89 lines
3.7 KiB
OCaml
89 lines
3.7 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 1999 Institut National de Recherche en Informatique et *)
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(* en Automatique. Distributed only by permission. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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(* Combine heap allocations occurring in the same basic block *)
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open Mach
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type allocation_state =
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No_alloc (* no allocation is pending *)
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| Pending_alloc of Reg.t * int (* an allocation is pending *)
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(* The arguments of Pending_alloc(reg, ofs) are:
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reg the register holding the result of the last allocation
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ofs the alloc position in the allocated block *)
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let allocated_size = function
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No_alloc -> 0
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| Pending_alloc(reg, ofs) -> ofs
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let rec combine i allocstate =
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match i.desc with
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Iend | Ireturn | Iexit | Iraise ->
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(i, allocated_size allocstate)
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| Iop(Ialloc sz) ->
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begin match allocstate with
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No_alloc ->
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let (newnext, newsz) =
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combine i.next (Pending_alloc(i.res.(0), sz)) in
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(instr_cons (Iop(Ialloc newsz)) i.arg i.res newnext, 0)
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| Pending_alloc(reg, ofs) ->
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if ofs + sz < Config.max_young_wosize then begin
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let (newnext, newsz) =
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combine i.next (Pending_alloc(reg, ofs + sz)) in
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(instr_cons (Iop(Iintop_imm(Iadd, ofs))) [| reg |] i.res newnext,
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newsz)
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end else begin
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let (newnext, newsz) =
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combine i.next (Pending_alloc(i.res.(0), sz)) in
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(instr_cons (Iop(Ialloc newsz)) i.arg i.res newnext, ofs)
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end
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end
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| Iop(Icall_ind | Icall_imm _ | Iextcall(_, _) |
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Itailcall_ind | Itailcall_imm _) ->
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let newnext = combine_restart i.next in
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(instr_cons i.desc i.arg i.res newnext, allocated_size allocstate)
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| Iop op ->
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let (newnext, sz) = combine i.next allocstate in
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(instr_cons i.desc i.arg i.res newnext, sz)
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| Iifthenelse(test, ifso, ifnot) ->
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let newifso = combine_restart ifso in
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let newifnot = combine_restart ifnot in
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let newnext = combine_restart i.next in
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(instr_cons (Iifthenelse(test, newifso, newifnot)) i.arg i.res newnext,
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allocated_size allocstate)
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| Iswitch(table, cases) ->
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let newcases = Array.map combine_restart cases in
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let newnext = combine_restart i.next in
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(instr_cons (Iswitch(table, newcases)) i.arg i.res newnext,
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allocated_size allocstate)
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| Iloop(body) ->
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let newbody = combine_restart body in
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(instr_cons (Iloop(newbody)) i.arg i.res i.next,
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allocated_size allocstate)
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| Icatch(body, handler) ->
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let (newbody, sz) = combine body allocstate in
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let newhandler = combine_restart handler in
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let newnext = combine_restart i.next in
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(instr_cons (Icatch(newbody, newhandler)) i.arg i.res newnext, sz)
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| Itrywith(body, handler) ->
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let (newbody, sz) = combine body allocstate in
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let newhandler = combine_restart handler in
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let newnext = combine_restart i.next in
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(instr_cons (Itrywith(newbody, newhandler)) i.arg i.res newnext, sz)
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and combine_restart i =
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let (newi, _) = combine i No_alloc in newi
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let fundecl f =
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{f with fun_body = combine_restart f.fun_body}
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