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;; ARM Cortex-R4 scheduling description.
;; Copyright (C) 2007, 2008 Free Software Foundation, Inc.
;; Contributed by CodeSourcery.
;; 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
;; <http://www.gnu.org/licenses/>.
(define_automaton "cortex_r4")
;; We approximate the dual-issue constraints of this core using four
;; "issue units" and a reservation matrix as follows. The numbers indicate
;; the instruction groups' preferences in order. Multiple entries for
;; the same numbered preference indicate units that must be reserved
;; together.
;;
;; Issue unit: A B C ALU
;;
;; ALU w/o reg shift 1st 2nd 1st and 2nd
;; ALU w/ reg shift 1st 2nd 2nd 1st and 2nd
;; Moves 1st 2nd 2nd
;; Multiplication 1st 1st
;; Division 1st 1st
;; Load/store single 1st 1st
;; Other load/store 1st 1st
;; Branches 1st
(define_cpu_unit "cortex_r4_issue_a" "cortex_r4")
(define_cpu_unit "cortex_r4_issue_b" "cortex_r4")
(define_cpu_unit "cortex_r4_issue_c" "cortex_r4")
(define_cpu_unit "cortex_r4_issue_alu" "cortex_r4")
(define_reservation "cortex_r4_alu"
"(cortex_r4_issue_a+cortex_r4_issue_alu)|\
(cortex_r4_issue_b+cortex_r4_issue_alu)")
(define_reservation "cortex_r4_alu_shift_reg"
"(cortex_r4_issue_a+cortex_r4_issue_alu)|\
(cortex_r4_issue_b+cortex_r4_issue_c+\
cortex_r4_issue_alu)")
(define_reservation "cortex_r4_mov"
"cortex_r4_issue_a|(cortex_r4_issue_b+\
cortex_r4_issue_alu)")
(define_reservation "cortex_r4_mul" "cortex_r4_issue_a+cortex_r4_issue_alu")
(define_reservation "cortex_r4_mul_2"
"(cortex_r4_issue_a+cortex_r4_issue_alu)*2")
;; Division instructions execute out-of-order with respect to the
;; rest of the pipeline and only require reservations on their first and
;; final cycles.
(define_reservation "cortex_r4_div_9"
"cortex_r4_issue_a+cortex_r4_issue_alu,\
nothing*7,\
cortex_r4_issue_a+cortex_r4_issue_alu")
(define_reservation "cortex_r4_div_10"
"cortex_r4_issue_a+cortex_r4_issue_alu,\
nothing*8,\
cortex_r4_issue_a+cortex_r4_issue_alu")
(define_reservation "cortex_r4_load_store"
"cortex_r4_issue_a+cortex_r4_issue_c")
(define_reservation "cortex_r4_load_store_2"
"(cortex_r4_issue_a+cortex_r4_issue_b)*2")
(define_reservation "cortex_r4_branch" "cortex_r4_issue_b")
;; We assume that all instructions are unconditional.
;; Data processing instructions. Moves without shifts are kept separate
;; for the purposes of the dual-issue constraints above.
(define_insn_reservation "cortex_r4_alu" 2
(and (eq_attr "tune" "cortexr4")
(and (eq_attr "type" "alu")
(not (eq_attr "insn" "mov"))))
"cortex_r4_alu")
(define_insn_reservation "cortex_r4_mov" 2
(and (eq_attr "tune" "cortexr4")
(and (eq_attr "type" "alu")
(eq_attr "insn" "mov")))
"cortex_r4_mov")
(define_insn_reservation "cortex_r4_alu_shift" 2
(and (eq_attr "tune" "cortexr4")
(eq_attr "type" "alu_shift"))
"cortex_r4_alu")
(define_insn_reservation "cortex_r4_alu_shift_reg" 2
(and (eq_attr "tune" "cortexr4")
(eq_attr "type" "alu_shift_reg"))
"cortex_r4_alu_shift_reg")
;; An ALU instruction followed by an ALU instruction with no early dep.
