_cmpu_bool_inject, Mem.valid_pointer_implies. inv H3; simpl in H0; inv H0; auto. eauto 3 using val_cmpu_bool_inject, Mem.valid_pointer_implies. inv H3; inv H2; simpl in H0; inv H0; auto. inv H3; inv H2; simpl in H0; inv H0; auto. inv H3; inv H2; simpl in H0; inv H0; auto. inv H3; inv H2; simpl in H0; inv H0; auto. inv H3; try discriminate; auto. inv H3; try discriminate; auto. Qed. Ltac TrivialExists := match goal with | [ |- exists v2, Some ?v1 = Some v2 /\ val_inject _ _ v2 ] => exists v1; split; auto | _ => idtac end. Lemma eval_addressing_inj: forall addr sp1 vl1 sp2 vl2 v1, val_inject f sp1 sp2 -> val_list_inject f vl1 vl2 -> eval_addressing genv sp1 addr vl1 = Some v1 -> exists v2, eval_addressing genv sp2 addr vl2 = Some v2 /\ val_inject f v1 v2. Proof. intros. destruct addr; simpl in H1; simpl; FuncInv; InvInject; TrivialExists. apply Values.val_add_inject; auto. apply Values.val_add_inject; auto. apply Values.val_add_inject; auto. apply Values.val_add_inject; auto. inv H4; simpl; auto. apply Values.val_add_inject; auto. apply Values.val_add_inject; auto. inv H2; simpl; auto. apply Values.val_add_inject; auto. apply Values.val_add_inject; auto. inv H4; simpl; auto. apply Values.val_add_inject; auto. Qed. Lemma eval_operation_inj: forall op sp1 vl1 sp2 vl2 v1, val_inject f sp1 sp2 -> val_list_inject f vl1 vl2 -> eval_operation genv sp1 op vl1 m1 = Some v1 -> exists v2, eval_operation genv sp2 op vl2 m2 = Some v2 /\ val_inject f v1 v2. Proof. intros. destruct op; simpl in H1; simpl; FuncInv; InvInject; TrivialExists. inv H4; simpl; auto. inv H4; simpl; auto. inv H4; simpl; auto. inv H4; simpl; auto. inv H4; simpl; auto. inv H4; inv H2; simpl; auto. econstructor; eauto. rewrite Int.sub_add_l. auto. destruct (eq_block b1 b0); auto. subst. rewrite H1 in H0. inv H0. rewrite dec_eq_true. rewrite Int.sub_shifted. auto. inv H4; inv H2; simpl; auto. inv H4; simpl; auto. inv H4; inv H2; simpl; auto. inv H4; inv H2; simpl; auto. inv H4; inv H3; simpl in H1; inv H1. simpl. destruct (Int.eq i0 Int.zero || Int.eq i (Int.repr Int.min_signed) && Int.eq i0 Int.mone); inv H2. TrivialExists. inv H4; inv H3; simpl in H1; inv H1. simpl. destruct (Int.eq i0 Int.zero); inv H2. TrivialExists. inv H4; inv H3; simpl in H1; inv H1. simpl. destruct (Int.eq i0 Int.zero || Int.eq i (Int.repr Int.min_signed) && Int.eq i0 Int.mone); inv H2. TrivialExists. inv H4; inv H3; simpl in H1; inv H1. simpl. destruct (Int.eq i0 Int.zero); inv H2. TrivialExists. inv H4; inv H2; simpl; auto. inv H4; simpl; auto. inv H4; inv H2; simpl; auto. inv H4; simpl; auto. inv H4; inv H2; simpl; auto. inv H4; simpl; auto. inv H4; simpl; auto. inv H4; inv H2; simpl; auto. destruct (Int.ltu i0 Int.iwordsize); auto. inv H4; simpl; auto. destruct (Int.ltu i Int.iwordsize); auto. inv H4; inv H2; simpl; auto. destruct (Int.ltu i0 Int.iwordsize); auto. inv H4; simpl; auto. destruct (Int.ltu i Int.iwordsize); auto. inv H4; simpl in H1; try discriminate. simpl. destruct (Int.ltu i (Int.repr 31)); inv H1. TrivialExists. inv H4; inv H2; simpl; auto. destruct (Int.ltu i0 Int.iwordsize); auto. inv H4; simpl; auto. destruct (Int.ltu i Int.iwordsize); auto. inv H4; simpl; auto. destruct (Int.ltu i Int.iwordsize); auto. inv H4; simpl; auto. destruct (Int.ltu i Int.iwordsize); auto. inv H2; simpl; auto. destruct (Int.ltu (Int.sub Int.iwordsize i) Int.iwordsize); auto. eapply