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# 2 "asmcomp/power/selection.ml"
(**************************************************************************)
(* *)
(* OCaml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1997 Institut National de Recherche en Informatique et *)
(* en Automatique. *)
(* *)
(* All rights reserved. This file is distributed under the terms of *)
(* the GNU Lesser General Public License version 2.1, with the *)
(* special exception on linking described in the file LICENSE. *)
(* *)
(**************************************************************************)
(* Instruction selection for the Power PC processor *)
open Cmm
open Arch
open Mach
(* Recognition of addressing modes *)
type addressing_expr =
Asymbol of string
| Alinear of expression
| Aadd of expression * expression
let rec select_addr = function
Cconst_symbol (s, _) ->
(Asymbol s, 0, Debuginfo.none)
| Cop((Caddi | Caddv | Cadda), [arg; Cconst_int (m, _)], dbg) ->
let (a, n, _) = select_addr arg in (a, n + m, dbg)
| Cop((Caddi | Caddv | Cadda), [Cconst_int (m, _); arg], dbg) ->
let (a, n, _) = select_addr arg in (a, n + m, dbg)
| Cop((Caddi | Caddv | Cadda), [arg1; arg2], dbg) ->
begin match (select_addr arg1, select_addr arg2) with
((Alinear e1, n1, _), (Alinear e2, n2, _)) ->
(Aadd(e1, e2), n1 + n2, dbg)
| _ ->
(Aadd(arg1, arg2), 0, dbg)
end
| exp ->
(Alinear exp, 0, Debuginfo.none)
let is_immediate n = n <= 0x7FFF && n >= -0x8000
let is_immediate_logical n = n <= 0xFFFF && n >= 0
(* Instruction selection *)
class selector = object (self)
inherit Selectgen.selector_generic as super
method is_immediate_test cmp n =
match cmp with
| Isigned _ -> is_immediate n
| Iunsigned _ -> is_immediate_logical n
method! is_immediate op n =
match op with
| Iadd | Imul -> is_immediate n
| Isub -> is_immediate (-n) (* turned into add opposite *)
| Iand | Ior | Ixor -> is_immediate_logical n
| Icomp c -> self#is_immediate_test c n
| Icheckbound -> 0 <= n && n <= 0x7FFF
(* twlle takes a 16-bit signed immediate but performs an unsigned compare *)
| _ -> super#is_immediate op n
method select_addressing _chunk exp =
match select_addr exp with
(Asymbol s, d, _dbg) ->
(Ibased(s, d), Ctuple [])
| (Alinear e, d, _dbg) ->
(Iindexed d, e)
| (Aadd(e1, e2), d, dbg) ->
if d = 0
then (Iindexed2, Ctuple[e1; e2])
else (Iindexed d, Cop(Cadda, [e1; e2], dbg))
method! select_operation op args dbg =
match (op, args) with
(* Recognize mult-add and mult-sub instructions *)
| (Caddf, [Cop(Cmulf, [arg1; arg2], _); arg3]) ->
(Ispecific Imultaddf, [arg1; arg2; arg3])
| (Caddf, [arg3; Cop(Cmulf, [arg1; arg2], _)]) ->
(Ispecific Imultaddf, [arg1; arg2; arg3])
| (Csubf, [Cop(Cmulf, [arg1; arg2], _); arg3]) ->
(Ispecific Imultsubf, [arg1; arg2; arg3])
| _ ->
super#select_operation op args dbg
end
let fundecl ~future_funcnames f =
(new selector)#emit_fundecl ~future_funcnames f
|
