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;; DFA scheduling description for EPIPHANY

;; Copyright (C) 2004, 2006, 2007, 2009 Free Software Foundation, Inc.

;; Contributed by Embecosm on behalf of Adapteva, Inc.

;; This file is part of GCC.

;; GCC is free software; you can redistribute it and/or modify

;; it under the terms of the GNU General Public License as published by

;; the Free Software Foundation; either version 3, or (at your option)

;; any later version.

;; GCC is distributed in the hope that it will be useful,

;; but WITHOUT ANY WARRANTY; without even the implied warranty of

;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License

;; along with GCC; see the file COPYING3.  If not see

;; .

;; Two automata are defined to reduce number of states

;; which a single large automaton will have. (Factoring)

(define_automaton "inst_pipeline,fpu_pipe")

;; This unit is basically the decode unit of the processor.

;; Since epiphany is a dual issue machine, it is as if there are two

;; units so that any insn can be processed by either one

;; of the decoding unit.

(define_cpu_unit "pipe_01,pipe_02" "inst_pipeline")

;; The fixed point arithmetic unit.

(define_cpu_unit  "int" "inst_pipeline")

;; The floating point unit.

(define_cpu_unit "F0" "fpu_pipe")

;; ----------------------------------------------------

;; This reservation is to simplify the dual issue description.

(define_reservation  "issue"  "pipe_01|pipe_02")

;; This is to express instructions that cannot be paired.

(define_reservation  "d_lock" "pipe_01+pipe_02")

;; We don't model all pipeline stages; we model the issue stage

;; inasmuch as we allow only two instructions to issue simultaneously,

;; and flow instructions prevent any simultaneous issue of another instruction.

;; (This uses pipe_01 and pipe_02).

;; Double issue of 'other' insns is prevented by using the int unit in the

;; E1 stage.

;; Double issue of float instructions is prevented by using F0 in the E1 stage.

(define_insn_reservation "simple_arith" 2

  (and (eq_attr "pipe_model" "epiphany")

       (eq_attr "type" "move,cmove,compare,shift,misc,mul")

       (eq_attr "length" "4"))

  "issue,int")

; anything but fp / fp_int has a bypass

(define_bypass 1 "simple_arith" "simple_arith,simple_arith_2,simple_arith_4,load,store,branch,call,flow")

(define_insn_reservation "simple_arith_2" 2

  (and (eq_attr "pipe_model" "epiphany")

       (eq_attr "type" "move,cmove,compare,shift,misc,mul")

       (eq_attr "length" "8"))

  "issue,issue+int,int")

(define_insn_reservation "simple_arith_4" 4

  (and (eq_attr "pipe_model" "epiphany")

       (eq_attr "type" "move,compare,shift,misc,mul")

       (eq_attr "length" "12,16,20,24"))

  "issue,issue+int,issue+int,issue+int,int")

;; Loads have a latency of two.

;; Note that we fix up the latency of post_modify in epiphany.c:epiphany_adjust_cost

(define_insn_reservation "load" 3

  (and (eq_attr "pipe_model" "epiphany")

       (eq_attr "type" "load"))

  "issue,int")

; anything but fp / fp_int has a bypass

(define_bypass 2 "load" "simple_arith,simple_arith_2,simple_arith_4,load,store,branch,call,flow")

(define_insn_reservation "store" 1

  (and (eq_attr "pipe_model" "epiphany")

       (eq_attr "type" "store"))

  "issue,int")

;; Branch

;; Latency when taken:  3

;; Issue Rate:  1

;; The latency is 1 when the branch is not taken.

;; We can't really do much with the latency, even if we could express it,

;; but the pairing restrictions are useful to take into account.

(define_insn_reservation "branch"  1

  (and (eq_attr "pipe_model" "epiphany")

       (eq_attr "type" "branch,uncond_branch"))

  "d_lock")

;; calls introduce a longisch delay that is likely to flush the pipelines

;; of the caller's instructions.  Both the call instruction itself and

;; the rts at the end of the call / sfunc incurs a three cycle penalty,

;; thus also isolating the scheduling of caller and callee.

(define_insn_reservation "call" 8

  (and (eq_attr "pipe_model" "epiphany")

       (eq_attr "type" "call,sfunc,fp_sfunc"))

  "d_lock*8")

(define_insn_reservation "flow" 1

  (and (eq_attr "pipe_model" "epiphany")

       (eq_attr "type" "flow"))

  "d_lock")

(define_insn_reservation "fp_arith_trunc"  3

  (and (eq_attr "pipe_model" "epiphany")

       (and (eq_attr "type" "fp,fp_int")

            (eq_attr "rounding" "trunc")))

  "issue,F0")

(define_insn_reservation "fp_arith_nearest"  5

  (and (eq_attr "pipe_model" "epiphany")

       (and (eq_attr "type" "fp,fp_int")

            (eq_attr "rounding" "nearest")))

  "issue,F0")

(define_bypass 2 "fp_arith_trunc" "store")

(define_bypass 4 "fp_arith_nearest" "store")