(define_bypass 1 "cortex_r4_alu,cortex_r4_alu_shift,cortex_r4_alu_shift_reg,\
cortex_r4_mov"
"cortex_r4_alu")
(define_bypass 1 "cortex_r4_alu,cortex_r4_alu_shift,cortex_r4_alu_shift_reg,\
cortex_r4_mov"
"cortex_r4_alu_shift"
"arm_no_early_alu_shift_dep")
(define_bypass 1 "cortex_r4_alu,cortex_r4_alu_shift,cortex_r4_alu_shift_reg,\
cortex_r4_mov"
"cortex_r4_alu_shift_reg"
"arm_no_early_alu_shift_value_dep")
;; In terms of availabilities, a consumer mov could theoretically be
;; issued together with a producer ALU instruction, without stalls.
;; In practice this cannot happen because mov;add (in that order) is not
;; eligible for dual issue and furthermore dual issue is not permitted
;; when a dependency is involved. We therefore note it as latency one.
;; A mov followed by another of the same is also latency one.
(define_bypass 1 "cortex_r4_alu,cortex_r4_alu_shift,cortex_r4_alu_shift_reg,\
cortex_r4_mov"
"cortex_r4_mov")
;; qadd, qdadd, qsub and qdsub are not currently emitted, and neither are
;; media data processing instructions nor sad instructions.
;; Multiplication instructions.
(define_insn_reservation "cortex_r4_mul_4" 4
(and (eq_attr "tune" "cortexr4")
(eq_attr "insn" "mul,smmul"))
"cortex_r4_mul_2")
(define_insn_reservation "cortex_r4_mul_3" 3
(and (eq_attr "tune" "cortexr4")
(eq_attr "insn" "smulxy,smulwy,smuad,smusd"))
"cortex_r4_mul")
(define_insn_reservation "cortex_r4_mla_4" 4
(and (eq_attr "tune" "cortexr4")
(eq_attr "insn" "mla,smmla"))
"cortex_r4_mul_2")
(define_insn_reservation "cortex_r4_mla_3" 3
(and (eq_attr "tune" "cortexr4")
(eq_attr "insn" "smlaxy,smlawy,smlad,smlsd"))
"cortex_r4_mul")
(define_insn_reservation "cortex_r4_smlald" 3
(and (eq_attr "tune" "cortexr4")
(eq_attr "insn" "smlald,smlsld"))
"cortex_r4_mul")
(define_insn_reservation "cortex_r4_mull" 4
(and (eq_attr "tune" "cortexr4")
(eq_attr "insn" "smull,umull,umlal,umaal"))
"cortex_r4_mul_2")
;; A multiply or an MLA with a single-register result, followed by an
;; MLA with an accumulator dependency, has its result forwarded.
(define_bypass 2 "cortex_r4_mul_3,cortex_r4_mla_3"
"cortex_r4_mla_3,cortex_r4_mla_4"
"arm_mac_accumulator_is_mul_result")
(define_bypass 3 "cortex_r4_mul_4,cortex_r4_mla_4"
"cortex_r4_mla_3,cortex_r4_mla_4"
"arm_mac_accumulator_is_mul_result")
;; A multiply followed by an ALU instruction needing the multiply
;; result only at ALU has lower latency than one needing it at Shift.
(define_bypass 2 "cortex_r4_mul_3,cortex_r4_mla_3,cortex_r4_smlald"
"cortex_r4_alu")
(define_bypass 2 "cortex_r4_mul_3,cortex_r4_mla_3,cortex_r4_smlald"
"cortex_r4_alu_shift"
"arm_no_early_alu_shift_dep")
(define_bypass 2 "cortex_r4_mul_3,cortex_r4_mla_3,cortex_r4_smlald"
"cortex_r4_alu_shift_reg"
"arm_no_early_alu_shift_value_dep")
(define_bypass 3 "cortex_r4_mul_4,cortex_r4_mla_4,cortex_r4_mull"
"cortex_r4_alu")
(define_bypass 3 "cortex_r4_mul_4,cortex_r4_mla_4,cortex_r4_mull"
"cortex_r4_alu_shift"
"arm_no_early_alu_shift_dep")
(define_bypass 3 "cortex_r4_mul_4,cortex_r4_mla_4,cortex_r4_mull"
"cortex_r4_alu_shift_reg"
"arm_no_early_alu_shift_value_dep")
;; A multiply followed by a mov has one cycle lower latency again.
