ocaml/asmcomp/power/scheduling.ml

66 lines
2.0 KiB
OCaml

(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* Automatique. Distributed only by permission. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Instruction scheduling for the Power PC *)
open Arch
open Mach
class scheduler = object
inherit Schedgen.scheduler_generic
(* Latencies (in cycles). Based roughly on the "common model". *)
method oper_latency = function
Ireload -> 2
| Iload(_, _) -> 2
| Iconst_float _ -> 2 (* turned into a load *)
| Iconst_symbol _ -> if toc then 2 (* turned into a load *) else 1
| Iintop Imul -> 9
| Iintop_imm(Imul, _) -> 5
| Iintop(Idiv | Imod) -> 36
| Iaddf | Isubf -> 4
| Imulf -> 5
| Idivf -> 33
| Ispecific(Imultaddf | Imultsubf) -> 5
| _ -> 1
method reload_retaddr_latency = 12
(* If we can have that many cycles between the reloadretaddr and the
return, we can expect that the blr branch will be completely folded. *)
(* Issue cycles. Rough approximations. *)
method oper_issue_cycles = function
Iconst_float _ | Iconst_symbol _ -> if toc then 1 else 2
| Iload(_, Ibased(_, _)) -> 2
| Istore(_, Ibased(_, _)) -> 2
| Ialloc _ -> 4
| Iintop(Imod) -> 40 (* assuming full stall *)
| Iintop(Icomp _) -> 4
| Iintop_imm(Idiv, _) -> 2
| Iintop_imm(Imod, _) -> 4
| Iintop_imm(Icomp _, _) -> 4
| Ifloatofint -> 9
| Iintoffloat -> 4
| _ -> 1
method reload_retaddr_issue_cycles = 3
(* load then stalling mtlr *)
end
let fundecl f = (new scheduler)#schedule_fundecl f