122 lines
4.2 KiB
OCaml
122 lines
4.2 KiB
OCaml
(***********************************************************************)
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(* *)
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(* Caml Special Light *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1995 Institut National de Recherche en Informatique et *)
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(* Automatique. Distributed only by permission. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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(* Insert load/stores for pseudoregs that got assigned to stack locations.
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Insert moves to comply with calling conventions, etc. *)
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open Misc
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open Reg
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open Mach
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let redo_regalloc = ref false
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let access_stack r =
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try
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for i = 0 to Array.length r - 1 do
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match r.(i).loc with Stack _ -> raise Exit | _ -> ()
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done;
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false
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with Exit ->
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true
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let makereg r =
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match r.loc with
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Unknown -> fatal_error "Reload.makereg"
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| Reg _ -> r
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| Stack _ -> redo_regalloc := true; Reg.clone r
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let makeregs rv =
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let n = Array.length rv in
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let newv = Array.new n Reg.dummy in
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for i = 0 to n-1 do newv.(i) <- makereg rv.(i) done;
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newv
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let insert_move src dst next =
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if src.loc = dst.loc
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then next
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else instr_cons (Iop Imove) [|src|] [|dst|] next
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let insert_moves src dst next =
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let rec insmoves i =
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if i >= Array.length src
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then next
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else insert_move src.(i) dst.(i) (insmoves (i+1))
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in insmoves 0
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let rec reload i =
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match i.desc with
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Iend | Ireturn | Iop Itailcall_ind | Iop(Itailcall_imm _) | Iraise -> i
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| Iop(Icall_ind | Icall_imm _ | Iextcall(_, _)) ->
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(* Don't do anything, the arguments and results are already at
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the correct position (e.g. on stack for some arguments). *)
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instr_cons_live i.desc i.arg i.res i.live (reload i.next)
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| Iop op ->
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(* Let the machine description tell us whether some arguments / results
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can reside on the stack *)
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let (newarg, newres) =
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try
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Proc.reload_operation makereg op i.arg i.res
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with Proc.Use_default ->
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(* By default, assume that arguments and results must reside
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in hardware registers. For moves, allow one arg or one
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res to be stack-allocated, but do something for
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stack-to-stack moves *)
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match op with
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Imove | Ireload | Ispill ->
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begin match i.arg.(0), i.res.(0) with
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{loc = Stack s1}, {loc = Stack s2} when s1 <> s2 ->
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([| makereg i.arg.(0) |], i.res)
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| _ ->
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(i.arg, i.res)
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end
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| _ ->
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(makeregs i.arg, makeregs i.res) in
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insert_moves i.arg newarg
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(instr_cons_live i.desc newarg newres i.live
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(insert_moves newres i.res
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(reload i.next)))
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| Iifthenelse(tst, ifso, ifnot) ->
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(* Let the machine description tell us whether some arguments / results
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can reside on the stack *)
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let newarg =
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try
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Proc.reload_test makereg tst i.arg
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with Proc.Use_default ->
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makeregs i.arg in
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insert_moves i.arg newarg
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(instr_cons (Iifthenelse(tst, reload ifso, reload ifnot)) newarg [||]
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(reload i.next))
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| Iswitch(index, cases) ->
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let newarg = makeregs i.arg in
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insert_moves i.arg newarg
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(instr_cons (Iswitch(index, Array.map reload cases)) newarg [||]
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(reload i.next))
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| Iloop body ->
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instr_cons (Iloop(reload body)) [||] [||] (reload i.next)
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| Icatch(body, handler) ->
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instr_cons (Icatch(reload body, reload handler)) [||] [||]
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(reload i.next)
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| Iexit ->
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instr_cons Iexit [||] [||] dummy_instr
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| Itrywith(body, handler) ->
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instr_cons (Itrywith(reload body, reload handler)) [||] [||]
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(reload i.next)
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let fundecl f =
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redo_regalloc := false;
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let new_body = reload f.fun_body in
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({fun_name = f.fun_name; fun_args = f.fun_args;
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fun_body = new_body; fun_fast = f.fun_fast},
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!redo_regalloc)
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