ocaml/asmcomp/sparc/scheduling.ml

66 lines
2.2 KiB
OCaml

(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* en Automatique. All rights reserved. This file is distributed *)
(* under the terms of the Q Public License version 1.0. *)
(* *)
(***********************************************************************)
(* $Id$ *)
open Cmm
open Mach
(* Instruction scheduling for the Sparc *)
class scheduler = object
inherit Schedgen.scheduler_generic
(* Latencies (in cycles). *)
(* UltraSPARC issues two integer operations, plus a single load or store,
per cycle. At most one of the integer instructions may be a shift.
Most integer operations have one cycle latency. Unsigned loads take
two cycles. Signed loads take three cycles. Conditional moves have
two cycle latency and may not issue in the same cycle as any other
instruction. Floating point issue rules are complicated, but in
general independent add and multiply can dual issue with four cycle
latency. *)
method oper_latency = function
Ireload -> 2
| Iload((Byte_signed|Sixteen_signed|Thirtytwo_signed), _) -> 3
| Iload(_, _) -> 2
| Iconst_float _ -> 2 (* turned into a load *)
| Inegf | Iabsf | Iaddf | Isubf | Imulf -> 4
| Idivf -> 15
| _ -> 1
(* Issue cycles. Rough approximations. *)
method oper_issue_cycles = function
Iconst_float _ -> 2
| Iconst_symbol _ -> 2
| Ialloc _ -> 6
| Iintop(Icomp _) -> 4
| Iintop(Icheckbound) -> 2
| Iintop_imm(Idiv, _) -> 5
| Iintop_imm(Imod, _) -> 5
| Iintop_imm(Icomp _, _) -> 4
| Iintop_imm(Icheckbound, _) -> 2
| Inegf -> 2
| Iabsf -> 2
| Ifloatofint -> 6
| Iintoffloat -> 6
| _ -> 1
end
let fundecl f = (new scheduler)#schedule_fundecl f