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(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1997 Institut National de Recherche en Informatique et *)
(* Automatique. Distributed only by permission. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Instruction selection for the Alpha processor *)
open Misc
open Cmm
open Reg
open Arch
open Mach
class selector = object (self)
inherit Selectgen.selector_generic as super
method is_immediate n = digital_asm || (n >= 0 && n <= 255)
method select_addressing = function
(* Force an explicit lda for non-scheduling assemblers,
this allows our scheduler to do a better job. *)
Cconst_symbol s when digital_asm ->
(Ibased(s, 0), Ctuple [])
| Cop(Cadda, [Cconst_symbol s; Cconst_int n]) when digital_asm ->
(Ibased(s, n), Ctuple [])
| Cop(Cadda, [arg; Cconst_int n]) ->
(Iindexed n, arg)
| Cop(Cadda, [arg1; Cop(Caddi, [arg2; Cconst_int n])]) ->
(Iindexed n, Cop(Cadda, [arg1; arg2]))
| arg ->
(Iindexed 0, arg)
method select_operation op args =
match (op, args) with
(* Recognize shift-add operations *)
((Caddi|Cadda),
[arg2; Cop(Clsl, [arg1; Cconst_int(2|3 as shift)])]) ->
(Ispecific(if shift = 2 then Iadd4 else Iadd8), [arg1; arg2])
| ((Caddi|Cadda),
[arg2; Cop(Cmuli, [arg1; Cconst_int(4|8 as mult)])]) ->
(Ispecific(if mult = 4 then Iadd4 else Iadd8), [arg1; arg2])
| ((Caddi|Cadda),
[arg2; Cop(Cmuli, [Cconst_int(4|8 as mult); arg1])]) ->
(Ispecific(if mult = 4 then Iadd4 else Iadd8), [arg1; arg2])
| (Caddi, [Cop(Clsl, [arg1; Cconst_int(2|3 as shift)]); arg2]) ->
(Ispecific(if shift = 2 then Iadd4 else Iadd8), [arg1; arg2])
| (Caddi, [Cop(Cmuli, [arg1; Cconst_int(4|8 as mult)]); arg2]) ->
(Ispecific(if mult = 4 then Iadd4 else Iadd8), [arg1; arg2])
| (Caddi, [Cop(Cmuli, [Cconst_int(4|8 as mult); arg1]); arg2]) ->
(Ispecific(if mult = 4 then Iadd4 else Iadd8), [arg1; arg2])
| (Csubi, [Cop(Clsl, [arg1; Cconst_int(2|3 as shift)]); arg2]) ->
(Ispecific(if shift = 2 then Isub4 else Isub8), [arg1; arg2])
| (Csubi, [Cop(Cmuli, [Cconst_int(4|8 as mult); arg1]); arg2]) ->
(Ispecific(if mult = 4 then Isub4 else Isub8), [arg1; arg2])
(* Work around various limitations of the GNU assembler *)
| ((Caddi|Cadda), [arg1; Cconst_int n]) when self#is_immediate (-n) ->
(Iintop_imm(Isub, -n), [arg1])
| (Cdivi, [arg1; Cconst_int n])
when (not digital_asm) && n <> 1 lsl (Misc.log2 n) ->
(Iintop Idiv, args)
| (Cmodi, [arg1; Cconst_int n])
when (not digital_asm) && n <> 1 lsl (Misc.log2 n) ->
(Iintop Imod, args)
| _ ->
super#select_operation op args
end
let fundecl f = (new selector)#emit_fundecl f
|
