ocaml/asmcomp/hppa/selection.ml

110 lines
3.8 KiB
OCaml

(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* 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 Q Public License version 1.0. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Instruction selection for the HPPA processor *)
open Misc
open Cmm
open Reg
open Arch
open Proc
open Mach
let shiftadd = function
2 -> Ishift1add
| 4 -> Ishift2add
| 8 -> Ishift3add
| _ -> fatal_error "Proc_hppa.shiftadd"
class selector = object (self)
inherit Selectgen.selector_generic as super
method is_immediate n = (n < 16) && (n >= -16) (* 5 bits *)
method select_addressing = function
Cconst_symbol s ->
(Ibased(s, 0), Ctuple [])
| Cop(Cadda, [Cconst_symbol s; Cconst_int n]) ->
(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(1|2|3 as shift)])]) ->
(Ispecific(shiftadd(1 lsl shift)), [arg1; arg2])
| ((Caddi|Cadda),
[arg2; Cop(Cmuli, [arg1; Cconst_int(2|4|8 as mult)])]) ->
(Ispecific(shiftadd mult), [arg1; arg2])
| ((Caddi|Cadda),
[arg2; Cop(Cmuli, [Cconst_int(2|4|8 as mult); arg1])]) ->
(Ispecific(shiftadd mult), [arg1; arg2])
| (Caddi, [Cop(Clsl, [arg1; Cconst_int(1|2|3 as shift)]); arg2]) ->
(Ispecific(shiftadd(1 lsl shift)), [arg1; arg2])
| (Caddi, [Cop(Cmuli, [arg1; Cconst_int(2|4|8 as mult)]); arg2]) ->
(Ispecific(shiftadd mult), [arg1; arg2])
| (Caddi, [Cop(Cmuli, [Cconst_int(2|4|8 as mult); arg1]); arg2]) ->
(Ispecific(shiftadd mult), [arg1; arg2])
(* Prevent the recognition of some immediate arithmetic operations *)
(* Cmuli : -> Ilsl if power of 2
Cdivi, Cmodi : only if power of 2
Cand, Cor, Cxor : never *)
| (Cmuli, ([arg1; Cconst_int n] as args)) ->
let l = Misc.log2 n in
if n = 1 lsl l
then (Iintop_imm(Ilsl, l), [arg1])
else (Iintop Imul, args)
| (Cmuli, ([Cconst_int n; arg1] as args)) ->
let l = Misc.log2 n in
if n = 1 lsl l
then (Iintop_imm(Ilsl, l), [arg1])
else (Iintop Imul, args)
| (Cmuli, args) -> (Iintop Imul, args)
| (Cdivi, [arg1; Cconst_int n]) when n = 1 lsl (Misc.log2 n) ->
(Iintop_imm(Idiv, n), [arg1])
| (Cdivi, args) -> (Iintop Idiv, args)
| (Cmodi, [arg1; Cconst_int n]) when n = 1 lsl (Misc.log2 n) ->
(Iintop_imm(Imod, n), [arg1])
| (Cmodi, args) -> (Iintop Imod, args)
| (Cand, args) -> (Iintop Iand, args)
| (Cor, args) -> (Iintop Ior, args)
| (Cxor, args) -> (Iintop Ixor, args)
| _ ->
super#select_operation op args
(* Deal with register constraints *)
method insert_op op rs rd =
match op with
Iintop(Idiv | Imod) -> (* handled via calls to millicode *)
let rs' = [|phys_reg 20; phys_reg 19|] (* %r26, %r25 *)
and rd' = [|phys_reg 22|] (* %r29 *) in
self#insert_moves rs rs';
self#insert (Iop op) rs' rd';
self#insert_moves rd' rd;
rd
| _ ->
super#insert_op op rs rd
end
let fundecl f = (new selector)#emit_fundecl f