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;; ARM Cortex-A9 pipeline description

;; Copyright (C) 2008, 2009 Free Software Foundation, Inc.

;; Originally written by CodeSourcery for VFP.

;;

;; Integer core pipeline description contributed by ARM Ltd.

;;

;; 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

;; .

(define_automaton "cortex_a9")

;; The Cortex-A9 integer core is modelled as a dual issue pipeline that has

;; the following components.

;; 1. 1 Load Store Pipeline.

;; 2. P0 / main pipeline for data processing instructions.

;; 3. P1 / Dual pipeline for Data processing instructions.

;; 4. MAC pipeline for multiply as well as multiply

;;    and accumulate instructions.

;; 5. 1 VFP / Neon pipeline.

;; The Load/Store and VFP/Neon pipeline are multiplexed.

;; The P0 / main pipeline and M1 stage of the MAC pipeline are

;;   multiplexed.

;; The P1 / dual pipeline and M2 stage of the MAC pipeline are

;;   multiplexed.

;; There are only 4 register read ports and hence at any point of

;; time we can't have issue down the E1 and the E2 ports unless

;; of course there are bypass paths that get exercised.

;; Both P0 and P1 have 2 stages E1 and E2.

;; Data processing instructions issue to E1 or E2 depending on

;; whether they have an early shift or not.

(define_cpu_unit "cortex_a9_vfp, cortex_a9_ls" "cortex_a9")

(define_cpu_unit "cortex_a9_p0_e1, cortex_a9_p0_e2" "cortex_a9")

(define_cpu_unit "cortex_a9_p1_e1, cortex_a9_p1_e2" "cortex_a9")

(define_cpu_unit "cortex_a9_p0_wb, cortex_a9_p1_wb" "cortex_a9")

(define_cpu_unit "cortex_a9_mac_m1, cortex_a9_mac_m2" "cortex_a9")

(define_cpu_unit "cortex_a9_branch, cortex_a9_issue_branch" "cortex_a9")

(define_reservation "cortex_a9_p0_default" "cortex_a9_p0_e2, cortex_a9_p0_wb")

(define_reservation "cortex_a9_p1_default" "cortex_a9_p1_e2, cortex_a9_p1_wb")

(define_reservation "cortex_a9_p0_shift" "cortex_a9_p0_e1, cortex_a9_p0_default")

(define_reservation "cortex_a9_p1_shift" "cortex_a9_p1_e1, cortex_a9_p1_default")

(define_reservation "cortex_a9_multcycle1"

  "cortex_a9_p0_e2 + cortex_a9_mac_m1 + cortex_a9_mac_m2 + \

cortex_a9_p1_e2 + cortex_a9_p0_e1 + cortex_a9_p1_e1")

(define_reservation "cortex_a9_mult16"

  "cortex_a9_mac_m1, cortex_a9_mac_m2, cortex_a9_p0_wb")

(define_reservation "cortex_a9_mac16"

  "cortex_a9_multcycle1, cortex_a9_mac_m2, cortex_a9_p0_wb")

(define_reservation "cortex_a9_mult"

  "cortex_a9_mac_m1*2, cortex_a9_mac_m2, cortex_a9_p0_wb")

(define_reservation "cortex_a9_mac"

  "cortex_a9_multcycle1*2 ,cortex_a9_mac_m2, cortex_a9_p0_wb")

;; Issue at the same time along the load store pipeline and

;; the VFP / Neon pipeline is not possible.

;; FIXME:: At some point we need to model the issue

;; of the load store and the vfp being shared rather than anything else.

(exclusion_set "cortex_a9_ls" "cortex_a9_vfp")

;; Default data processing instruction without any shift

;; The only exception to this is the mov instruction

;; which can go down E2 without any problem.

(define_insn_reservation "cortex_a9_dp" 2

  (and (eq_attr "tune" "cortexa9")

       (ior (eq_attr "type" "alu")

            (and (eq_attr "type" "alu_shift_reg, alu_shift")

                 (eq_attr "insn" "mov"))))

  "cortex_a9_p0_default|cortex_a9_p1_default")

;; An instruction using the shifter will go down E1.

(define_insn_reservation "cortex_a9_dp_shift" 3

   (and (eq_attr "tune" "cortexa9")

        (and (eq_attr "type" "alu_shift_reg, alu_shift")

             (not (eq_attr "insn" "mov"))))

   "cortex_a9_p0_shift | cortex_a9_p1_shift")

;; Loads have a latency of 4 cycles.

;; We don't model autoincrement instructions. These

;; instructions use the load store pipeline and 1 of

;; the E2 units to write back the result of the increment.

(define_insn_reservation "cortex_a9_load1_2" 4

  (and (eq_attr "tune" "cortexa9")

       (eq_attr "type" "load1, load2, load_byte"))

  "cortex_a9_ls")

;; Loads multiples and store multiples can't be issued for 2 cycles in a

;; row. The description below assumes that addresses are 64 bit aligned.

;; If not, there is an extra cycle latency which is not modelled.

;; FIXME:: This bit might need to be reworked when we get to

;; tuning for the VFP because strictly speaking the ldm

;; is sent to the LSU unit as is and there is only an

;; issue restriction between the LSU and the VFP/ Neon unit.

