Module Machregs

Require Import String.
Require Import Coqlib.
Require Import Decidableplus.
Require Import Maps.
Require Import AST.
Require Import Op.

Machine registers

The following type defines the machine registers that can be referenced as locations. These include:

Integer registers that can be allocated to RTL pseudo-registers (Rxx).
Floating-point registers that can be allocated to RTL pseudo-registers (Fxx).

The type mreg does not include special-purpose or reserved machine registers such as the stack pointer (GPR1), the small data area pointers (GPR2, GPR13), and the condition codes.

Inductive mreg: Type :=

Allocatable integer regs

Allocatable float regs

  | F0: mreg
  | F1: mreg | F2: mreg | F3: mreg | F4: mreg
  | F5: mreg | F6: mreg | F7: mreg | F8: mreg
  | F9: mreg | F10: mreg | F11: mreg | F12: mreg
  | F13: mreg | F14: mreg | F15: mreg
  | F16: mreg | F17: mreg | F18: mreg | F19: mreg
  | F20: mreg | F21: mreg | F22: mreg | F23: mreg
  | F24: mreg | F25: mreg | F26: mreg | F27: mreg
  | F28: mreg | F29: mreg | F30: mreg | F31: mreg.

Lemma mreg_eq: forall (r1 r2: mreg), {r1 = r2} + {r1 <> r2}.

Proof.

decide equality. Defined.

Global Opaque mreg_eq.

Definition all_mregs :=
     R3 :: R4 :: R5 :: R6 :: R7 :: R8 :: R9 :: R10
  :: R11 :: R12 :: R14 :: R15 :: R16 :: R17 :: R18 :: R19 :: R20
  :: R21 :: R22 :: R23 :: R24 :: R25 :: R26 :: R27 :: R28
  :: R29 :: R30 :: R31
  :: F0 :: F1 :: F2 :: F3 :: F4
  :: F5 :: F6 :: F7 :: F8
  :: F9 :: F10 :: F11 :: F12
  :: F13 :: F14 :: F15
  :: F16 :: F17 :: F18 :: F19
  :: F20 :: F21 :: F22 :: F23
  :: F24 :: F25 :: F26 :: F27
  :: F28 :: F29 :: F30 :: F31 :: nil.

Lemma all_mregs_complete:
  forall (r: mreg), In r all_mregs.

Proof.

assert (forall r, proj_sumbool (In_dec mreg_eq r all_mregs) = true) by (destruct r; reflexivity).
intros. specialize (H r). InvBooleans. auto.
Qed.

Global Instance Decidable_eq_mreg : forall (x y: mreg), Decidable (eq x y) := Decidable_eq mreg_eq.

Global Instance Finite_mreg : Finite mreg := {
  Finite_elements := all_mregs;
  Finite_elements_spec := all_mregs_complete
}.

Definition mreg_type (r: mreg): typ :=
  match r with
  | R3 | R4 | R5 | R6 | R7 | R8 | R9 | R10 | R11 | R12
  | R14 | R15 | R16 | R17 | R18 | R19 | R20 | R21 | R22 | R23 | R24
  | R25 | R26 | R27 | R28 | R29 | R30 | R31 => if Archi.ppc64 then Tany64 else Tany32
  | F0 | F1 | F2 | F3 | F4 | F5 | F6 | F7
  | F8 | F9 | F10 | F11 | F12 | F13 | F14 | F15
  | F16 | F17 | F18 | F19 | F20 | F21 | F22 | F23
  | F24 | F25 | F26 | F27 | F28 | F29 | F30 | F31 => Tany64
  end.

Open Scope positive_scope.

