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|
(**************************************************************************)
(* *)
(* OCaml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1999 Institut National de Recherche en Informatique et *)
(* en Automatique. *)
(* *)
(* All rights reserved. This file is distributed under the terms of *)
(* the GNU Lesser General Public License version 2.1, with the *)
(* special exception on linking described in the file LICENSE. *)
(* *)
(**************************************************************************)
(* Combine heap allocations occurring in the same basic block *)
open Mach
type allocation_state =
No_alloc (* no allocation is pending *)
| Pending_alloc of Reg.t * int (* an allocation is pending *)
(* The arguments of Pending_alloc(reg, ofs) are:
reg the register holding the result of the last allocation
ofs the alloc position in the allocated block *)
let allocated_size = function
No_alloc -> 0
| Pending_alloc(_, ofs) -> ofs
let rec combine i allocstate =
match i.desc with
Iend | Ireturn | Iexit _ | Iraise _ ->
(i, allocated_size allocstate)
| Iop(Ialloc { words = sz; _ }) ->
begin match allocstate with
No_alloc ->
let (newnext, newsz) =
combine i.next (Pending_alloc(i.res.(0), sz)) in
(instr_cons_debug (Iop(Ialloc {words = newsz; spacetime_index = 0;
label_after_call_gc = None; }))
i.arg i.res i.dbg newnext, 0)
| Pending_alloc(reg, ofs) ->
if ofs + sz < Config.max_young_wosize * Arch.size_addr then begin
let (newnext, newsz) =
combine i.next (Pending_alloc(reg, ofs + sz)) in
(instr_cons (Iop(Iintop_imm(Iadd, ofs))) [| reg |] i.res newnext,
newsz)
end else begin
let (newnext, newsz) =
combine i.next (Pending_alloc(i.res.(0), sz)) in
(instr_cons_debug (Iop(Ialloc { words = newsz; spacetime_index = 0;
label_after_call_gc = None; }))
i.arg i.res i.dbg newnext, ofs)
end
end
| Iop(Icall_ind _ | Icall_imm _ | Iextcall _ |
Itailcall_ind _ | Itailcall_imm _) ->
let newnext = combine_restart i.next in
(instr_cons_debug i.desc i.arg i.res i.dbg newnext,
allocated_size allocstate)
| Iop _ ->
let (newnext, sz) = combine i.next allocstate in
(instr_cons_debug i.desc i.arg i.res i.dbg newnext, sz)
| Iifthenelse(test, ifso, ifnot) ->
let newifso = combine_restart ifso in
let newifnot = combine_restart ifnot in
let newnext = combine_restart i.next in
(instr_cons (Iifthenelse(test, newifso, newifnot)) i.arg i.res newnext,
allocated_size allocstate)
| Iswitch(table, cases) ->
let newcases = Array.map combine_restart cases in
let newnext = combine_restart i.next in
(instr_cons (Iswitch(table, newcases)) i.arg i.res newnext,
allocated_size allocstate)
| Iloop(body) ->
let newbody = combine_restart body in
(instr_cons (Iloop(newbody)) i.arg i.res i.next,
allocated_size allocstate)
| Icatch(rec_flag, handlers, body) ->
let (newbody, sz) = combine body allocstate in
let newhandlers =
List.map (fun (io, handler) -> io, combine_restart handler) handlers in
let newnext = combine_restart i.next in
(instr_cons (Icatch(rec_flag, newhandlers, newbody))
i.arg i.res newnext, sz)
| Itrywith(body, handler) ->
let (newbody, sz) = combine body allocstate in
let newhandler = combine_restart handler in
let newnext = combine_restart i.next in
(instr_cons (Itrywith(newbody, newhandler)) i.arg i.res newnext, sz)
and combine_restart i =
let (newi, _) = combine i No_alloc in newi
let fundecl f =
if Config.spacetime then f
else {f with fun_body = combine_restart f.fun_body}
|
