Module Op


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: 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 (* signed integer comparison *)
  | Ccompu: comparison -> condition (* unsigned integer comparison *)
  | Ccompimm: comparison -> int -> condition (* signed integer comparison with a constant *)
  | Ccompuimm: comparison -> int -> condition (* unsigned integer comparison with a constant *)
  | Ccompf: comparison -> condition (* 64-bit floating-point comparison *)
  | Cnotcompf: comparison -> condition (* negation of a floating-point comparison *)
  | Ccompfs: comparison -> condition (* 32-bit floating-point comparison *)
  | Cnotcompfs: comparison -> condition (* negation of a floating-point comparison *)
  | Cmaskzero: int -> condition (* test (arg & constant) == 0 *)
  | Cmasknotzero: int -> condition. (* test (arg & constant) != 0 *)

Addressing modes. r1, r2, etc, are the arguments to the addressing.

Inductive addressing: Type :=
  | Aindexed: int -> addressing (* Address is r1 + offset *)
  | Aindexed2: int -> addressing (* Address is r1 + r2 + offset *)
  | Ascaled: int -> int -> addressing (* Address is r1 * scale + offset *)
  | Aindexed2scaled: int -> int -> addressing
  | Aglobal: ident -> int -> addressing (* Address is symbol + offset *)
  | Abased: ident -> int -> addressing (* Address is symbol + offset + r1 *)
  | Abasedscaled: int -> ident -> int -> addressing (* Address is symbol + offset + r1 * scale *)
  | Ainstack: int -> addressing. (* 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 (* rd = r1 *)
  | Ointconst: int -> operation (* rd is set to the given integer constant *)
  | Ofloatconst: float -> operation (* rd is set to the given float constant *)
  | Osingleconst: float32 -> operation (* rd is set to the given float constant *)
  | Oindirectsymbol: ident -> operation (* rd is set to the address of the symbol *)
  | Ocast8signed: operation (* rd is 8-bit sign extension of r1 *)
  | Ocast8unsigned: operation (* rd is 8-bit zero extension of r1 *)
  | Ocast16signed: operation (* rd is 16-bit sign extension of r1 *)
  | Ocast16unsigned: operation (* rd is 16-bit zero extension of r1 *)
  | Oneg: operation (* rd = - r1 *)
  | Osub: operation (* rd = r1 - r2 *)
  | Omul: operation (* rd = r1 * r2 *)
  | Omulimm: int -> operation (* rd = r1 * n *)
  | Omulhs: operation (* rd = high part of r1 * r2, signed *)
  | Omulhu: operation (* rd = high part of r1 * r2, unsigned *)
  | Odiv: operation (* rd = r1 / r2 (signed) *)
  | Odivu: operation (* rd = r1 / r2 (unsigned) *)
  | Omod: operation (* rd = r1 % r2 (signed) *)
  | Omodu: operation (* rd = r1 % r2 (unsigned) *)
  | Oand: operation (* rd = r1 & r2 *)
  | Oandimm: int -> operation (* rd = r1 & n *)
  | Oor: operation (* rd = r1 | r2 *)
  | Oorimm: int -> operation (* rd = r1 | n *)
  | Oxor: operation (* rd = r1 ^ r2 *)
  | Oxorimm: int -> operation (* rd = r1 ^ n *)
  | Onot: operation (* rd = ~r1 *)
  | Oshl: operation (* rd = r1 << r2 *)
  | Oshlimm: int -> operation (* rd = r1 << n *)
  | Oshr: operation (* rd = r1 >> r2 (signed) *)
  | Oshrimm: int -> operation (* rd = r1 >> n (signed) *)
  | Oshrximm: int -> operation (* rd = r1 / 2^n (signed) *)
  | Oshru: operation (* rd = r1 >> r2 (unsigned) *)
  | Oshruimm: int -> operation (* rd = r1 >> n (unsigned) *)
  | Ororimm: int -> operation (* rotate right immediate *)
  | Oshldimm: int -> operation (* rd = r1 << n | r2 >> (32-n) *)
  | Olea: addressing -> operation (* effective address *)
  | Onegf: operation (* rd = - r1 *)
  | Oabsf: operation (* rd = abs(r1) *)
  | Oaddf: operation (* rd = r1 + r2 *)
  | Osubf: operation (* rd = r1 - r2 *)
  | Omulf: operation (* rd = r1 * r2 *)
  | Odivf: operation (* rd = r1 / r2 *)
  | Onegfs: operation (* rd = - r1 *)
  | Oabsfs: operation (* rd = abs(r1) *)
  | Oaddfs: operation (* rd = r1 + r2 *)
  | Osubfs: operation (* rd = r1 - r2 *)
  | Omulfs: operation (* rd = r1 * r2 *)
  | Odivfs: operation (* rd = r1 / r2 *)
  | Osingleoffloat: operation (* rd is r1 truncated to single-precision float *)
  | Ofloatofsingle: operation (* rd is r1 extended to double-precision float *)
  | Ointoffloat: operation (* rd = signed_int_of_float64(r1) *)
  | Ofloatofint: operation (* rd = float64_of_signed_int(r1) *)
  | Ointofsingle: operation (* rd = signed_int_of_float32(r1) *)
  | Osingleofint: operation (* rd = float32_of_signed_int(r1) *)
  | Omakelong: operation (* rd = r1 << 32 | r2 *)
  | Olowlong: operation (* rd = low-word(r1) *)
  | Ohighlong: operation (* rd = high-word(r1) *)
  | Ocmp: condition -> operation. (* 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)
  | 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
  | Ocmp (Ccompuimm _ _) => 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; auto; congruence.
Qed.

