;; Faraday FA626TE Pipeline Description ;; Copyright (C) 2010 Free Software Foundation, Inc. ;; Written by Mingfeng Wu, 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 ;; . */ ;; These descriptions are based on the information contained in the ;; FMP626 Core Design Note, Copyright (c) 2010 Faraday Technology Corp. ;; Pipeline architecture ;; S E M W(Q1) Q2 ;; ___________________________________________ ;; shifter alu ;; mul1 mul2 mul3 ;; ld/st1 ld/st2 ld/st3 ld/st4 ld/st5 ;; This automaton provides a pipeline description for the Faraday ;; FMP626 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 "fmp626") ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; 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. (define_cpu_unit "fmp626_core" "fmp626") ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; 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 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 "mp626_alu_op" 1 (and (eq_attr "tune" "fmp626") (eq_attr "type" "alu")) "fmp626_core") (define_insn_reservation "mp626_alu_shift_op" 2 (and (eq_attr "tune" "fmp626") (eq_attr "type" "alu_shift,alu_shift_reg")) "fmp626_core") ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Multiplication Instructions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; (define_insn_reservation "mp626_mult1" 2 (and (eq_attr "tune" "fmp626") (eq_attr "insn" "smulwy,smlawy,smulxy,smlaxy")) "fmp626_core") (define_insn_reservation "mp626_mult2" 2 (and (eq_attr "tune" "fmp626") (eq_attr "insn" "mul,mla")) "fmp626_core") (define_insn_reservation "mp626_mult3" 3 (and (eq_attr "tune" "fmp626") (eq_attr "insn" "muls,mlas,smull,smlal,umull,umlal,smlalxy,smlawx")) "fmp626_core*2") (define_insn_reservation "mp626_mult4" 4 (and (eq_attr "tune" "fmp626") (eq_attr "insn" "smulls,smlals,umulls,umlals")) "fmp626_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 "mp626_load1_op" 5 (and (eq_attr "tune" "fmp626") (eq_attr "type" "load1,load_byte")) "fmp626_core") (define_insn_reservation "mp626_load2_op" 6 (and (eq_attr "tune" "fmp626") (eq_attr "type" "load2,load3")) "fmp626_core*2") (define_insn_reservation "mp626_load3_op" 7 (and (eq_attr "tune" "fmp626") (eq_attr "type" "load4")) "fmp626_core*3") (define_insn_reservation "mp626_store1_op" 0 (and (eq_attr "tune" "fmp626") (eq_attr "type" "store1")) "fmp626_core") (define_insn_reservation "mp626_store2_op" 1 (and (eq_attr "tune" "fmp626") (eq_attr "type" "store2,store3")) "fmp626_core*2") (define_insn_reservation "mp626_store3_op" 2 (and (eq_attr "tune" "fmp626") (eq_attr "type" "store4")) "fmp626_core*3") (define_bypass 1 "mp626_load1_op,mp626_load2_op,mp626_load3_op" "mp626_store1_op,mp626_store2_op,mp626_store3_op" "arm_no_early_store_addr_dep") (define_bypass 1 "mp626_alu_op,mp626_alu_shift_op,mp626_mult1,mp626_mult2,\ mp626_mult3,mp626_mult4" "mp626_store1_op" "arm_no_early_store_addr_dep") (define_bypass 1 "mp626_alu_shift_op" "mp626_alu_op") (define_bypass 1 "mp626_alu_shift_op" "mp626_alu_shift_op" "arm_no_early_alu_shift_dep") (define_bypass 1 "mp626_mult1,mp626_mult2" "mp626_alu_shift_op" "arm_no_early_alu_shift_dep") (define_bypass 2 "mp626_mult3" "mp626_alu_shift_op" "arm_no_early_alu_shift_dep") (define_bypass 3 "mp626_mult4" "mp626_alu_shift_op" "arm_no_early_alu_shift_dep") (define_bypass 1 "mp626_mult1,mp626_mult2" "mp626_alu_op") (define_bypass 2 "mp626_mult3" "mp626_alu_op") (define_bypass 3 "mp626_mult4" "mp626_alu_op") (define_bypass 4 "mp626_load1_op" "mp626_alu_op") (define_bypass 5 "mp626_load2_op" "mp626_alu_op") (define_bypass 6 "mp626_load3_op" "mp626_alu_op") ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Branch and Call Instructions ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Branch instructions are difficult to model accurately. The FMP626 ;; 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 "mp626_branch_op" 0 (and (eq_attr "tune" "fmp626") (eq_attr "type" "branch")) "fmp626_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 "mp626_call_op" 1 (and (eq_attr "tune" "fmp626") (eq_attr "type" "call")) "fmp626_core")