140 lines
4.6 KiB
OCaml
140 lines
4.6 KiB
OCaml
(***********************************************************************)
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(* *)
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(* OCaml *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1996 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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(* Insert load/stores for pseudoregs that got assigned to stack locations. *)
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open Misc
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open Reg
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open Mach
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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 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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class reload_generic = object (self)
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val mutable redo_regalloc = false
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method 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 _ ->
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redo_regalloc <- true;
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let newr = Reg.clone r in
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(* Strongly discourage spilling this register *)
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newr.spill_cost <- 100000;
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newr
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method private makeregs rv =
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let n = Array.length rv in
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let newv = Array.create n Reg.dummy in
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for i = 0 to n-1 do newv.(i) <- self#makereg rv.(i) done;
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newv
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method private makereg1 rv =
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let newv = Array.copy rv in
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newv.(0) <- self#makereg rv.(0);
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newv
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method reload_operation op arg res =
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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 arg.(0), res.(0) with
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{loc = Stack s1}, {loc = Stack s2} when s1 <> s2 ->
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([| self#makereg arg.(0) |], res)
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| _ ->
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(arg, res)
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end
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| _ ->
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(self#makeregs arg, self#makeregs res)
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method reload_test tst args =
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self#makeregs args
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method private reload i =
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match i.desc with
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(* For function calls, returns, etc: the arguments and results are
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already at the correct position (e.g. on stack for some arguments).
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However, something needs to be done for the function pointer in
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indirect calls. *)
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Iend | Ireturn | Iop(Itailcall_imm _) | Iraise _ -> i
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| Iop(Itailcall_ind) ->
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let newarg = self#makereg1 i.arg in
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insert_moves i.arg newarg
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{i with arg = newarg}
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| Iop(Icall_imm _ | Iextcall _) ->
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{i with next = self#reload i.next}
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| Iop(Icall_ind) ->
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let newarg = self#makereg1 i.arg in
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insert_moves i.arg newarg
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{i with arg = newarg; next = self#reload i.next}
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| Iop op ->
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let (newarg, newres) = self#reload_operation op i.arg i.res in
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insert_moves i.arg newarg
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{i with arg = newarg; res = newres; next =
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(insert_moves newres i.res
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(self#reload i.next))}
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| Iifthenelse(tst, ifso, ifnot) ->
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let newarg = self#reload_test tst i.arg in
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insert_moves i.arg newarg
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(instr_cons
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(Iifthenelse(tst, self#reload ifso, self#reload ifnot)) newarg [||]
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(self#reload i.next))
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| Iswitch(index, cases) ->
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let newarg = self#makeregs i.arg in
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insert_moves i.arg newarg
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(instr_cons (Iswitch(index, Array.map (self#reload) cases)) newarg [||]
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(self#reload i.next))
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| Iloop body ->
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instr_cons (Iloop(self#reload body)) [||] [||] (self#reload i.next)
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| Icatch(nfail, body, handler) ->
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instr_cons
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(Icatch(nfail, self#reload body, self#reload handler)) [||] [||]
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(self#reload i.next)
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| Iexit i ->
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instr_cons (Iexit i) [||] [||] dummy_instr
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| Itrywith(body, handler) ->
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instr_cons (Itrywith(self#reload body, self#reload handler)) [||] [||]
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(self#reload i.next)
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method fundecl f =
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redo_regalloc <- false;
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let new_body = self#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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fun_dbg = f.fun_dbg},
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redo_regalloc)
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end
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