Global variables mentioned in an operation or addressing mode

Definition globals_addressing (addr: addressing) : list ident :=
  match addr with
  | Aglobal s n => s :: nil
  | Abased s n => s :: nil
  | Abasedscaled sc s n => s :: nil
  | _ => nil
  end.

Definition globals_operation (op: operation) : list ident :=
  match op with
  | Oindirectsymbol s => s :: nil
  | Olea addr => globals_addressing addr
  | _ => nil
  end.

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 F1 F2 V1 V2: Type.
Variable ge1: Genv.t F1 V1.
Variable ge2: Genv.t F2 V2.
Variable f: meminj.

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.inject_list _ nil _ |- _ ] =>
      inv H; InvInject
  | [ H: Val.inject_list _ (_ :: _) _ |- _ ] =>
      inv H; InvInject
  | _ => idtac
  end.

Lemma eval_condition_inj:
  forall cond vl1 vl2 b,
  Val.inject_list 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,
  (forall id ofs,
      In id (globals_addressing addr) ->
      Val.inject f (Genv.symbol_address ge1 id ofs) (Genv.symbol_address ge2 id ofs)) ->
  Val.inject f sp1 sp2 ->
  Val.inject_list f vl1 vl2 ->
  eval_addressing ge1 sp1 addr vl1 = Some v1 ->
  exists v2, eval_addressing ge2 sp2 addr vl2 = Some v2 /\ Val.inject f v1 v2.
Proof.
  intros. destruct addr; simpl in H2; 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 H5; simpl; auto.
  apply Values.Val.add_inject; auto. apply Values.Val.add_inject; auto. inv H3; simpl; auto.
  apply H; simpl; auto.
  apply Values.Val.add_inject; auto. apply H; simpl; auto.
  apply Values.Val.add_inject; auto. apply H; simpl; auto. inv H5; simpl; auto.
  apply Values.Val.add_inject; auto.
Qed.

Lemma eval_operation_inj:
  forall op sp1 vl1 sp2 vl2 v1,
  (forall id ofs,
      In id (globals_operation op) ->
      Val.inject f (Genv.symbol_address ge1 id ofs) (Genv.symbol_address ge2 id ofs)) ->
  Val.inject f sp1 sp2 ->
  Val.inject_list f vl1 vl2 ->
  eval_operation ge1 sp1 op vl1 m1 = Some v1 ->
  exists v2, eval_operation ge2 sp2 op vl2 m2 = Some v2 /\ Val.inject f v1 v2.
Proof.
  intros until v1; intros GL; intros. destruct op; simpl in H1; simpl; FuncInv; InvInject; TrivialExists.
  apply GL; simpl; auto.
  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_inject_list_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_inject_list_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).
  apply valid_pointer_extends; auto.
  apply weak_valid_pointer_extends; auto.
  apply weak_valid_pointer_no_overflow_extends.
  apply valid_different_pointers_extends; auto.
  intros. apply val_inject_lessdef. auto.
  apply 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_inject_list_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.inject_list 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.inject_list 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.
  intros. apply symbol_address_inject.
Qed.

Lemma eval_operation_inject:
  forall op vl1 vl2 v1 m1 m2,
  Val.inject_list 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.
  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.
  intros. apply symbol_address_inject.
Qed.

End EVAL_INJECT.