1 ;; Faraday FA626TE Pipeline Description
2 ;; Copyright (C) 2010 Free Software Foundation, Inc.
3 ;; Written by Mingfeng Wu, based on ARM926EJ-S Pipeline Description.
5 ;; This file is part of GCC.
7 ;; GCC is free software; you can redistribute it and/or modify it under
8 ;; the terms of the GNU General Public License as published by the Free
9 ;; Software Foundation; either version 3, or (at your option) any later
12 ;; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 ;; WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 ;; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 ;; You should have received a copy of the GNU General Public License
18 ;; along with GCC; see the file COPYING3. If not see
19 ;; <http://www.gnu.org/licenses/>. */
21 ;; These descriptions are based on the information contained in the
22 ;; FMP626 Core Design Note, Copyright (c) 2010 Faraday Technology Corp.
24 ;; Pipeline architecture
26 ;; ___________________________________________
29 ;; ld/st1 ld/st2 ld/st3 ld/st4 ld/st5
31 ;; This automaton provides a pipeline description for the Faraday
34 ;; The model given here assumes that the condition for all conditional
35 ;; instructions is "true", i.e., that all of the instructions are
38 (define_automaton "fmp626")
40 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
42 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
44 ;; There is a single pipeline
46 ;; The ALU pipeline has fetch, decode, execute, memory, and
47 ;; write stages. We only need to model the execute, memory and write
50 (define_cpu_unit "fmp626_core" "fmp626")
52 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
54 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
56 ;; ALU instructions require two cycles to execute, and use the ALU
57 ;; pipeline in each of the three stages. The results are available
58 ;; after the execute stage stage has finished.
60 ;; If the destination register is the PC, the pipelines are stalled
61 ;; for several cycles. That case is not modeled here.
64 (define_insn_reservation "mp626_alu_op" 1
65 (and (eq_attr "tune" "fmp626")
66 (eq_attr "type" "alu"))
69 (define_insn_reservation "mp626_alu_shift_op" 2
70 (and (eq_attr "tune" "fmp626")
71 (eq_attr "type" "alu_shift,alu_shift_reg"))
74 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
75 ;; Multiplication Instructions
76 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
78 (define_insn_reservation "mp626_mult1" 2
79 (and (eq_attr "tune" "fmp626")
80 (eq_attr "insn" "smulwy,smlawy,smulxy,smlaxy"))
83 (define_insn_reservation "mp626_mult2" 2
84 (and (eq_attr "tune" "fmp626")
85 (eq_attr "insn" "mul,mla"))
88 (define_insn_reservation "mp626_mult3" 3
89 (and (eq_attr "tune" "fmp626")
90 (eq_attr "insn" "muls,mlas,smull,smlal,umull,umlal,smlalxy,smlawx"))
93 (define_insn_reservation "mp626_mult4" 4
94 (and (eq_attr "tune" "fmp626")
95 (eq_attr "insn" "smulls,smlals,umulls,umlals"))
98 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
99 ;; Load/Store Instructions
100 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
102 ;; The models for load/store instructions do not accurately describe
103 ;; the difference between operations with a base register writeback
104 ;; (such as "ldm!"). These models assume that all memory references
107 (define_insn_reservation "mp626_load1_op" 5
108 (and (eq_attr "tune" "fmp626")
109 (eq_attr "type" "load1,load_byte"))
112 (define_insn_reservation "mp626_load2_op" 6
113 (and (eq_attr "tune" "fmp626")
114 (eq_attr "type" "load2,load3"))
117 (define_insn_reservation "mp626_load3_op" 7
118 (and (eq_attr "tune" "fmp626")
119 (eq_attr "type" "load4"))
122 (define_insn_reservation "mp626_store1_op" 0
123 (and (eq_attr "tune" "fmp626")
124 (eq_attr "type" "store1"))
127 (define_insn_reservation "mp626_store2_op" 1
128 (and (eq_attr "tune" "fmp626")
129 (eq_attr "type" "store2,store3"))
132 (define_insn_reservation "mp626_store3_op" 2
133 (and (eq_attr "tune" "fmp626")
134 (eq_attr "type" "store4"))
137 (define_bypass 1 "mp626_load1_op,mp626_load2_op,mp626_load3_op"
138 "mp626_store1_op,mp626_store2_op,mp626_store3_op"
139 "arm_no_early_store_addr_dep")
140 (define_bypass 1 "mp626_alu_op,mp626_alu_shift_op,mp626_mult1,mp626_mult2,\
141 mp626_mult3,mp626_mult4" "mp626_store1_op"
142 "arm_no_early_store_addr_dep")
143 (define_bypass 1 "mp626_alu_shift_op" "mp626_alu_op")
144 (define_bypass 1 "mp626_alu_shift_op" "mp626_alu_shift_op"
145 "arm_no_early_alu_shift_dep")
146 (define_bypass 1 "mp626_mult1,mp626_mult2" "mp626_alu_shift_op"
147 "arm_no_early_alu_shift_dep")
148 (define_bypass 2 "mp626_mult3" "mp626_alu_shift_op"
149 "arm_no_early_alu_shift_dep")
150 (define_bypass 3 "mp626_mult4" "mp626_alu_shift_op"
151 "arm_no_early_alu_shift_dep")
152 (define_bypass 1 "mp626_mult1,mp626_mult2" "mp626_alu_op")
153 (define_bypass 2 "mp626_mult3" "mp626_alu_op")
154 (define_bypass 3 "mp626_mult4" "mp626_alu_op")
155 (define_bypass 4 "mp626_load1_op" "mp626_alu_op")
156 (define_bypass 5 "mp626_load2_op" "mp626_alu_op")
157 (define_bypass 6 "mp626_load3_op" "mp626_alu_op")
159 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
160 ;; Branch and Call Instructions
161 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
163 ;; Branch instructions are difficult to model accurately. The FMP626
164 ;; core can predict most branches. If the branch is predicted
165 ;; correctly, and predicted early enough, the branch can be completely
166 ;; eliminated from the instruction stream. Some branches can
167 ;; therefore appear to require zero cycle to execute. We assume that
168 ;; all branches are predicted correctly, and that the latency is
169 ;; therefore the minimum value.
171 (define_insn_reservation "mp626_branch_op" 0
172 (and (eq_attr "tune" "fmp626")
173 (eq_attr "type" "branch"))
176 ;; The latency for a call is actually the latency when the result is available.
177 ;; i.e. R0 ready for int return value.
178 (define_insn_reservation "mp626_call_op" 1
179 (and (eq_attr "tune" "fmp626")
180 (eq_attr "type" "call"))