gcc/config/arm/fa626te.md

;; Faraday FA626TE Pipeline Description ;; Copyright (C) 2010-2021 Free Software Foundation, Inc. ;; Written by I-Jui Sung, based on ARM926EJ-S Pipeline Description. ;; ;; 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/. */

;; Modeled pipeline characteristics: ;; ALU -> simple address LDR/STR: latency = 2 (available after 2 cycles). ;; ALU -> shifted address LDR/STR: latency = 3. ;; ( extra 1 cycle unavoidable stall). ;; ALU -> other use: latency = 2 (available after 2 cycles). ;; LD -> simple address LDR/STR: latency = 3 (available after 3 cycles). ;; LD -> shifted address LDR/STR: latency = 4 ;; ( extra 1 cycle unavoidable stall). ;; LD -> any other use: latency = 3 (available after 3 cycles).

;; This automaton provides a pipeline description for the Faraday ;; FA626TE core. ;; ;; The model given here assumes that the condition for all conditional ;; instructions is “true”, i.e., that all of the instructions are ;; actually executed.

(define_automaton “fa626te”)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Pipelines ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; There is a single pipeline ;; ;; The ALU pipeline has fetch, decode, execute, memory, and ;; write stages. We only need to model the execute, memory and write ;; stages.

;; S E M W

(define_cpu_unit “fa626te_core” “fa626te”)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; ALU Instructions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; ALU instructions require two cycles to execute, and use the ALU ;; pipeline in each of the three stages. The results are available ;; after the execute stage has finished. ;; ;; If the destination register is the PC, the pipelines are stalled ;; for several cycles. That case is not modeled here.

;; ALU operations (define_insn_reservation “626te_alu_op” 1 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “alu_imm,alus_imm,logic_imm,logics_imm,
alu_sreg,alus_sreg,logic_reg,logics_reg,
adc_imm,adcs_imm,adc_reg,adcs_reg,
adr,bfm,rev,
shift_imm,shift_reg,
mov_imm,mov_reg,mvn_imm,mvn_reg,
mrs,multiple”)) “fa626te_core”)

(define_insn_reservation “626te_alu_shift_op” 2 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “extend,
alu_shift_imm_lsl_1to4,alu_shift_imm_other,alus_shift_imm,
logic_shift_imm,logics_shift_imm,
alu_shift_reg,alus_shift_reg,
logic_shift_reg,logics_shift_reg,
mov_shift,mov_shift_reg,
mvn_shift,mvn_shift_reg”)) “fa626te_core”)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Multiplication Instructions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(define_insn_reservation “626te_mult1” 2 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “smulwy,smlawy,smulxy,smlaxy”)) “fa626te_core”)

(define_insn_reservation “626te_mult2” 2 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “mul,mla”)) “fa626te_core”)

(define_insn_reservation “626te_mult3” 3 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “muls,mlas,smull,smlal,umull,umlal,smlalxy,smlawx”)) “fa626te_core*2”)

(define_insn_reservation “626te_mult4” 4 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “smulls,smlals,umulls,umlals”)) “fa626te_core*3”)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Load/Store Instructions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; The models for load/store instructions do not accurately describe ;; the difference between operations with a base register writeback ;; (such as “ldm!”). These models assume that all memory references ;; hit in dcache.

(define_insn_reservation “626te_load1_op” 3 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “load_4,load_byte”)) “fa626te_core”)

(define_insn_reservation “626te_load2_op” 4 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “load_8,load_12”)) “fa626te_core*2”)

(define_insn_reservation “626te_load3_op” 5 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “load_16”)) “fa626te_core*3”)

(define_insn_reservation “626te_store1_op” 0 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “store_4”)) “fa626te_core”)

(define_insn_reservation “626te_store2_op” 1 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “store_8,store_12”)) “fa626te_core*2”)

(define_insn_reservation “626te_store3_op” 2 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “store_16”)) “fa626te_core*3”)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Branch and Call Instructions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; Branch instructions are difficult to model accurately. The FA626TE ;; core can predict most branches. If the branch is predicted ;; correctly, and predicted early enough, the branch can be completely ;; eliminated from the instruction stream. Some branches can ;; therefore appear to require zero cycle to execute. We assume that ;; all branches are predicted correctly, and that the latency is ;; therefore the minimum value.

(define_insn_reservation “626te_branch_op” 0 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “branch”)) “fa626te_core”)

;; The latency for a call is actually the latency when the result is available. ;; i.e. R0 ready for int return value. (define_insn_reservation “626te_call_op” 1 (and (eq_attr “tune” “fa626,fa626te”) (eq_attr “type” “call”)) “fa626te_core”)