Module IndexedMreg <: INDEXED_TYPE.
  Definition t := mreg.
  Definition eq := mreg_eq.
  Definition index (r: mreg): positive :=
    match r with
    | R3 => 1 | R4 => 2 | R5 => 3 | R6 => 4
    | R7 => 5 | R8 => 6 | R9 => 7 | R10 => 8
    | R11 => 9 | R12 => 10
    | R14 => 11 | R15 => 12 | R16 => 13
    | R17 => 14 | R18 => 15 | R19 => 16 | R20 => 17
    | R21 => 18 | R22 => 19 | R23 => 20 | R24 => 21
    | R25 => 22 | R26 => 23 | R27 => 24 | R28 => 25
    | R29 => 26 | R30 => 27 | R31 => 28
    | F0 => 29
    | F1 => 30 | F2 => 31 | F3 => 32 | F4 => 33
    | F5 => 34 | F6 => 35 | F7 => 36 | F8 => 37
    | F9 => 38 | F10 => 39 | F11 => 40 | F12 => 41
    | F13 => 42 | F14 => 43 | F15 => 44
    | F16 => 45 | F17 => 46 | F18 => 47 | F19 => 48
    | F20 => 49 | F21 => 50 | F22 => 51 | F23 => 52
    | F24 => 53 | F25 => 54 | F26 => 55 | F27 => 56
    | F28 => 57 | F29 => 58 | F30 => 59 | F31 => 60
    end.
  Lemma index_inj:
    forall r1 r2, index r1 = index r2 -> r1 = r2.

Proof.

decide_goal.
Qed.

End IndexedMreg.

Definition is_stack_reg (r: mreg) : bool := false.

Names of registers

Local Open Scope string_scope.

Definition register_names :=
  ("R3", R3) :: ("R4", R4) :: ("R5", R5) :: ("R6", R6) ::
  ("R7", R7) :: ("R8", R8) :: ("R9", R9) :: ("R10", R10) ::
  ("R11", R11) :: ("R12", R12) ::
  ("R14", R14) :: ("R15", R15) :: ("R16", R16) ::
  ("R17", R17) :: ("R18", R18) :: ("R19", R19) :: ("R20", R20) ::
  ("R21", R21) :: ("R22", R22) :: ("R23", R23) :: ("R24", R24) ::
  ("R25", R25) :: ("R26", R26) :: ("R27", R27) :: ("R28", R28) ::
  ("R29", R29) :: ("R30", R30) :: ("R31", R31) ::
  ("F0", F0) :: ("F1", F1) :: ("F2", F2) :: ("F3", F3) :: ("F4", F4) ::
  ("F5", F5) :: ("F6", F6) :: ("F7", F7) :: ("F8", F8) ::
  ("F9", F9) :: ("F10", F10) :: ("F11", F11) :: ("F12", F12) ::
  ("F13", F13) :: ("F14", F14) :: ("F15", F15) ::
  ("F16", F16) :: ("F17", F17) :: ("F18", F18) :: ("F19", F19) ::
  ("F20", F20) :: ("F21", F21) :: ("F22", F22) :: ("F23", F23) ::
  ("F24", F24) :: ("F25", F25) :: ("F26", F26) :: ("F27", F27) ::
  ("F28", F28) :: ("F29", F29) :: ("F30", F30) :: ("F31", F31) :: nil.

Definition register_by_name (s: string) : option mreg :=
  let fix assoc (l: list (string * mreg)) : option mreg :=
    match l with
    | nil => None
    | (s1, r1) :: l' => if string_dec s s1 then Some r1 else assoc l'
    end
  in assoc register_names.

Destroyed registers, preferred registers

Definition destroyed_by_cond (cond: condition): list mreg := nil.

Definition destroyed_by_op (op: operation): list mreg :=
  match op with
  | Ofloatconst _ => R12 :: nil
  | Osingleconst _ => R12 :: nil
  | Olongconst _ => R12 :: nil
  | Ointoffloat => F13 :: nil
  | Olongoffloat => F13 :: nil
  | Oaddlimm _ => R12 :: nil
  | Oandlimm _ => R12 :: nil
  | Oorlimm _ => R12 :: nil
  | Oxorlimm _ => R12 :: nil
  | Orolml _ _ => R12 :: nil
  | Ocmp c => destroyed_by_cond c
  | _ => nil
  end.

Definition destroyed_by_load (chunk: memory_chunk) (addr: addressing): list mreg :=
  R12 :: nil.

Definition destroyed_by_store (chunk: memory_chunk) (addr: addressing): list mreg :=
  R11 :: R12 :: nil.