eval_addressing_inj; eauto. inv H4; simpl; auto. inv H4; simpl; auto. inv H4; inv H2; simpl; auto. inv H4; inv H2; simpl; auto. inv H4; inv H2; simpl; auto. inv H4; inv H2; simpl; auto. inv H4; simpl; auto. inv H4; simpl; auto. inv H4; inv H2; simpl; auto. inv H4; inv H2; simpl; auto. inv H4; inv H2; simpl; auto. inv H4; inv H2; simpl; auto. inv H4; simpl; auto. inv H4; simpl; auto. inv H4; simpl in H1; inv H1. simpl. destruct (Float.to_int f0); simpl in H2; inv H2. exists (Vint i); auto. inv H4; simpl in H1; inv H1. simpl. TrivialExists. inv H4; simpl in H1; inv H1. simpl. destruct (Float32.to_int f0); simpl in H2; inv H2. exists (Vint i); auto. inv H4; simpl in H1; inv H1. simpl. TrivialExists. inv H4; inv H2; simpl; auto. inv H4; simpl; auto. inv H4; simpl; auto. subst v1. destruct (eval_condition c vl1 m1) eqn:?. exploit eval_condition_inj; eauto. intros EQ; rewrite EQ. destruct b; simpl; constructor. simpl; constructor. Qed. End EVAL_COMPAT. (** Compatibility of the evaluation functions with the ``is less defined'' relation over values. *) Section EVAL_LESSDEF. Variable F V: Type. Variable genv: Genv.t F V. Remark valid_pointer_extends: forall m1 m2, Mem.extends m1 m2 -> forall b1 ofs b2 delta, Some(b1, 0) = Some(b2, delta) -> Mem.valid_pointer m1 b1 (Int.unsigned ofs) = true -> Mem.valid_pointer m2 b2 (Int.unsigned (Int.add ofs (Int.repr delta))) = true. Proof. intros. inv H0. rewrite Int.add_zero. eapply Mem.valid_pointer_extends; eauto. Qed. Remark weak_valid_pointer_extends: forall m1 m2, Mem.extends m1 m2 -> forall b1 ofs b2 delta, Some(b1, 0) = Some(b2, delta) -> Mem.weak_valid_pointer m1 b1 (Int.unsigned ofs) = true -> Mem.weak_valid_pointer m2 b2 (Int.unsigned (Int.add ofs (Int.repr delta))) = true. Proof. intros. inv H0. rewrite Int.add_zero. eapply Mem.weak_valid_pointer_extends; eauto. Qed. Remark weak_valid_pointer_no_overflow_extends: forall m1 b1 ofs b2 delta, Some(b1, 0) = Some(b2, delta) -> Mem.weak_valid_pointer m1 b1 (Int.unsigned ofs) = true -> 0 <= Int.unsigned ofs + Int.unsigned (Int.repr delta) <= Int.max_unsigned. Proof. intros. inv H. rewrite Zplus_0_r. apply Int.unsigned_range_2. Qed. Remark valid_different_pointers_extends: forall m1 b1 ofs1 b2 ofs2 b1' delta1 b2' delta2, b1 <> b2 -> Mem.valid_pointer m1 b1 (Int.unsigned ofs1) = true -> Mem.valid_pointer m1 b2 (Int.unsigned ofs2) = true -> Some(b1, 0) = Some (b1', delta1) -> Some(b2, 0) = Some (b2', delta2) -> b1' <> b2' \/ Int.unsigned(Int.add ofs1 (Int.repr delta1)) <> Int.unsigned(Int.add ofs2 (Int.repr delta2)). Proof. intros. inv H2; inv H3. auto. Qed. Lemma eval_condition_lessdef: forall cond vl1 vl2 b m1 m2, Val.lessdef_list vl1 vl2 -> Mem.extends m1 m2 -> eval_condition cond vl1 m1 = Some b -> eval_condition cond vl2 m2 = Some b. Proof. intros. eapply eval_condition_inj with (f := fun b => Some(b, 0)) (m1 := m1). apply valid_pointer_extends; auto. apply weak_valid_pointer_extends; auto. apply weak_valid_pointer_no_overflow_extends. apply valid_different_pointers_extends; auto. rewrite <- val_list_inject_lessdef. eauto. auto. Qed. Lemma eval_operation_lessdef: forall sp op vl1 vl2 v1 m1 m2, Val.lessdef_list vl1 vl2 -> Mem.extends m1 m2 -> eval_operation genv sp op vl1 m1 = Some v1 -> exists v2, eval_operation genv sp op vl2 m2 = Some v2 /\ Val.lessdef v1 v2. Proof. intros. rewrite val_list_inject_lessdef in H. assert (exists v2 : val, eval_operation