(define_bypass 1 "cortex_r4_mul_3,cortex_r4_mla_3,cortex_r4_smlald"
"cortex_r4_mov")
(define_bypass 2 "cortex_r4_mul_4,cortex_r4_mla_4,cortex_r4_mull"
"cortex_r4_mov")
;; We guess that division of A/B using sdiv or udiv, on average,
;; is performed with B having ten more leading zeros than A.
;; This gives a latency of nine for udiv and ten for sdiv.
(define_insn_reservation "cortex_r4_udiv" 9
(and (eq_attr "tune" "cortexr4")
(eq_attr "insn" "udiv"))
"cortex_r4_div_9")
(define_insn_reservation "cortex_r4_sdiv" 10
(and (eq_attr "tune" "cortexr4")
(eq_attr "insn" "sdiv"))
"cortex_r4_div_10")
;; Branches. We assume correct prediction.
(define_insn_reservation "cortex_r4_branch" 0
(and (eq_attr "tune" "cortexr4")
(eq_attr "type" "branch"))
"cortex_r4_branch")
;; Call latencies are not predictable. A semi-arbitrary very large
;; number is used as "positive infinity" so that everything should be
;; finished by the time of return.
(define_insn_reservation "cortex_r4_call" 32
(and (eq_attr "tune" "cortexr4")
(eq_attr "type" "call"))
"nothing")
;; Status register access instructions are not currently emitted.
;; Load instructions.
;; We do not model the "addr_md_3cycle" cases and assume that
;; accesses following are correctly aligned.
(define_insn_reservation "cortex_r4_load_1_2" 3
(and (eq_attr "tune" "cortexr4")
(eq_attr "type" "load1,load2"))
"cortex_r4_load_store")
(define_insn_reservation "cortex_r4_load_3_4" 4
(and (eq_attr "tune" "cortexr4")
(eq_attr "type" "load3,load4"))
"cortex_r4_load_store_2")
;; If a producing load is followed by an instruction consuming only
;; as a Normal Reg, there is one fewer cycle of latency.
(define_bypass 2 "cortex_r4_load_1_2"
"cortex_r4_alu")
(define_bypass 2 "cortex_r4_load_1_2"
"cortex_r4_alu_shift"
"arm_no_early_alu_shift_dep")
(define_bypass 2 "cortex_r4_load_1_2"
"cortex_r4_alu_shift_reg"
"arm_no_early_alu_shift_value_dep")
(define_bypass 3 "cortex_r4_load_3_4"
"cortex_r4_alu")
(define_bypass 3 "cortex_r4_load_3_4"
"cortex_r4_alu_shift"
"arm_no_early_alu_shift_dep")
(define_bypass 3 "cortex_r4_load_3_4"
"cortex_r4_alu_shift_reg"
"arm_no_early_alu_shift_value_dep")
;; If a producing load is followed by an instruction consuming only
;; as a Late Reg, there are two fewer cycles of latency. Such consumer
;; instructions are moves and stores.
(define_bypass 1 "cortex_r4_load_1_2"
"cortex_r4_mov,cortex_r4_store_1_2,cortex_r4_store_3_4")
(define_bypass 2 "cortex_r4_load_3_4"
"cortex_r4_mov,cortex_r4_store_1_2,cortex_r4_store_3_4")
;; If a producer's result is required as the base or offset of a load,
;; there is an extra cycle latency.
(define_bypass 3 "cortex_r4_alu,cortex_r4_mov,cortex_r4_alu_shift,\
cortex_r4_alu_shift_reg"
"cortex_r4_load_1_2,cortex_r4_load_3_4")
(define_bypass 4 "cortex_r4_mul_3,cortex_r4_mla_3,cortex_r4_smlald"
"cortex_r4_load_1_2,cortex_r4_load_3_4")
(define_bypass 5 "cortex_r4_mul_4,cortex_r4_mla_4,cortex_r4_mull"
"cortex_r4_load_1_2,cortex_r4_load_3_4")
;; Store instructions.
(define_insn_reservation "cortex_r4_store_1_2" 0
(and (eq_attr "tune" "cortexr4")
(eq_attr "type" "store1,store2"))
"cortex_r4_load_store")
(define_insn_reservation "cortex_r4_store_3_4" 0
(and (eq_attr "tune" "cortexr4")
(eq_attr "type" "store3,store4"))
"cortex_r4_load_store_2")
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