Definition destroyed_by_jumptable: list mreg :=
  R12 :: nil.

Fixpoint destroyed_by_clobber (cl: list string): list mreg :=
  match cl with
  | nil => nil
  | c1 :: cl =>
      match register_by_name c1 with
      | Some r => r :: destroyed_by_clobber cl
      | None => destroyed_by_clobber cl
      end
  end.

Definition destroyed_by_builtin (ef: external_function): list mreg :=
  match ef with
  | EF_builtin id sg =>
    if string_dec id "__builtin_set_spr64" then R10::nil
    else if string_dec id "__builtin_atomic_exchange" then R10::nil
    else if string_dec id "__builtin_atomic_compare_exchange" then R10::R11::nil
    else F13 :: nil
  | EF_vload _ => R11 :: nil
  | EF_vstore Mint64 => R10 :: R11 :: R12 :: nil
  | EF_vstore _ => R11 :: R12 :: nil
  | EF_memcpy _ _ => R11 :: R12 :: F13 :: nil
  | EF_inline_asm txt sg clob => destroyed_by_clobber clob
  | _ => nil
  end.

Definition destroyed_by_setstack (ty: typ): list mreg :=
  nil.

Definition destroyed_at_function_entry: list mreg :=
  nil.

Definition destroyed_at_indirect_call: list mreg :=
  nil.

Definition temp_for_parent_frame: mreg :=
  R11.

Definition mregs_for_operation (op: operation): list (option mreg) * option mreg :=
  (nil, None).

Definition mregs_for_builtin (ef: external_function): list (option mreg) * list (option mreg) :=
  match ef with
    | EF_builtin id sg =>
      if string_dec id "__builtin_atomic_exchange" then ((Some R3)::(Some R4)::(Some R5)::nil,nil)
      else if string_dec id "__builtin_sync_fetch_and_add" then ((Some R4)::(Some R5)::nil,(Some R3)::nil)
      else if string_dec id "__builtin_atomic_compare_exchange" then ((Some R4)::(Some R5)::(Some R6)::nil, (Some R3):: nil)
      else (nil, nil)
    | _ => (nil, nil)
  end.

Global Opaque
    destroyed_by_op destroyed_by_load destroyed_by_store
    destroyed_by_cond destroyed_by_jumptable destroyed_by_builtin
    destroyed_at_indirect_call
    destroyed_by_setstack destroyed_at_function_entry temp_for_parent_frame
    mregs_for_operation mregs_for_builtin.

Two-address operations. Return true if the first argument and the result must be in the same location *and* are unconstrained by mregs_for_operation.

Definition two_address_op (op: operation) : bool :=
  match op with
  | Oroli _ _ => true
  | Olowlong => true
  | Ofloatofsingle => true
  | _ => false
  end.

Definition builtin_constraints (ef: external_function) :
                                       list builtin_arg_constraint :=
  match ef with
  | EF_builtin id sg =>
      if string_dec id "__builtin_get_spr" then OK_const :: nil
      else if string_dec id "__builtin_get_spr64" then OK_const :: nil
      else if string_dec id "__builtin_set_spr" then OK_const :: OK_default :: nil
      else if string_dec id "__builtin_set_spr64" then OK_const :: OK_default :: nil
      else if string_dec id "__builtin_prefetch" then OK_default :: OK_const :: OK_const :: nil
      else if string_dec id "__builtin_dcbtls" then OK_default :: OK_const :: nil
      else if string_dec id "__builtin_icbtls" then OK_default :: OK_const :: nil
      else if string_dec id "__builtin_mbar" then OK_const :: nil
      else if string_dec id "__builtin_mr" then OK_const :: OK_const :: nil
      else nil
  | EF_vload _ => OK_addressing :: nil
  | EF_vstore _ => OK_addressing :: OK_default :: nil
  | EF_memcpy _ _ => OK_addrstack :: OK_addrstack :: nil
  | EF_annot kind txt targs => map (fun _ => OK_all) targs
  | EF_debug kind txt targs => map (fun _ => OK_all) targs
  | _ => nil
  end.