genv sp op vl2 m2 = Some v2 /\ val_inject (fun b => Some(b, 0)) v1 v2). eapply eval_operation_inj with (m1 := m1) (sp1 := sp). intros. rewrite <- val_inject_lessdef; auto. apply valid_pointer_extends; auto. apply weak_valid_pointer_extends; auto. apply weak_valid_pointer_no_overflow_extends. apply valid_different_pointers_extends; auto. rewrite <- val_inject_lessdef; auto. eauto. auto. destruct H2 as [v2 [A B]]. exists v2; split; auto. rewrite val_inject_lessdef; auto. Qed. Lemma eval_addressing_lessdef: forall sp addr vl1 vl2 v1, Val.lessdef_list vl1 vl2 -> eval_addressing genv sp addr vl1 = Some v1 -> exists v2, eval_addressing genv sp addr vl2 = Some v2 /\ Val.lessdef v1 v2. Proof. intros. rewrite val_list_inject_lessdef in H. assert (exists v2 : val, eval_addressing genv sp addr vl2 = Some v2 /\ val_inject (fun b => Some(b, 0)) v1 v2). eapply eval_addressing_inj with (sp1 := sp). intros. rewrite <- val_inject_lessdef; auto. rewrite <- val_inject_lessdef; auto. eauto. auto. destruct H1 as [v2 [A B]]. exists v2; split; auto. rewrite val_inject_lessdef; auto. Qed. End EVAL_LESSDEF. (** Compatibility of the evaluation functions with memory injections. *) Section EVAL_INJECT. Variable F V: Type. Variable genv: Genv.t F V. Variable f: meminj. Hypothesis globals: meminj_preserves_globals genv f. Variable sp1: block. Variable sp2: block. Variable delta: Z. Hypothesis sp_inj: f sp1 = Some(sp2, delta). Remark symbol_address_inject: forall id ofs, val_inject f (Genv.symbol_address genv id ofs) (Genv.symbol_address genv id ofs). Proof. intros. unfold Genv.symbol_address. destruct (Genv.find_symbol genv id) eqn:?; auto. exploit (proj1 globals); eauto. intros. econstructor; eauto. rewrite Int.add_zero; auto. Qed. Lemma eval_condition_inject: forall cond vl1 vl2 b m1 m2, val_list_inject f vl1 vl2 -> Mem.inject f m1 m2 -> eval_condition cond vl1 m1 = Some b -> eval_condition cond vl2 m2 = Some b. Proof. intros. eapply eval_condition_inj with (f := f) (m1 := m1); eauto. intros; eapply Mem.valid_pointer_inject_val; eauto. intros; eapply Mem.weak_valid_pointer_inject_val; eauto. intros; eapply Mem.weak_valid_pointer_inject_no_overflow; eauto. intros; eapply Mem.different_pointers_inject; eauto. Qed. Lemma eval_addressing_inject: forall addr vl1 vl2 v1, val_list_inject f vl1 vl2 -> eval_addressing genv (Vptr sp1 Int.zero) addr vl1 = Some v1 -> exists v2, eval_addressing genv (Vptr sp2 Int.zero) (shift_stack_addressing (Int.repr delta) addr) vl2 = Some v2 /\ val_inject f v1 v2. Proof. intros. rewrite eval_shift_stack_addressing. simpl. eapply eval_addressing_inj with (sp1 := Vptr sp1 Int.zero); eauto. exact symbol_address_inject. Qed. Lemma eval_operation_inject: forall op vl1 vl2 v1 m1 m2, val_list_inject f vl1 vl2 -> Mem.inject f m1 m2 -> eval_operation genv (Vptr sp1 Int.zero) op vl1 m1 = Some v1 -> exists v2, eval_operation genv (Vptr sp2 Int.zero) (shift_stack_operation (Int.repr delta) op) vl2 m2 = Some v2 /\ val_inject f v1 v2. Proof. intros. rewrite eval_shift_stack_operation. simpl. eapply eval_operation_inj with (sp1 := Vptr sp1 Int.zero) (m1 := m1); eauto. exact symbol_address_inject. intros; eapply Mem.valid_pointer_inject_val; eauto. intros; eapply Mem.weak_valid_pointer_inject_val; eauto. intros; eapply Mem.weak_valid_pointer_inject_no_overflow; eauto. intros; eapply Mem.different_pointers_inject; eauto. Qed. End EVAL_INJECT.