(define_insn_reservation "cortex_a9_load3_4" 5

  (and (eq_attr "tune" "cortexa9")

       (eq_attr "type" "load3, load4"))

  "cortex_a9_ls, cortex_a9_ls")

(define_insn_reservation "cortex_a9_store1_2" 0

  (and (eq_attr "tune" "cortexa9")

       (eq_attr "type" "store1, store2"))

  "cortex_a9_ls")

;; Almost all our store multiples use an auto-increment

;; form. Don't issue back to back load and store multiples

;; because the load store unit will stall.

(define_insn_reservation "cortex_a9_store3_4" 0

  (and (eq_attr "tune" "cortexa9")

       (eq_attr "type" "store3, store4"))

  "cortex_a9_ls+(cortex_a9_p0_default | cortex_a9_p1_default), cortex_a9_ls")

;; We get 16*16 multiply / mac results in 3 cycles.

(define_insn_reservation "cortex_a9_mult16" 3

  (and (eq_attr "tune" "cortexa9")

       (eq_attr "insn" "smulxy"))

       "cortex_a9_mult16")

;; The 16*16 mac is slightly different that it

;; reserves M1 and M2 in the same cycle.

(define_insn_reservation "cortex_a9_mac16" 3

  (and (eq_attr "tune" "cortexa9")

       (eq_attr "insn" "smlaxy"))

  "cortex_a9_mac16")

(define_insn_reservation "cortex_a9_multiply" 4

  (and (eq_attr "tune" "cortexa9")

       (eq_attr "insn" "mul"))

       "cortex_a9_mult")

(define_insn_reservation "cortex_a9_mac" 4

  (and (eq_attr "tune" "cortexa9")

       (eq_attr "insn" "mla"))

       "cortex_a9_mac")

;; An instruction with a result in E2 can be forwarded

;; to E2 or E1 or M1 or the load store unit in the next cycle.

(define_bypass 1 "cortex_a9_dp"

                 "cortex_a9_dp_shift, cortex_a9_multiply,

 cortex_a9_load1_2, cortex_a9_dp, cortex_a9_store1_2,

 cortex_a9_mult16, cortex_a9_mac16, cortex_a9_mac, cortex_a9_store3_4, cortex_a9_load3_4")

(define_bypass 2 "cortex_a9_dp_shift"

                 "cortex_a9_dp_shift, cortex_a9_multiply,

 cortex_a9_load1_2, cortex_a9_dp, cortex_a9_store1_2,

 cortex_a9_mult16, cortex_a9_mac16, cortex_a9_mac, cortex_a9_store3_4, cortex_a9_load3_4")

;; An instruction in the load store pipeline can provide

;; read access to a DP instruction in the P0 default pipeline

;; before the writeback stage.

(define_bypass 3 "cortex_a9_load1_2" "cortex_a9_dp, cortex_a9_load1_2,

cortex_a9_store3_4, cortex_a9_store1_2")

(define_bypass 4 "cortex_a9_load3_4" "cortex_a9_dp, cortex_a9_load1_2,

cortex_a9_store3_4, cortex_a9_store1_2,  cortex_a9_load3_4")

;; Calls and branches.

;; Branch instructions

(define_insn_reservation "cortex_a9_branch" 0

  (and (eq_attr "tune" "cortexa9")

       (eq_attr "type" "branch"))

  "cortex_a9_branch")

;; Call latencies are essentially 0 but make sure

;; dual issue doesn't happen i.e the next instruction

;; starts at the next cycle.

(define_insn_reservation "cortex_a9_call"  0

  (and (eq_attr "tune" "cortexa9")

       (eq_attr "type" "call"))

  "cortex_a9_issue_branch + cortex_a9_multcycle1 + cortex_a9_ls + cortex_a9_vfp")

;; Pipelining for VFP instructions.

(define_insn_reservation "cortex_a9_ffarith" 1

 (and (eq_attr "tune" "cortexa9")

      (eq_attr "type" "fcpys,ffariths,ffarithd,fcmps,fcmpd,fconsts,fconstd"))

 "cortex_a9_vfp")

(define_insn_reservation "cortex_a9_fadd" 4

 (and (eq_attr "tune" "cortexa9")

      (eq_attr "type" "fadds,faddd,f_cvt"))

 "cortex_a9_vfp")

(define_insn_reservation "cortex_a9_fmuls" 5

 (and (eq_attr "tune" "cortexa9")

      (eq_attr "type" "fmuls"))

 "cortex_a9_vfp")

(define_insn_reservation "cortex_a9_fmuld" 6

 (and (eq_attr "tune" "cortexa9")

      (eq_attr "type" "fmuld"))

 "cortex_a9_vfp*2")

(define_insn_reservation "cortex_a9_fmacs" 8

 (and (eq_attr "tune" "cortexa9")

      (eq_attr "type" "fmacs"))

 "cortex_a9_vfp")

(define_insn_reservation "cortex_a9_fmacd" 8

 (and (eq_attr "tune" "cortexa9")

      (eq_attr "type" "fmacd"))

 "cortex_a9_vfp*2")

(define_insn_reservation "cortex_a9_fdivs" 15

 (and (eq_attr "tune" "cortexa9")

      (eq_attr "type" "fdivs"))

 "cortex_a9_vfp*10")

(define_insn_reservation "cortex_a9_fdivd" 25

 (and (eq_attr "tune" "cortexa9")

      (eq_attr "type" "fdivd"))

 "cortex_a9_vfp*20")