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|
(**************************************************************************)
(* *)
(* OCaml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 2000 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. *)
(* *)
(**************************************************************************)
open Cmm
open Reg
open Mach
(* Reloading for the AMD64 *)
(* Summary of instruction set constraints:
"S" means either stack or register, "R" means register only.
Operation Res Arg1 Arg2
Imove R S
or S R
Iconst_int S if 32-bit signed, R otherwise
Iconst_float R
Iconst_symbol (not PIC) S
Iconst_symbol (PIC) R
Icall_ind R
Itailcall_ind R
Iload R R R
Istore R R
Iintop(Icomp) R R S
or S S R
Iintop(Imul|Idiv|Imod) R R S
Iintop(Imulh) R R S
Iintop(shift) S S R
Iintop(others) R R S
or S S R
Iintop_imm(Iadd, n)/lea R R
Iintop_imm(others) S S
Inegf...Idivf R R S
Ifloatofint R S
Iintoffloat R S
Ispecific(Ilea) R R R
Ispecific(Ifloatarithmem) R R R
Conditional branches:
Iinttest S R
or R S
Ifloattest R S (or S R if swapped test)
other tests S
*)
let stackp r =
match r.loc with
Stack _ -> true
| _ -> false
class reload = object (self)
inherit Reloadgen.reload_generic as super
method! reload_operation op arg res =
match op with
| Iintop(Iadd|Isub|Iand|Ior|Ixor|Icomp _|Icheckbound _) ->
(* One of the two arguments can reside in the stack, but not both *)
if stackp arg.(0) && stackp arg.(1)
then ([|arg.(0); self#makereg arg.(1)|], res)
else (arg, res)
| Iintop_imm(Iadd, _) when arg.(0).loc <> res.(0).loc ->
(* This add will be turned into a lea; args and results must be
in registers *)
super#reload_operation op arg res
| Iintop(Imulh | Idiv | Imod | Ilsl | Ilsr | Iasr)
| Iintop_imm(_, _) ->
(* The argument(s) and results can be either in register or on stack *)
(* Note: Imulh, Idiv, Imod: arg(0) and res(0) already forced in regs
Ilsl, Ilsr, Iasr: arg(1) already forced in regs *)
(arg, res)
| Iintop(Imul) | Iaddf | Isubf | Imulf | Idivf ->
(* First argument (= result) must be in register, second arg
can reside in the stack *)
if stackp arg.(0)
then (let r = self#makereg arg.(0) in ([|r; arg.(1)|], [|r|]))
else (arg, res)
| Ifloatofint | Iintoffloat ->
(* Result must be in register, but argument can be on stack *)
(arg, (if stackp res.(0) then [| self#makereg res.(0) |] else res))
| Iconst_int n ->
if n <= 0x7FFFFFFFn && n >= -0x80000000n
then (arg, res)
else super#reload_operation op arg res
| Iconst_symbol _ ->
if !Clflags.pic_code || !Clflags.dlcode || Arch.win64
then super#reload_operation op arg res
else (arg, res)
| _ -> (* Other operations: all args and results in registers *)
super#reload_operation op arg res
method! reload_test tst arg =
match tst with
Iinttest _ ->
(* One of the two arguments can reside on stack *)
if stackp arg.(0) && stackp arg.(1)
then [| self#makereg arg.(0); arg.(1) |]
else arg
| Ifloattest (CFlt | CFnlt | CFle | CFnle) ->
(* Cf. emit.mlp: we swap arguments in this case *)
(* First argument can be on stack, second must be in register *)
if stackp arg.(1)
then [| arg.(0); self#makereg arg.(1) |]
else arg
| Ifloattest (CFeq | CFneq | CFgt | CFngt | CFge | CFnge) ->
(* Second argument can be on stack, first must be in register *)
if stackp arg.(0)
then [| self#makereg arg.(0); arg.(1) |]
else arg
| _ ->
(* The argument(s) can be either in register or on stack *)
arg
end
let fundecl f =
(new reload)#fundecl f
|
