84 lines
3.5 KiB
OCaml
84 lines
3.5 KiB
OCaml
(***********************************************************************)
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(* *)
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(* Objective Caml *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1997 Institut National de Recherche en Informatique et *)
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(* en Automatique. All rights reserved. This file is distributed *)
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(* under the terms of the Q Public License version 1.0. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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(* Instruction selection for the Alpha processor *)
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open Misc
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open Cmm
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open Reg
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open Arch
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open Mach
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class selector = object (self)
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inherit Selectgen.selector_generic as super
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method is_immediate n = digital_asm || (n >= 0 && n <= 255)
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method select_addressing = function
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(* Force an explicit lda for non-scheduling assemblers,
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this allows our scheduler to do a better job. *)
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Cconst_symbol s when digital_asm ->
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(Ibased(s, 0), Ctuple [])
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| Cop((Cadda | Caddi), [Cconst_symbol s; Cconst_int n]) when digital_asm ->
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(Ibased(s, n), Ctuple [])
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| Cop((Cadda | Caddi), [arg; Cconst_int n]) ->
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(Iindexed n, arg)
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| Cop((Cadda | Caddi), [arg1; Cop(Caddi, [arg2; Cconst_int n])]) ->
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(Iindexed n, Cop(Cadda, [arg1; arg2]))
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| arg ->
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(Iindexed 0, arg)
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method select_operation op args =
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match (op, args) with
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(* Recognize shift-add operations *)
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((Caddi|Cadda),
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[arg2; Cop(Clsl, [arg1; Cconst_int(2|3 as shift)])]) ->
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(Ispecific(if shift = 2 then Iadd4 else Iadd8), [arg1; arg2])
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| ((Caddi|Cadda),
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[arg2; Cop(Cmuli, [arg1; Cconst_int(4|8 as mult)])]) ->
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(Ispecific(if mult = 4 then Iadd4 else Iadd8), [arg1; arg2])
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| ((Caddi|Cadda),
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[arg2; Cop(Cmuli, [Cconst_int(4|8 as mult); arg1])]) ->
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(Ispecific(if mult = 4 then Iadd4 else Iadd8), [arg1; arg2])
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| (Caddi, [Cop(Clsl, [arg1; Cconst_int(2|3 as shift)]); arg2]) ->
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(Ispecific(if shift = 2 then Iadd4 else Iadd8), [arg1; arg2])
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| (Caddi, [Cop(Cmuli, [arg1; Cconst_int(4|8 as mult)]); arg2]) ->
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(Ispecific(if mult = 4 then Iadd4 else Iadd8), [arg1; arg2])
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| (Caddi, [Cop(Cmuli, [Cconst_int(4|8 as mult); arg1]); arg2]) ->
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(Ispecific(if mult = 4 then Iadd4 else Iadd8), [arg1; arg2])
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| (Csubi, [Cop(Clsl, [arg1; Cconst_int(2|3 as shift)]); arg2]) ->
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(Ispecific(if shift = 2 then Isub4 else Isub8), [arg1; arg2])
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| (Csubi, [Cop(Cmuli, [Cconst_int(4|8 as mult); arg1]); arg2]) ->
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(Ispecific(if mult = 4 then Isub4 else Isub8), [arg1; arg2])
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(* Recognize truncation/normalization of 64-bit integers to 32 bits *)
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| (Casr, [Cop(Clsl, [arg; Cconst_int 32]); Cconst_int 32]) ->
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(Ispecific Itrunc32, [arg])
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(* Work around various limitations of the GNU assembler *)
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| ((Caddi|Cadda), [arg1; Cconst_int n])
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when not (self#is_immediate n) && self#is_immediate (-n) ->
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(Iintop_imm(Isub, -n), [arg1])
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| (Cdivi, [arg1; Cconst_int n])
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when (not digital_asm) && n <> 1 lsl (Misc.log2 n) ->
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(Iintop Idiv, args)
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| (Cmodi, [arg1; Cconst_int n])
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when (not digital_asm) && n <> 1 lsl (Misc.log2 n) ->
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(Iintop Imod, args)
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| _ ->
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super#select_operation op args
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end
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let fundecl f = (new selector)#emit_fundecl f
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